Bacte Part 2

• Alpha hemolytic Staphylococci have a colony surrounded by a green or brown zone.
• Beta hemolytic Staphylococci have a colony surrounded by a clear/colorless zone.
• Gamma non-hemolytic Staphylococci have a colony surrounded by a clear/colorless zone.
• Alpha prime Staphylococci have a colony surrounded with an alpha zone of hemolysis and an outer beta zone when grown in refrigerated conditions.
• Enteroinvasive Escherichia coli (EIEC) invades the intestinal epithelium causing Shigella-like infection.
• The stool of a person with Enteropathogenic Escherichia coli (EPEC) infection is typically watery with mucus but no blood.
• Escherichia coli O157:H7 is the only strain that is sorbitol negative (colorless colonies) on SMAC.
• Enterohemorrhagic Escherichia coli (EHEC)/Verotoxic E.coli (VTEC) are most frequently associated with certain serotypes such as Escherichia coli O157:H7.
• Staphylococcus aureus have golden yellow colonies, Staphylococcus citreus have lemon yellow colonies, and Staphylococcus albus have porcelain white colonies.
• Enterohemorrhagic Escherichia coli (EHEC)/Verotoxic E.coli (VTEC) produce verotoxin, a cytotoxin that resembles that of Shigella dysenteriae, and can cause Hemolytic Uremic Syndrome (HUS), the most severe manifestation of EHEC.
• Enteropathogenic Escherichia coli (EPEC) is a non-invasive, produces no toxin, nosocomial pathogen seen in newborns and infants, and is responsible for outbreaks of diarrhea among hospital nurseries.
• Other Escherichia coli ferment sorbitol, resulting in Pink colonies.
• The stool of a person with Enteroinvasive Escherichia coli (EIEC) infection typically contains Red Blood Cells (RBC), neutrophils and mucus, which is watery with blood.
• Dysentery, caused by Enteroinvasive Escherichia coli (EIEC), usually occurs in young children living in areas of poor sanitation.
• Staphylococcus aureus are identified by their golden yellow colonies on Loeffler’s Serum Slant (LSS).
• Streptococci that form satellites are known as satelliting-streptococci.
• Staphylococcus citreus are identified by their lemon yellow colonies on Loeffler’s Serum Slant (LSS).
• Pneumoniae from Viridans Streptococci are sensitive to Neufeld-Quellung and have positive results for inulin fermentation, bile solubility, and Optochin (Taxo P).
• Neisseria meningitidis can cause life-threatening, acute, purulent meningitis, which may be accompanied by the appearance of petechiae or rash that is associated with meningococcal bacteremia (meningococcemia).
• Moraxella catarrhalis, previously known as Branhamella catarrhalis or Neisseria catarrhalis, is most commonly involved in respiratory tract infections, including sinusitis and pneumonia, and lower respiratory tract infections often target elderly patients and those with chronic obstructive pulmonary disease.
• Gram-negative cocci, known as Neisseria, are obligate aerobes, capnophilic, and require 5 to 10% CO2.
• Neisseria are oxidase positive.
• Neisseria are non-motile and positive for catalase except for Neisseria elongata.
• Streptococci that require thiol (cysteine) are known as thiol-requiring streptococci.
• Neisseria gonorrhoeae is the leading cause of sexually transmitted disease (STD) and can cause genital infections such as purulent urethritis in males and cervicitis in females, which may be asymptomatic.
• Streptococci that need cysteine or pyridoxal (vitamin B6) are known as nutritionally variant streptococci.
• Malonate utilization test determines if an organism can utilize malonate as a sole source of carbon.
• ONPG test is a rapid test to detect B-galactosidase, which identifies Late LF.
• Phenylalanine deaminase is an enzyme that removes amino group (NH2) from an amino acid.
• Urease Test detects the presence of urease-producing bacteria, such as Proteus, Providencia, Morganella, and Citrobacter, Klebsiella, Enterobacter, Yersinia, Serratia.
• Glucose is fermented in mixed acid production, resulting in the production of LAFS (lactic, acetic, formic, succinic acid).
• ETEC is responsible for traveler’s diarrhea, also known as “Montezuma’s revenge”, and childhood diarrhea characterized by profuse watery stool.
• Citrate utilization test determines if an organism can utilize citrate as a sole source of carbon.
• Decarboxylase is an enzyme that removes the carboxyl group (COOH) from an amino acid.
• The toxin produced by ETEC causes diarrhea by producing or mediating the secretion of H2O and electrolytes.
• LTs are closely related in structure and function to cholera toxin, while STs result in net intestinal fluid secretion by stimulating guanylate cyclase.
• Gelatin liquefaction test determines if an organism can breakdown gelatin into amino acids.
• Voges Proskauer test detects the production of acetoin or acetyl methyl carbinol, which are metabolic byproducts of certain bacteria.
• Enterotoxigenic Escherichia coli (ETEC) produces heat labile (LT) and/or heat stable (ST) enterotoxins, with both toxin genes residing on a plasmid.
• MRVP test detects the production of mixed acid by an organism, indicating its ability to overcome the neutralizing effect of the buffer.