p.17
Bacterial Identification Techniques
What is VITEK MS used for?
VITEK MS is used for the identification of microorganisms using mass spectrometry.
p.41
Streptococcus Species and Their Identification
What are the five medically important groups of β-haemolytic Streptococcus?
Group A – S. pyogenes, Group B – S. agalactiae, Group C – S. dysgalactiae subsp equisimilis, Group D – S. gallolyticus or Enterococcus, Group G – S. dysgalactiae subsp equisimilis.
p.15
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What are the three values that contribute to the Bruker MALDI-TOF score?
1. Number of peaks in the reference spectrum matching the test spectrum. 2. Number of peaks in the test spectrum matching the reference spectrum. 3. Peak height symmetry of the matching peaks.
p.25
Staphylococcus Species and Pathogenicity
What is Protein A and its function?
Protein A is a surface protein that can bind the Fc region of immunoglobulin G (IgG) antibody.
p.62
Gram Positive Rods/Bacilli and Their Clinical Importance
What are the clinically important species of Bacillus?
B. anthracis and B. cereus are clinically important species; others are contaminants.
p.62
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the Gram stain characteristic of Bacillus species?
They are large Gram-positive straight edged rods, but clinical specimen isolates can be Gram variable or appear Gram-negative.
p.25
Staphylococcus Species and Pathogenicity
What is the significance of a capsule or slime layer in bacteria?
The capsule or slime layer helps bacteria resist phagocytosis and enhances their virulence.
p.55
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the resistance level associated with the van B gene?
Intermediately to highly resistant to vancomycin (e.g. 16 – 256 μg/mL) but sensitive to teicoplanin, and it is plasmid-borne.
p.65
Gram Positive Rods/Bacilli and Their Clinical Importance
Do Corynebacterium form spores?
No, Corynebacterium do not form spores.
p.56
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
How does exposure to other patients affect the risk of acquiring VRE?
Proximity to other patients who are colonized with VRE, especially those with diarrhea and high VRE counts, increases the risk.
p.54
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the current status of VRE cases in Hong Kong?
VRE cases in Hong Kong are currently under control.
p.11
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is necessary to prevent memory effects after using the target slides?
The target slides need to be thoroughly washed after use.
p.25
Staphylococcus Species and Pathogenicity
What role does the enzyme coagulase play in bacterial pathogenesis?
Coagulase helps bacteria evade the immune response by promoting blood clotting.
p.36
Streptococcus Species and Their Identification
What type of anaerobes are most Streptococcus species?
Most are facultative anaerobes; some are fastidious and require CO2.
p.32
Coagulase-Negative Staphylococcus (CNS) and Their Role in Infections
What is the role of Coagulase-Negative Staphylococcus (CNS) in infections?
CNS is an opportunistic pathogen that can cause problems in immunocompromised patients, particularly through biofilm formation in catheterized patients and prosthetic valve endocarditis.
p.36
Streptococcus Species and Their Identification
At what temperature do Streptococcus species grow best?
They grow best at 37 °C on Blood Agar (BA) and Chocolate agar.
p.32
Coagulase-Negative Staphylococcus (CNS) and Their Role in Infections
How does Coagulase-Negative Staphylococcus (CNS) differ from Staphylococcus aureus?
CNS lacks many virulence factors that are present in Staphylococcus aureus.
p.53
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
Why is VRE a concern in healthcare settings?
VRE is resistant to vancomycin, making infections difficult to treat and increasing the risk of complications.
p.39
Streptococcus Species and Their Identification
What invasive diseases can Streptococcus pneumoniae cause?
Otitis media, sinusitis, and meningitis
p.61
Gram Positive Rods/Bacilli and Their Clinical Importance
What are the two main categories of Gram positive rods based on spore formation?
Spore forming Bacillus and Non-spore forming rods.
p.44
Streptococcus Species and Their Identification
What are some clinical conditions caused by Streptococcus species?
Pharyngitis, sore throat, tonsillitis, scarlet fever, wound infections, and necrotizing fasciitis.
p.52
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What does VRE stand for?
Vancomycin-resistant Enterococcus
p.26
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is MRSA?
MRSA stands for Methicillin-Resistant Staphylococcus aureus, a strain of Staphylococcus aureus that has developed resistance to methicillin and other antibiotics.
p.67
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the Gram stain morphology of Listeria?
Gram positive short rods.
p.31
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is the purpose of MRSA screening by PCR in ICU patients at PWH?
To screen all ICU patients for MRSA at admission to prevent ICU spread of MRSA.
p.14
Bacterial Identification Techniques
How should the microorganism be transferred to the tube?
Transfer a large, single colony of microorganism to the tube; more than one colony may be needed if the microorganism is small.
p.13
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
Why is formic acid used in the direct transfer method?
Adding formic acid improves the disruption of the cells and is especially recommended for Gram-positive bacteria and yeasts.
p.51
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the vancomycin sensitivity of most Enterococcus species?
Most Enterococcus species are vancomycin sensitive, but vancomycin-resistant Enterococcus (VRE) emerges.
p.23
Staphylococcus Species and Pathogenicity
What is the shape and arrangement of Staphylococcus aureus?
Gram-positive cocci in 'grape-like' clusters.
p.60
Gram Positive Rods/Bacilli and Their Clinical Importance
What are the most common isolates of Gram positive rods/bacilli?
Bacillus, Corynebacterium, and Lactobacillus.
p.22
Staphylococcus Species and Pathogenicity
What is the function of coagulase in Staphylococcus species?
Coagulase converts fibrinogen to fibrin, leading to clot formation, which helps the bacteria resist phagocytosis.
p.26
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is the primary factor contributing to the development of drug-resistant Staphylococcus aureus?
The overuse and misuse of antibiotics are the primary factors contributing to the development of drug-resistant Staphylococcus aureus.
p.15
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
How is the final Bruker MALDI-TOF score calculated?
The three values are multiplied together, normalized to 1000, and then the base 10 logarithm is taken.
p.51
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the clinical significance of Enterococcus species?
They are normal flora of the intestinal tract and are associated with bacteraemia, endocarditis, wound and soft tissue infections, as well as nosocomial urinary tract infections.
p.64
Gram Positive Rods/Bacilli and Their Clinical Importance
What infections is Bacillus cereus associated with?
Bacillus cereus is associated with gastrointestinal infections, local infections, and systemic infections.
p.65
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the shape and arrangement of Corynebacterium?
Corynebacterium are pleomorphic Gram positive rods that can appear in V-shaped or Chinese character formations.
p.67
Gram Positive Rods/Bacilli and Their Clinical Importance
How does the colony morphology of Listeria compare to S. agalactiae?
Colony and Gram stain morphology may resemble S. agalactiae (GBS).
p.51
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the resistance profile of E. faecium?
E. faecium is resistant to penicillin and ampicillin.
p.35
Gram Positive Cocci and Their Clinical Significance
What is the shape and arrangement of Micrococcus?
Gram positive cocci in tetrads.
p.46
Streptococcus Species and Their Identification
What is the significance of the CAMP factor in the CAMP test?
It enlarges the area of haemolysis formed by the β-haemolysin from S. aureus.
p.6
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
How does laser desorption work in MALDI-TOF?
The matrix with crystallized sample is fired with a laser beam, causing the matrix to absorb laser energy, convert it to heat, and trigger vaporization and desorption of the sample.
p.62
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the catalase test result for Bacillus species?
Bacillus species are catalase-positive.
p.38
Streptococcus Species and Their Identification
What conditions enhance the growth of Streptococcus pneumoniae?
Better growth in CO2 or anaerobic conditions.
p.23
Staphylococcus Species and Pathogenicity
What is the appearance of Staphylococcus aureus colonies on blood agar?
White to golden yellow convex colonies, mostly β-haemolytic.
p.9
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is the primary use of MALDI-TOF mass spectrometry?
It is primarily used for the identification of biomolecules, including proteins and microorganisms.
p.60
Gram Positive Rods/Bacilli and Their Clinical Importance
Why is Gram stain morphology important in the classification of Gram positive rods?
It is useful for initial classification.
p.11
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What are the two types of target slides used in Biotyper?
Disposable, single use only slides (MBT Biotarget 96) and reusable, ground steel target plates with hydrophobic target rings.
p.11
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
Why does the laser require an extremely flat surface for the target plate?
The target plate will become unusable if dropped or bent.
p.19
Gram Positive Cocci and Their Clinical Significance
Where are Gram positive cocci typically found as normal flora?
In most body sites covered with skin or lined with mucous membranes.
p.52
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
When was VRE first reported?
In 1986 in France and the UK.
p.29
Methicillin-Resistant Staphylococcus aureus (MRSA)
What distinguishes CA-MRSA from HA-MRSA?
CA-MRSA (Community-associated MRSA) strains are isolated from individuals in the community without recent healthcare exposure, affecting younger and healthier individuals.
p.50
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What biochemical tests are Enterococcus positive for?
PYR, bile esculin, and 6.5% NaCl.
p.14
Bacterial Identification Techniques
What is the first step in the Tube Extraction (FA extraction) procedure?
Add 300 μL of water to each microcentrifuge tube.
p.38
Streptococcus Species and Their Identification
What is the shape and arrangement of Streptococcus pneumoniae?
Gram-positive diplococci or in short chains.
p.47
Streptococcus Species and Their Identification
What serious conditions are associated with Group B Streptococcus (GBS) in neonates?
GBS is associated with stillbirth and life-threatening neonatal infections such as meningitis, septicemia, and pneumonia.
p.62
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the typical appearance of Bacillus colonies?
They usually form large whitish-greyish, spreading colonies with irregular edges.
p.16
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What score value indicates that an organism can be reported to the genus and species level using Bruker MALDI-TOF?
A score value greater than 2.00 indicates that an organism can be reported to the genus and species level.
p.38
Streptococcus Species and Their Identification
What are the characteristics of the colonies of Streptococcus pneumoniae?
Small, grey colonies that may be mucoid, dry, or umbilicated.
p.52
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What was banned in the livestock industry by the European Union in 1997?
The widespread use of avoparcin.
p.48
Streptococcus Species and Their Identification
What type of hemolysis is associated with Streptococcus dysgalactiae subsp equisimilis?
Big β-haemolytic large colony.
p.47
Streptococcus Species and Their Identification
What antibiotic is Group B Streptococcus (GBS) sensitive to?
GBS is sensitive to penicillin.
p.48
Streptococcus Species and Their Identification
Which groups does Streptococcus dysgalactiae subsp equisimilis belong to?
Streptococcus group C and G.
p.20
Gram Positive Cocci and Their Clinical Significance
Which Gram positive cocci are typically found in pairs?
Streptococcus pneumoniae is typically found in pairs.
p.54
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
When was the first case of VRE reported in Hong Kong?
The first case of VRE in Hong Kong was an imported case in 1997.
p.60
Gram Positive Rods/Bacilli and Their Clinical Importance
What should be correlated with clinical specimens to determine clinical significance?
Specimen types, clinical information, and clinical significance.
p.25
Staphylococcus Species and Pathogenicity
What are cytolytic toxins, haemolysins, and leukotoxins produced by bacteria aimed at?
They are aimed to evade elimination by host defense mechanisms.
p.69
Gram Positive Rods/Bacilli and Their Clinical Importance
What are the optimal growth conditions for Actinomyces?
Microaerophilic (reduced oxygen tension) or anaerobic conditions.
p.29
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is HA-MRSA and how is it transmitted?
HA-MRSA (Hospital-associated MRSA) circulates and is transmitted to individuals in healthcare facilities, with risk factors including long-term hospitalization, surgery, and ICU stays.
p.55
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What does the van A gene confer?
High-level resistance to both vancomycin and teicoplanin (e.g. >256 μg/mL), and it is plasmid-borne.
p.28
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is the staphylococcal cassette chromosome mec (SCC mec)?
A genomic region inserted into the Staphylococcal genome that contains the mecA gene and other genes.
p.8
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
How is the mass spectrum obtained from a sample used in bacterial identification?
It is compared to reference strains in a database for closely matched bacterial identity.
p.21
Staphylococcus Species and Pathogenicity
What is the shape and arrangement of Staphylococcus?
Gram positive cocci in clusters.
p.32
Coagulase-Negative Staphylococcus (CNS) and Their Role in Infections
What is prosthetic valve endocarditis and how is it related to Coagulase-Negative Staphylococcus (CNS)?
Prosthetic valve endocarditis occurs in patients with artificial devices and poor blood circulation, where CNS can be a causative agent.
p.64
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is the significance of the Bruker MALDI-TOF in identifying Bacillus species?
Bruker MALDI-TOF can identify closely related species like Bacillus anthracis and Bacillus cereus, but Bacillus anthracis is not included in the MALDI Biotyper database.
p.43
Streptococcus Species and Their Identification
What are the two haemolysins produced by Streptococcus pyogenes?
Streptolysin S (stable in oxygen) and Streptolysin O (labile in oxygen).
p.63
Gram Positive Rods/Bacilli and Their Clinical Importance
What are the symptoms of gastrointestinal anthrax?
Mild diarrhea, fever, and chills
p.53
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the prevalence of VRE in Canada?
VRE prevalence in Canada varies by region and healthcare facility, with increasing reports in recent years.
p.56
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
Who are considered susceptible hosts for VRE colonization?
Severely ill patients, those receiving multiple and prolonged courses of antimicrobial therapy, and organ transplant recipients.
p.60
Gram Positive Rods/Bacilli and Their Clinical Importance
Can isolates from clinical specimens be contaminants?
Yes, they may be clinically significant or contaminants.
p.69
Gram Positive Rods/Bacilli and Their Clinical Importance
Where are Actinomyces commonly found in the human body?
Flora of skin, mouth, gut, and vagina.
p.36
Streptococcus Species and Their Identification
What is the shape and arrangement of Streptococcus bacteria?
Gram-positive cocci in chains, with S. pneumoniae appearing as diplococci.
p.50
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the Group D antigen status of Enterococcus?
Usually Group D antigen positive.
p.61
Gram Positive Rods/Bacilli and Their Clinical Importance
What are two examples of non-spore forming Gram positive rods?
Lactobacillus and Listeria.
p.46
Streptococcus Species and Their Identification
What does CAMP stand for in the CAMP test?
Christie, Atkins, Munch-Petersen.
p.31
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is the turnaround time (TAT) for MRSA PCR compared to MRSA culture?
The TAT for MRSA PCR is 24 hours, while MRSA culture takes 3 days.
p.55
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the resistance profile of the van M gene?
High-level resistance to vancomycin and usually teicoplanin (e.g. >256 μg/mL), and it is chromosome-borne.
p.64
Gram Positive Rods/Bacilli and Their Clinical Importance
How does Bacillus cereus respond to penicillin?
Bacillus cereus is resistant to penicillin.
p.43
Streptococcus Species and Their Identification
What are the characteristics of Streptococcus pyogenes colonies?
Large (>0.5 mm), grey, translucent colony with a wide zone of β-haemolysis.
p.27
Methicillin-Resistant Staphylococcus aureus (MRSA)
When was MRSA first isolated in the United States?
MRSA was first isolated in the United States in 1968.
p.47
Streptococcus Species and Their Identification
When should all pregnant women be screened for Group B Streptococcus (GBS)?
All pregnant women should be screened for GBS at 35 to 37 weeks gestation.
p.65
Gram Positive Rods/Bacilli and Their Clinical Importance
What infections are associated with C. urealyticum?
C. urealyticum is associated with urinary tract infections.
p.9
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What does MALDI-TOF stand for?
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight
p.18
Gram Positive Rods/Bacilli and Their Clinical Importance
Which Gram positive organism is known for causing tuberculosis?
Mycobacterium tuberculosis is the Gram positive organism known for causing tuberculosis.
p.54
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What types of departments have reported sporadic cases of VRE colonization or infections in Hong Kong?
Sporadic cases of VRE colonization or infections have been reported in renal, medicine, and orthopaedics departments.
p.39
Streptococcus Species and Their Identification
What are the treatments for infections caused by Streptococcus pneumoniae?
Penicillin and cefotaxime
p.8
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What does the mass spectral fingerprint in MALDI-TOF represent?
Desorbed microbial cell components, mainly intracellular proteins.
p.62
Gram Positive Rods/Bacilli and Their Clinical Importance
How do Bacillus spores appear in smears?
Spores may not be visible in direct smears but appear in colony smears.
p.64
Gram Positive Rods/Bacilli and Their Clinical Importance
What syndrome is Bacillus cereus commonly linked to?
Bacillus cereus is involved in food poisoning, specifically known as 'fried rice syndrome'.
p.62
Gram Positive Rods/Bacilli and Their Clinical Importance
What type of anaerobic conditions do Bacillus species prefer?
Most are facultative anaerobes, while some are obligate aerobes.
p.36
Streptococcus Species and Their Identification
How are haemolytic reactions best observed in Streptococcus?
Haemolytic reactions are best observed with transmitted light shining from behind the agar plate.
p.32
Coagulase-Negative Staphylococcus (CNS) and Their Role in Infections
What complications can arise from Coagulase-Negative Staphylococcus (CNS) in catheterized patients?
CNS can lead to biofilm formation, which complicates treatment and increases the risk of infections.
p.27
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is Methicillin-resistant Staphylococcus aureus (MRSA)?
MRSA is a strain of Staphylococcus aureus that is resistant to methicillin and other commonly used antibiotics.
p.28
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is the role of the ccr gene in SCC mec?
The ccr (cassette chromosome recombinase) gene is responsible for the attachment of the SCC mec cassette to the staphylococcal chromosome.
p.31
Methicillin-Resistant Staphylococcus aureus (MRSA)
What was the impact of implementing MRSA PCR screening on ICU-acquired MRSA infections?
ICU-acquired MRSA infections decreased after the implementation of MRSA PCR screening.
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the significance of hydrogen sulfide production in Erysipelothrix?
Erysipelothrix produces hydrogen sulfide, forming a black precipitate in triple sugar iron (TSI) agar.
p.53
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What does VRE stand for?
Vancomycin-Resistant Enterococcus
p.18
Gram Positive Cocci and Their Clinical Significance
What are the main types of Gram positive organisms?
Gram positive cocci include Staphylococcus, Micrococcus, Streptococcus, and Enterococcus. Gram positive rods/bacilli include Bacillus, Corynebacterium, Lactobacillus, Mycobacterium tuberculosis, and Actinomyces.
p.37
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
How can Enterococcus be identified in a laboratory setting?
Enterococcus can be identified through culture on selective media, testing for bile esculin hydrolysis, and checking for growth in high salt concentrations.
p.17
Bacterial Identification Techniques
Which company developed VITEK MS?
VITEK MS was developed by bioMérieux.
p.41
Streptococcus Species and Their Identification
What is the classification method for β-haemolytic Streptococcus?
Classified according to Lancefield grouping based on carbohydrate antigens on the cell wall.
p.39
Streptococcus Species and Their Identification
What are some occasional infections caused by Streptococcus pneumoniae?
Endocarditis, septic arthritis, peritonitis, pericarditis, osteomyelitis, and soft tissue infections
p.42
Streptococcus Species and Their Identification
Is Streptococcus pyogenes sensitive to bacitracin?
Yes, S. pyogenes is sensitive to bacitracin.
p.37
Streptococcus Species and Their Identification
What is the simplified identification scheme for Streptococcus?
The identification scheme typically involves assessing hemolysis patterns on blood agar, catalase test results, and further biochemical tests to differentiate species.
p.56
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What are the risk factors for colonization of Vancomycin-Resistant Enterococcus (VRE)?
Risk factors include exposure to VRE and being a susceptible host.
p.42
Streptococcus Species and Their Identification
What is the purpose of the Bacitracin test?
To screen for Streptococcus pyogenes.
p.22
Staphylococcus Species and Pathogenicity
What are the two forms of coagulase?
The two forms of coagulase are bound coagulase, which is on the cell wall and detected by slide tests or commercial tests like Staphaurex, and free coagulase, which is secreted into the extracellular environment and detected by tube tests.
p.45
Streptococcus Species and Their Identification
What is the colony appearance of Streptococcus agalactiae?
Large translucent to opaque, flat, grey-white colony.
p.26
Methicillin-Resistant Staphylococcus aureus (MRSA)
How does drug resistance in S. aureus affect treatment options?
Drug resistance in S. aureus limits treatment options, making infections harder to treat and increasing the risk of complications.
p.51
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
How does E. faecalis respond to penicillin and ampicillin?
E. faecalis is sensitive to penicillin and ampicillin.
p.29
Methicillin-Resistant Staphylococcus aureus (MRSA)
When and where was CA-MRSA first reported?
CA-MRSA was first reported in the 1990s in Australia, New Zealand, and America.
p.29
Methicillin-Resistant Staphylococcus aureus (MRSA)
What gene do CA-MRSA strains carry and what does it code for?
CA-MRSA strains carry the PVL gene (Panton-Valentine leucocidin), which codes for a cytotoxin.
p.40
Streptococcus Species and Their Identification
What is the appearance of Viridans Streptococcus colonies?
Tiny, small grey, smooth, or dull colony
p.36
Streptococcus Species and Their Identification
What characterizes alpha-prime hemolysis (α′) in Streptococcus?
A small zone of intact erythrocytes immediately adjacent to the bacterial colony, with a zone of complete red-cell hemolysis surrounding it.
p.62
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the hemolytic characteristic of most clinical Bacillus isolates?
Most clinical isolates are β-hemolytic.
p.65
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the clinical significance of C. diphtheriae?
C. diphtheriae causes diphtheria, produces diphtheria toxin, and forms a pseudomembrane in the throat.
p.7
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
How are ions accelerated in MALDI-TOF?
Ions are accelerated by an electric field of known strength.
p.38
Streptococcus Species and Their Identification
What tests indicate the sensitivity of Streptococcus pneumoniae?
Optochin sensitivity and positive bile solubility.
p.64
Gram Positive Rods/Bacilli and Their Clinical Importance
What characteristic of the toxin produced by Bacillus cereus is concerning?
The toxin produced by Bacillus cereus is resistant to heat and not easily destroyed by cooking.
p.14
Bacterial Identification Techniques
What is the final concentration of acetonitrile (ACN) needed in the procedure?
The volumes of 70% FA and ACN must be equal to achieve a final ACN concentration of 50%.
p.23
Staphylococcus Species and Pathogenicity
What are the results of the coagulase tests for Staphylococcus aureus?
Slide and tube coagulase positive.
p.15
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What does the Bruker MALDI-TOF score represent?
It represents the probability of isolate identification based on a composite score of matching peaks between reference and test spectra.
p.50
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What are the characteristics of Enterococcus?
Facultative anaerobes, Gram-positive cocci in chains, small grey-white colonies, α or γ-haemolytic, rare β-haemolytic.
p.50
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
Which two species are commonly associated with Enterococcus?
E. faecalis and E. faecium.
p.55
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the resistance mechanism of vancomycin-resistant enterococci?
Alteration of peptidoglycan synthesis pathway.
p.8
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
Why does each bacterial species produce a different mass spectrum in MALDI-TOF?
Each species has a different protein composition.
p.52
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What was the prevalence of VRE in enterococcal isolates from hospitalized patients in Europe from 1990 to 1997?
It increased from less than 1% to approximately 15%.
p.33
Staphylococcus Species and Pathogenicity
How can Staphylococcus lugdunensis be confused in identification?
May confuse with S. aureus in identification.
p.28
Methicillin-Resistant Staphylococcus aureus (MRSA)
What does the mecA gene do?
It alters penicillin binding protein 2 (PBP2) production, encoding a new PBP2a, resulting in a loss of target affinity.
p.64
Gram Positive Rods/Bacilli and Their Clinical Importance
What is a key characteristic of Bacillus cereus in terms of hemolysis?
Bacillus cereus is beta-hemolytic.
p.28
Methicillin-Resistant Staphylococcus aureus (MRSA)
Where is the SCC mec likely originated from?
It likely originated in coagulase-negative staphylococcal species.
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
What type of hemolysis does Erysipelothrix exhibit?
Erysipelothrix is α-haemolytic and forms small colonies.
p.13
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What should be done after overlaying each sample with formic acid?
Allow the formic acid to evaporate before adding the matrix solution to avoid spilling of the samples into neighboring spots.
p.55
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
Are van A and van B genes transmittable?
Yes, van A and van B are transmittable.
p.67
Gram Positive Rods/Bacilli and Their Clinical Importance
What conditions can Listeria monocytogenes cause?
Meningitis in neonates, pregnant women, and immunocompromised patients.
p.66
Gram Positive Rods/Bacilli and Their Clinical Importance
Is Lactobacillus spore-forming?
No, Lactobacillus does not form spores.
p.67
Gram Positive Rods/Bacilli and Their Clinical Importance
In what types of food is Listeria commonly found?
Dairy products, e.g., cheese and ice cream.
p.21
Coagulase-Negative Staphylococcus (CNS) and Their Role in Infections
What are coagulase-negative Staphylococcus species known for?
They are usually opportunistic pathogens, with S. lugdunensis and S. saprophyticus being notable examples.
p.67
Gram Positive Rods/Bacilli and Their Clinical Importance
What is a unique growth characteristic of Listeria?
Psychrotrophic, able to grow as low as 0°C.
p.66
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the catalase reaction of Lactobacillus?
Lactobacillus is catalase negative.
p.34
Staphylococcus Species and Pathogenicity
What biochemical tests confirm Staphylococcus saprophyticus?
Positive for urease and sucrose fermentation; negative for nitrate reductase and xylose fermentation.
p.48
Streptococcus Species and Their Identification
What infections can Streptococcus dysgalactiae subsp equisimilis cause?
Pharyngitis, skin and soft tissue infections, toxic shock-like syndrome, bacteraemia, arthritis, osteomyelitis, respiratory infections, abscesses, endocarditis, and meningitis.
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
How does Erysipelothrix respond to vancomycin?
Erysipelothrix is resistant to vancomycin, unlike most Gram-positive bacteria which are sensitive.
p.49
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is a challenge in distinguishing species within the genus Streptococcus, including gallolyticus?
They have very similar patterns in MALDI-TOF mass spectrometry.
p.69
Gram Positive Rods/Bacilli and Their Clinical Importance
What type of bacteria are Actinomyces?
Branched Gram positive rods.
p.44
Streptococcus Species and Their Identification
What complications can arise if Streptococcus infections are left untreated?
Rheumatic heart disease and acute glomerulonephritis.
p.33
Staphylococcus Species and Pathogenicity
What is the coagulase test result for Staphylococcus lugdunensis?
May be positive for bound coagulase, but negative for free coagulase.
p.45
Streptococcus Species and Their Identification
What type of hemolysis is typically associated with Streptococcus agalactiae?
Narrow zone of β-haemolytic; some strains are γ-haemolytic.
p.69
Gram Positive Rods/Bacilli and Their Clinical Importance
What clinical condition is associated with Actinomyces?
Actinomycosis, which involves abscesses of the jaw and sinus tracts to the skin surface.
p.19
Bacterial Identification Techniques
What specific tests are used to identify species of Gram positive cocci?
Coagulase, optochin, bacitracin, PYR, and/or Lancefield tests.
p.25
Staphylococcus Species and Pathogenicity
What is a common issue related to bacterial infections?
Drug resistance is a significant concern in bacterial infections.
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the shape and Gram staining characteristic of Erysipelothrix?
Erysipelothrix is a Gram positive curved-shaped rod.
p.43
Streptococcus Species and Their Identification
What type of bacteria is Streptococcus pyogenes?
Group A Streptococcus which contains Group A antigen.
p.14
Bacterial Identification Techniques
What is the purpose of adding ethanol (EtOH) in the extraction procedure?
To help in the extraction process by vortexing thoroughly after adding 900 μL of ethanol.
p.47
Streptococcus Species and Their Identification
What postpartum infections can Group B Streptococcus (GBS) cause in pregnant women?
GBS can cause postpartum infections such as bacteremia and endometritis in pregnant women.
p.40
Streptococcus Species and Their Identification
How does the growth of Viridans Streptococcus change with CO2?
Growth is enhanced with CO2
p.63
Gram Positive Rods/Bacilli and Their Clinical Importance
What are the three forms of anthrax?
Gastrointestinal anthrax, Cutaneous anthrax, Inhalational anthrax
p.20
Gram Positive Cocci and Their Clinical Significance
Which Gram positive cocci are typically found in clusters?
Staphylococcus and Micrococcus are typically found in clusters.
p.6
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What happens to sample molecules during the ionization step in MALDI-TOF?
Sample molecules are ionized and transferred into a gas phase, generating generally singly charged ions from analytes.
p.24
Staphylococcus Species and Pathogenicity
From where can Staphylococcus aureus be isolated?
Most clinical specimens, either as a colonizer or a pathogen.
p.16
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What additional information does the Biotyper provide along with score values?
The Biotyper provides matching hints with further taxonomical information or cautionary details to prevent misinterpretation.
p.67
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is required for reliable species identification of Listeria using Bruker MALDI-TOF?
Extraction must be performed.
p.14
Bacterial Identification Techniques
What should be done with the supernatant after centrifugation?
Pipette 1 μL of supernatant onto a steel target, avoiding the pellet at the bottom, and air dry.
p.27
Methicillin-Resistant Staphylococcus aureus (MRSA)
What is the drug of choice for treating MRSA?
Vancomycin is the drug of choice for MRSA.
p.24
Staphylococcus Species and Pathogenicity
What enzymes does Staphylococcus aureus produce that contribute to soft-tissue infections?
Hyaluronidase and lipase.
p.44
Streptococcus Species and Their Identification
What is a key feature of the pathogenesis of Streptococcus species?
They contain a capsule composed of hyaluronic acid to prevent phagocytosis.
p.19
Bacterial Identification Techniques
What is the first step in identifying potential pathogens among Gram positive cocci?
Screening tests to group into genera, such as catalase and oxidase tests.
p.30
Bacterial Identification Techniques
What is a common method used in bacterial culture to increase sensitivity?
Broth based enrichment with NaCl salt.
p.47
Streptococcus Species and Their Identification
What percentage of healthy women may colonize with Group B Streptococcus (GBS) in the genital tract?
Up to 30% of healthy women may colonize with GBS in the genital tract.
p.13
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is the first step in the direct transfer method for MALDI-TOF mass spectrometry?
Smear a thin film of biological material directly onto a clean MALDI target using a pipette tip or wooden toothpick.
p.55
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What does the van C gene indicate?
Intermediately resistant to vancomycin (e.g. 8 – 16 μg/mL) but sensitive to teicoplanin, and it is chromosome-borne.
p.67
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the catalase test result for Listeria?
Catalase positive (S. agalactiae is negative).
p.6
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is the purpose of the energy-absorbent matrix in MALDI-TOF?
The matrix is used to prepare the sample for analysis by mixing or coating it, which entraps and co-crystallizes the sample when dried.
p.52
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What led to the increase in VRE prevalence in healthcare settings?
Increased consumption of vancomycin.
p.16
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What score value allows for reporting to the genus level only in Bruker MALDI-TOF?
A score value between 1.70 and 2.00 allows for reporting to the genus level only.
p.34
Staphylococcus Species and Pathogenicity
What is a common infection caused by Staphylococcus saprophyticus?
Urinary tract infection in young women.
p.14
Bacterial Identification Techniques
What should be done after decanting the ethanol?
Centrifuge for 2 minutes to remove excess ethanol.
p.34
Staphylococcus Species and Pathogenicity
How does Staphylococcus saprophyticus react to coagulase tests?
May be positive for bound coagulase, but negative for free coagulase.
p.65
Gram Positive Rods/Bacilli and Their Clinical Importance
What type of infections can C. jeikeium cause?
C. jeikeium can cause opportunistic infections.
p.23
Staphylococcus Species and Pathogenicity
What can occur with prolonged antibiotic therapy in patients with Staphylococcus aureus infections?
Small variant colonies (SVC) can occur.
p.16
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What should any score from Bruker MALDI-TOF be correlated with?
Any score should be correlated with gram stain and culture characteristics, clinical context, and biochemical features.
p.27
Methicillin-Resistant Staphylococcus aureus (MRSA)
Where was MRSA originally localized?
MRSA was originally localized in hospital environments.
p.49
Streptococcus Species and Their Identification
What infections can Streptococcus gallolyticus cause?
Bacteraemia and endocarditis
p.48
Bacterial Identification Techniques
What follow-up method is used after blood culture for Streptococcus dysgalactiae?
Follow up by VITEK; other sites report Streptococcus dysgalactiae.
p.33
Staphylococcus Species and Pathogenicity
What biochemical tests is Staphylococcus lugdunensis positive for?
Positive for ornithine decarboxylase and PYR.
p.31
Methicillin-Resistant Staphylococcus aureus (MRSA)
What happens if a patient tests positive for MRSA during screening?
The patient will be isolated in a single room, and all healthcare workers will comply strictly with contact precautions.
p.20
Gram Positive Cocci and Their Clinical Significance
What are the characteristics of Gram positive cocci?
Gram positive cocci can be found in clusters (e.g., Staphylococcus, Micrococcus), chains (e.g., Streptococcus, Enterococcus), or pairs (e.g., Streptococcus pneumoniae).
p.14
Bacterial Identification Techniques
What is the centrifuge speed and duration after adding ethanol?
Centrifuge at maximum speed (13,000 to 15,000 rpm) for 2 minutes.
p.7
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What principle does MALDI-TOF use to determine an ion's mass-to-charge ratio?
MALDI-TOF uses time of flight measurements to determine an ion's mass-to-charge ratio.
p.21
Staphylococcus Species and Pathogenicity
What is the role of Staphylococcus intermedius in human disease?
It is part of animal flora and can occupationally cause human disease.
p.64
Gram Positive Rods/Bacilli and Their Clinical Importance
What is a common practice that leads to Bacillus cereus outbreaks?
The common practice of storing boiled rice at room temperature for subsequent preparation of fried rice has been implicated in Bacillus cereus outbreaks.
p.66
Gram Positive Rods/Bacilli and Their Clinical Importance
What type of colony does Lactobacillus form?
Lactobacillus forms tiny, α-hemolytic grey colonies.
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
Where is Erysipelothrix commonly found?
Erysipelothrix is found in soil, water, and the digestive tract of many animals.
p.38
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
Which MALDI-TOF system can identify Streptococcus pneumoniae?
Bruker MALDI-TOF and Biomerieux MALDI-TOF.
p.48
Streptococcus Species and Their Identification
How does the virulence of Streptococcus dysgalactiae subsp equisimilis compare to S. pyogenes?
It is relatively less virulent than S. pyogenes.
p.24
Staphylococcus Species and Pathogenicity
What are some clinical conditions associated with Staphylococcus aureus?
Food poisoning and Toxic Shock Syndrome.
p.65
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the catalase reaction of Corynebacterium?
Corynebacterium are catalase positive.
p.67
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the motility characteristic of Listeria?
Motility positive (S. agalactiae is non-motile).
p.66
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the shape and arrangement of Lactobacillus?
Lactobacillus are long and filamentous rods in chains.
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the catalase reaction of Erysipelothrix?
Erysipelothrix is catalase-negative.
p.35
Gram Positive Cocci and Their Clinical Significance
What are the catalase and oxidase results for Micrococcus?
Catalase positive and oxidase positive.
p.20
Gram Positive Cocci and Their Clinical Significance
Which Gram positive cocci are typically found in chains?
Streptococcus and Enterococcus are typically found in chains.
p.21
Coagulase-Negative Staphylococcus (CNS) and Their Role in Infections
Are other coagulase-negative Staphylococcus species pathogenic?
No, they are usually non-pathogenic.
p.35
Gram Positive Cocci and Their Clinical Significance
How does Micrococcus respond to Bacitracin?
Susceptible to Bacitracin (0.04U).
p.57
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What is the duration of persistent colonization of VRE in the GI tract?
VRE can persistently colonize the GI tract for 3 months to 2 years.
p.66
Gram Positive Rods/Bacilli and Their Clinical Importance
What role does Lactobacillus play in vaginal health?
Lactobacillus helps maintain the acidic environment needed for healthy vaginal flora.
p.57
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What are the implications of antibiotic resistance in VRE?
Antibiotic resistance in VRE leads to limited treatment options and the potential transfer of resistance to other organisms.
p.13
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is the recommended colony size for the direct transfer method?
A colony size of a pin head or poppy seed is generally enough.
p.16
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What does a score value less than 1.7 indicate in Bruker MALDI-TOF?
A score value less than 1.7 indicates that no organism identification is possible.
p.13
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is the final step in the direct transfer method?
Allow the samples to dry at room temperature.
p.14
Bacterial Identification Techniques
What is the next step after removing excess ethanol?
Add 50 μL of 70% FA and vortex thoroughly, letting it stand for approximately 5 minutes.
p.27
Methicillin-Resistant Staphylococcus aureus (MRSA)
What was the percentage of MRSA among S. aureus isolates in ICUs in 1999?
In 1999, MRSA accounted for 50% of S. aureus isolates from patients in ICUs.
p.63
Gram Positive Rods/Bacilli and Their Clinical Importance
What is the fatal form of anthrax?
Inhalational anthrax, which may result in respiratory distress and death
p.66
Gram Positive Rods/Bacilli and Their Clinical Importance
Where is Lactobacillus commonly found in the human body?
Lactobacillus is found in the oral cavity, gastrointestinal tract, and female genital tract.
p.27
Methicillin-Resistant Staphylococcus aureus (MRSA)
When was Vancomycin-resistant Staphylococcus aureus (VRSA) reported?
VRSA was reported in Japan in 1996.
p.27
Methicillin-Resistant Staphylococcus aureus (MRSA)
What percentage of Staphylococcus aureus isolates from hospitalized patients in the US were MRSA by the early 1990s?
By the early 1990s, MRSA accounted for 20-25% of Staphylococcus aureus isolates from hospitalized patients in the US.
p.57
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
Why do we care about VRE despite its low infection rate?
11-35% of carriers can develop infections, which are associated with increased mortality, longer hospital stays, ICU admissions, surgical procedures, and higher costs.
p.24
Staphylococcus Species and Pathogenicity
What are the characteristics of cellulitis caused by Staphylococcus aureus?
Involves dermis, red, hot, swelling, and painful.
p.7
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
How does the mass-to-charge ratio affect the velocity of ions in MALDI-TOF?
Heavier ions of the same charge reach lower speeds, while ions with higher charge will increase in velocity.
p.35
Gram Positive Cocci and Their Clinical Significance
Where is Micrococcus usually found?
Usually contaminants from skin, mucosa, oropharynx, or environments.
p.35
Gram Positive Cocci and Their Clinical Significance
What is Micrococcus resistant to?
Resistant to nitrofurantoin.
p.43
Streptococcus Species and Their Identification
What is the bacitracin sensitivity of Streptococcus pyogenes?
Streptococcus pyogenes is bacitracin sensitive.
p.6
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
How are ions separated in MALDI-TOF?
Ions are accelerated through a vacuum by an applied electrical field and are separated based on their mass-to-charge ratio (m/z) before detection.
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
What disease does Erysipelothrix cause?
Erysipelothrix causes erysipeloid, which is characterized by erythematous edema.
p.40
Streptococcus Species and Their Identification
What oral health issues are caused by Viridans Streptococcus?
Responsible for gingivitis and dental caries
p.14
Bacterial Identification Techniques
What is the final step in the Tube Extraction procedure?
Overlay with 1 μL of matrix and allow to dry at room temperature.
p.66
Gram Positive Rods/Bacilli and Their Clinical Importance
Why is Lactobacillus considered a probiotic?
Lactobacillus is considered a probiotic because it is a good bacteria.
p.46
Streptococcus Species and Their Identification
What is the CAMP test used for?
To screen for S. agalactiae.
p.7
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What happens to ions with the same charge in MALDI-TOF?
Ions with the same charge have the same kinetic energy after acceleration.
p.40
Streptococcus Species and Their Identification
What is the significance of Viridans Streptococcus in clinical conditions?
Associated with endocarditis, bacteraemia, and meningitis; accounts for 50% to 60% of cases of subacute bacterial endocarditis (SBE)
p.7
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What determines the arrival time of ions at the detector in MALDI-TOF?
The mass-to-charge ratio determines the arrival time of ions at the detector.
p.34
Bacterial Identification Techniques
What commercial identification cards can be used for Staphylococcus saprophyticus?
Vitek 2 GPI and API Staph.
p.34
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
Which mass spectrometry technique is used for identifying Staphylococcus saprophyticus?
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF).
p.57
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
What may be required during a VRE outbreak?
Active surveillance may be required during a VRE outbreak.
p.63
Gram Positive Rods/Bacilli and Their Clinical Importance
What is a characteristic of cutaneous anthrax?
Seldom fatal, causes wound infection known as 'Malignant pustule'
p.24
Staphylococcus Species and Pathogenicity
What type of infections can Staphylococcus aureus cause when it penetrates intact skin?
Skin infections and skin lesions.
p.48
Streptococcus Species and Their Identification
How does Streptococcus dysgalactiae subsp equisimilis react with group A antiserum?
It may cross-react with group A antiserum.
p.57
Enterococcus and Vancomycin-Resistant Enterococcus (VRE)
How long can VRE survive in the environment?
VRE can survive in the environment for prolonged periods, ranging from 7 days to 4 months.
p.63
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
Can Bacillus anthracis be identified by MALDI-TOF?
No, it cannot be identified by MALDI-TOF
p.68
Gram Positive Rods/Bacilli and Their Clinical Importance
Who is at risk for contracting erysipeloid?
Erysipelothrix is an occupational disease commonly found in butchers and fishermen.
p.48
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry
What is a challenge in distinguishing Streptococcus dysgalactiae subsp equisimilis from other species?
Species canis and dysgalactiae have very similar patterns, making distinction difficult.
p.35
Gram Positive Cocci and Their Clinical Significance
In which patients may Micrococcus act as an opportunistic pathogen?
In immunocompromised patients.
