Microbiology Flashcards
What are the 4 groups of exotoxins that Staph aureus can secrete?
Superantigens - these have superantigen activities that induce toxic shock syndrome (TSS). An example is TSST-1 enterotoxin type B, which causes TSS associated with tampon use.
Exfoliative (EF) toxins - EF toxins are implicated in the disease staphylococcal scalded-skin syndrome (SSSS), which most commonly occurs in infants and young children.
Cell membrane toxins: examples include the alpha, beta and delta toxins, which increase invasiveness and virulence.
Biocomponent toxins - an example is Panton-Valentine leukocidin (PVL), which is associated with severe necrotising pneumonia in children.
Name 4 Abx MRSA is sensitive to?
Vancomycin
Daptmycin
Teicoplanin
Linezolid
Which Abx causes greatest risk of C diff?
Clindamycin
Tetracyclines are not associated with C diff risk
List 5 bacteria with flagella as virulence factors?
Vibrio cholerae Helicobacter pylori Campylobacter jejuni Salmonella typhi Escherichia coli
What is the risk of Toxoplasmosis in pregnancy?
If this is contracted for the first time in pregnancy or in the 3 months before conception, it can cause foetal abnormalities or miscarriage. Around a third of foetuses will be affected if a primary infection occurs during pregnancy or just before conception.
Features include the following: Microcephaly Retinochoroiditis Hydrocephalus Microphthalmia
If cytomegalovirus is contracted during pregnancy, what are the signs in the foetus?
IUGR Jaundice Hepatosplenomegaly Petechiae Thrombocytopenia Microcephaly Deafness Mental retardation
What are the risks of contracting rubella during pregnancy?
The risks are greatest in the first trimester where there is a 90% risk of transmission to the foetus if rubella is contracted for the first time. This falls to 20% in weeks 11-16. After week 16 the only main risk would be of deafness.
In the earlier stages, the following may occur: Cataracts Deafness Heart defects IUGR Inflammation of liver, lungs and brain
What are the risks of contracting chicken pox during pregnancy?
If contracted in the first trimester there is no increased risk of spontaneous miscarriage.
However, foetal varicella syndrome may occur and consists of:
Skin scarring
Limb hypoplasia
Neurological abnormalities such as mental retardation, microcephaly
Microphthalmia, cataracts
If contracted between 20-36 weeks the illness usually only presents as shingles in the first few years of the infant’s life. After 36 weeks around half of babies are affected and can develop severe chickenpox.
What is Faget’s sign in Typhoid fever?
The fever of typhoid fever can occur with a relative bradycardia, referred to as Faget’s sign.
What antibiotics are used for Typhoid fever?
Traditionally drugs such as ampicillin and trimethoprim have been used. However, due to the advent of multi-drug resistant cases, azithromycin or fluoroquinolones are now the mainstay of treatment.
List 6 examples of live attenuated vaccines?
Measles, mumps and rubella vaccines (MMR) Oral polio vaccine (OPV) Smallpox vaccine Yellow fever vaccine Chickenpox vaccine Rotavirus vaccine
List 3 examples of inactivated vaccines?
Hepatitis A vaccine
Inactivated polio vaccine (IPV)
Rabies vaccine
List 5 examples of subunit vaccines?
Haemophilus influenzaetype b (Hib) vaccine Hepatitis B vaccine Human papillomavirus (HPV) vaccine Pneumococcal vaccine Meningococcal vaccine
List 2 examples of toxoid vaccines?
Diphtheria toxoid vaccine Tetanus toxoid (TT) vaccine
What is the treatment for Gonorrhoea?
Ceftriaxone, usually in combination with Azithromycin or Doxycycline.
