University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

243

Pages:

2
Author:

Mariam A. A.

• • • • • Bowel bacterial overgrowth Associated with small intestinal stasis caused by: o Anatomic abnormalities o Abnormal small intestinal motility Abnormal communication between the proximal and distal GIT → fistula Multi-factorial causes Consequences o Epithelial cell injury and inflammation o Production of toxins ▪ Elevated ammonia levels ▪ Bacterial production of lactic acid ▪ Bacterial endotoxin effects o Impaired absorption of nutrients ▪ Fats, carbohydrates, proteins, vitamin B12 Symptoms o Abdominal distension, flatulence o Diarrhoea, weight loss o Anaemia o Steatorrhea, vitamin deficiency o Immune dysregulation e.g. reactive arthritis Effects of antibiotics on the bowel • Mild diarrhoea while taking antibiotics or shortly after • More severe colitis associated with overgrowth of an anaerobe – Clostridium difficile • Hospital-acquired infections with antibiotic resistance organisms o Multi-resistant organisms (MROs) ▪ MRSA, VRE, C. difficile, ESBL, MBL • MRSA: methicillin-resistant Staphylococcus aureus • VRE: vancomycin-resistant enterococci • Antibiotic resistant Gram-negative organisms o Meropenem-resistant Acinetobacterbaumanii (MRAB) o Extended-spectrumβ-lactamase (ESBL) o Metallo-β-lactamase(MBL) ▪ 2011 German E. coli outbreak • Antibiotics and MROs o Broad spectrum antibiotics destroy sensitive normal flora on mucosal surfaces → only antibiotic resistant bugs survive o Colonisation with MROs from the hospital environment ▪ Invasive infections ▪ Spread to other mucosal surfaces e.g. respiratory, genital tract ▪ Contamination of environment especially if diarrhoea is present ▪ Contamination of healthcare staff hands and spread to other patients Hospital acquired infections German E. coli (O104:H4) outbreak • Causes bloody diarrhoea → can be lethal (40 deaths) • Haemolytic uraemic syndrome (HUS) o Disease affecting the kidneys • Enterohaemorrhagic E.coli (EHEC) • Enteroaggregative E.coli (EAEC) o EAEC that acquired a virus with a toxin gene ▪ Shiga toxin 2a → kidneys • Resistant to most antibiotics Surgery risks • Surgery when the bowel lumen is open → risk of contamination o Large number of bacteria in operating field o Unless prophylactic antibiotics are given at the time of the surgery, a wound infection is inevitable Keeping the intestinal flora healthy • Probiotics o Microorganisms that have beneficial effects for the host o Mainly derived from food, especially cultured milk production o Efficacy claimed for a range of conditions but no proof for most claims ▪ Possibly useful in antibiotic-associated diarrhoea including that due to C. difficile