Isolation and identification of E-coli 0157:H7 amongst Sudanese patients with bloody diarrhea and in animals

E.coli 0157:H7 is present as a commensal in the intestine of animals and as a pathogen in human beings. It causes bloody diarrhoea due to the secretion of a verotoxin which may lead to lethal complications.Objective: This study is aimed at determining the presence of this organism in animals and patients. Methods: Rectal swabs were collected from 250 cows. Stool specimens were obtained from 200patients presenting with macroscopically or microscopically bloody diarrhoea. All specimens were cultured on sorbitol MacConkey agar and incubated at 37°C overnight. Non-sorbitol fermenting colonies were identified by different biochemical and serological tests as E.coli 0157:H7. Antibiotic sensitivity was done for the isolates using ampicillin, cephalexin, ciprofloxacin, co-trimoxazole, gentamicin, and tetracycline. Results: Patients (n = 10, 5%) with bloody diarrhoea were found to harbour E.coli 0157:H7 in their stools. All isolates (in humans) were resistant to ampicillin. Eight (80%) were resistant to tetracycline and cephalexin, six (60%) to co-trimoxazole, and four (40%) to gentamicin. All isolates were sensitive to ciprofloxacin. Sixty percent of the human isolates were resistant to three antibiotics and 40% to four antibiotics. Twenty of the cows (8%) were found to be carriers of E.coli0157:H7. All isolates (in animals) were resistant to ampicillin, five (25%) to tetracycline and cephalexin and four (20%) to co-trimoxazole. All animal isolates were sensitive to gentamicin and ciprofloxacin. Thirty five percent of the animal isolates were resistant to two antibiotics and 25% to three antibiotics. Conclusion: The isolation of E.coli 0157:H7 from animals and patients should direct the attentionof physicians and paediatricians to consider the possibility of infection and complications by this organism.Key words: Antibiotic sensitivity, sorbitol MacConkey agar, serological tests

Molecular Identification of Methicillin-Resistant Staphylococcus aureus in Khartoum Teaching Hospital

Antimicrobial resistance has become a great public health problem worldwide and multi-drug resistant Staphylococcus aureus has been widely reported.Methods: The presence or absence of methicillin resistance gene (mecA) in 48 clinical wound isolates of S. aureus was examined by the polymerase chain reaction (PCR). The results were analyzed in parallel to the disk diffusion method by oxacillin (1 μg). Polymerase chain reaction was amplified at a sequence of mecA gene at 1319 bp.Results: Nine (18.75%) out of the 48 isolates and were found to be identical to those of disk diffusion test. All strains were studied for their susceptibility to traditionally used antibiotics. The results revealed that multi-drug resistance was common among MRSA strains. The drug of choice for the treatment of MRSA and MSSA was vancomycin.Conclusion: The study concluded that multiple antibiotic resistance was common, and the PCR assay can be used to confirm MRSA infection.Key words: MRSA, polymerase chain reaction (PCR)

The use of antibiotics as food additives in poultry and their effect on antibiotic resistance

The widespread use and misuse of antimicrobials beyond human medicine, assisted in the alarming emergence of resistance amongst the bacterial strains. Aim: to determine the effect of the use of antibiotics as food additives on the intestinal flora of poultry.Methods: one hundred and eighty chickens at the age of two weeks were divided equally into six groups. Five of these groups were used for the test and the sixth served as a control group. Each of the test groups was fed with a different type of antibiotic which served as food additives. The control group was fed an antibiotic-free diet. The antibiotics used were amoxycillin, ciprofloxacin, tetracycline, gentamicin and co-trimoxazole. Rectal swabs were collected from the chickens at the age of two and six weeks respectively. The specimens were processed for the isolation and antibiotic sensitivity of E. coli from each group. After slaughtering the chickens, the presence of the antibiotic residue in the tissues was tested. Pieces of tissues were applied on a sensitivity agar using standard E coli as a test organism. Results: significant increase in antibiotic resistance was noticed in the test groups (P 0.05). The pieces of tissues from the test groups inhibited the growth of E coli indicating the presence of antibiotic residue. No inhibition of growth was detected in the control group. Conclusion: the use of antibiotics as food additives in animals and poultry can lead to the emergence of resistant bacterial strains in their intestinal flora and can leave antibiotic residue in their tissue.Key words: Antibiotics, Food additives, Poultry