Browsing by Author "Olsen, John E."

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First Report on a Randomized Investigation of Antimicrobial Resistance in Fecal Indicator Bacteria from Livestock, Poultry, and Humans in Tanzania
(Mary Ann Liebert, Inc., 2018-04-01) Katakweba, Abdul A. S.; Muhairwa, Amandus P.; Lupindu, Athumani M.; Damborg, Peter; Rosenkrantz, Jesper T.; Minga, Uswege M.; Mtambo, Madundo M. A.; Olsen, John E.
This study provides an estimate of antimicrobial resistance in intestinal indicator bacteria from humans (n = 97) and food animals (n = 388) in Tanzania. More than 70% of all fecal samples contained tetracycline (TE), sulfamethoxazole (STX), and ampicillin (AMP)-resistant coliforms, while cefotaxime (CTX)-resistant coliforms were observed in 40% of all samples. The average Log10 colony forming units/g of CTX-resistant coliforms in samples from humans were 2.20. Of 390 Escherichia coli tested, 66.4% were resistant to TE, 54.9% to STX, 54.9% to streptomycin, and 36.4% to CTX. Isolates were commonly (65.1%) multiresistant. All CTX-resistant isolates contained blaCTX-M gene type. AMP- and vancomycin-resistant enterococci were rare, and the average concentrations in positive samples were low (log10 0.9 and 0.4, respectively). A low-tomoderate resistance (2.1–15%) was detected in 240 enterococci isolates to the drugs tested, except for rifampicin resistance (75.2% of isolates). The average number of sulII gene copies varied between Log10 5.37 and 5.68 with no significant difference between sample source, while cattle had significantly higher number of tetW genes than humans. These findings, based on randomly obtained samples, will be instrumental in designing antimicrobial resistance (AMR) intervention strategies for Tanzania.
Isolation of vancomycin‐resistant Enterococcus from apparently healthy human animal attendants, cattle and cattle wastes in Tanzania
(Wiley Online Library, 2018-05) Madoshi, Balichene P.; Mtambo, Mtambo M. A; Muhairwa, Amandus P.; Lupindu, Athumani M.; Olsen, John E.
Aim: The study aimed to isolate and characterize Enterococcus species from apparently healthy waste attendants, cattle and cattle waste in Tanzania. Emphasis was given to antimicrobial resistance and in particular occurrence of vancomycin (VA)-resistant enterococci. Methods and Results: Faecal samples were collected from healthy cattle, cattle waste attendants and cattle house wastes, and isolation of Enterococcus species was performed using Slanetz Bartley agar. Isolates were characterized with regard to species, antimicrobial susceptibility and presence of VA resistance genes. Enterococcus faecalis was the most prevalent species from all sources of isolation (43 5%), followed by Enterococcus faecium (38 4%). Isolates of E. faecium showed a higher number of phenotypic antimicrobial resistance than isolates of E. faecalis. Fifty-eight isolates, which showed resistance or intermediate resistance to VA by disc diffusion test, were analysed for VAresistant Enterococcus (VRE) by PCR. The vanA gene was detected in 14 isolates of E. faecium and 12 isolates of E. faecalis, while vanB was detected in three isolates. No isolates were found to carry vanC1-gene. Conclusion: VRE was detected in both human and cattle samples, despite no known use of antimicrobial agents that can select for VRE in livestock in Tanzania. Enterococcus faecalis was the most commonly isolated species from cattle and humans. Significance and Impact of the Study: The study provides information on the prevalence of VRE in human and nonhuman samples in Tanzania calling for further studies on the origin of VRE in such isolates, since no selection mechanism in Tanzania are known.