Veterinary Medicine

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Author: search.filters.author.Amosun, E. A.

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    Multidrug resistant verocytotoxin-producing Escherichia coli O157:H7 in the faeces of diarrhoeic and non-diarrhoeic dogs in Abeokuta, Nigeria
    (Faculty of Veterinary Medicine, University of Zagreb, 2014) Ojo, O. E.; Bello, A. O.; Amosun, E. A.; Ajadi, R. A.
    Verocytotoxin-producing Escherichia coli (VTEC) 0157:H7 is a predominant cause of haemorrhagic colitis (HC) and haemolytic uraemic syndrome (HUS) in humans. To assess thè role of dogs as a possible source oftransmission ofVTEC 0157:H7 to humans, thè faeces of diarrhoeic (31) and non-diarrhoeic (63) dogs were examined for thè presence of thè organista. Escherichia coli 0157:H7 was isolated from 22 (23.4%) out of 94 samples examined. The organism was detected in 5 (16.1%) out of 31 diarrhoeic faeces and 17 (26.9%) out of 63 non-diarrhoeic faeces, but thè difference was not statistically significant (P>0.05). All thè E. coli 0157:H7 isolates produced one or both of verocytotoxin 1 and 2 (VT1 and VT2). Verocytotoxin 1 (VT1) was detected in 10 (45.5%) out of 22 isolates, VT2 in 8 (36.4%), while both toxin types were detected in four (18.2%) isolates. Sixteen (72.7%) out of 22 isolates were resistant to at least three antimicrobials from different classes, while 18 distinct antimicrobial resistance pattems were observed among thè isolates. The isolates showed resistance to ampicillin (86.4%), chloramphenicol (36.4%), ciprofloxacin (4.5%), gentamicin (18.2%), kanamycin (68.2%), nalidixic acid (22.7%), neomycin (40.9%), norfloxacin (9.1%), streptomycin (63.6%), sulphamethoxazole/ trimethoprim (63.6%) and tetracycline (77.3%). The present study showed that diarrhoeic and non-diarrhoeic dogs may serve as potential sources of multi-drug resistant VTEC 0157 :H7 transmissible to humans.
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    Multidrug resistant verocytotoxin-producing Escherichia coli O157:H7 in the faeces of diarrhoeic and non-diarrhoeic dogs in Abeokuta, Nigeria
    (Faculty of Veterinary Medicine, University of Zagreb, 2014) Ojo, O. E.; Bello, A. O.; Amosun, E. A.; Ajadi, R. A.
    Verocytotoxin-producing Escherichia coli (VTEC) 0157:H7 is a predominant cause of haemorrhagic colitis (HC) and haemolytic uraemic syndrome (HUS) in humans. To assess thè role of dogs as a possible source oftransmission ofVTEC 0157:H7 to humans, thè faeces of diarrhoeic (31) and non-diarrhoeic (63) dogs were examined for thè presence of thè organista. Escherichia coli 0157:H7 was isolated from 22 (23.4%) out of 94 samples examined. The organism was detected in 5 (16.1%) out of 31 diarrhoeic faeces and 17 (26.9%) out of 63 non-diarrhoeic faeces, but thè difference was not statistically significant (P>0.05). All thè E. coli 0157:H7 isolates produced one or both of verocytotoxin 1 and 2 (VT1 and VT2). Verocytotoxin 1 (VT1) was detected in 10 (45.5%) out of 22 isolates, VT2 in 8 (36.4%), while both toxin types were detected in four (18.2%) isolates. Sixteen (72.7%) out of 22 isolates were resistant to at least three antimicrobials from different classes, while 18 distinct antimicrobial resistance pattems were observed among thè isolates. The isolates showed resistance to ampicillin (86.4%), chloramphenicol (36.4%), ciprofloxacin (4.5%), gentamicin (18.2%), kanamycin (68.2%), nalidixic acid (22.7%), neomycin (40.9%), norfloxacin (9.1%), streptomycin (63.6%), sulphamethoxazole/ trimethoprim (63.6%) and tetracycline (77.3%). The present study showed that diarrhoeic and non-diarrhoeic dogs may serve as potential sources of multi-drug resistant VTEC 0157 :H7 transmissible to humans.
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    The comparative susceptibility of commercial and Nigerian indigenous chicken ecotypes to Salmonella gallinarum infection
    (Faculty of Veterinary Medicine, Usmanu Danfodiyo University, Sokoto, Nigeria, 2013) Ogie, A. J.; Salako, A. E.; Emikpe, B. O.; Amosun, E. A.; Adeyemo, S. A.; Akinoluwa, P. O.
    This study was to evaluate thè possible genetic resistance of exotic and indigenous chicks to Salmonella gallinarum. A total of 72 nine weeks-old chicks were used for thè study. The Fulani ecotype (Fulani smooth feathers - FSF), Yoruba ecotype (Yoruba smooth feathers - YSF), and thè Exotic breed (Nera Black) chicks were infected with a dose of S. gallinarum (8.3 x IO6 CFU) and were observed for 16 days. Evaluation of resistance was based on clinical signs, mortality, pathology, leukocyte count, bacterial count from liver and spleen of infected chicks. The highest peak for clinical signs in 5. gallinarum infected chicks coincides with highest mortalities recorded on day 11-12 dpi and bacterial count of both liver and spleen on day 8. The lymphocytes count declined on day 8 for all thè experimental chicks except for thè exotic breed. There was no significant difference between thè bacterial counts of thè different groups on day 8. In S. gallinarum infected chicks, 94.4% of all thè chicks showed clinical signs after infection, thè exotic breed showed a prolonged clinical signs while thè Yoruba ecotype showed thè least. 87.5%, 80.0% and 37.5% mortality were recorded in thè exotic breed, Fulani and Yoruba ecotypes respectively. The study showed that thè exotic chicken (Nera Black) was more susceptible to Salmonella gallinarum infection. It also indicated that within thè ecotypes in Nigeria, Fulani ecotype was more susceptible to Salmonella gallinarum infection than thè Yoruba ecotype. The lower clinical signs and mortality observed in Yoruba ecotype indicated a resistance of thè ecotype to 5. gallinarum infection.
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    Escherichia coli from Nigeria exhibit a high prevalence of antibiotic resistance where reliance on antibiotics in poultry production is a potential contributing factor
    (Academic Journals, 2013) Nsofor, C. A.; Olatoye, I. O.; Amosun, E. A.; Iroegbu, C. U.; Davis, M. A.; Orfe, L. H.; Cali, D. R.
    To assess thè prevalence of antibiotic resistance in Nigeria, single Escherichia coli isolates were collected from a geographically diverse panel of fecal samples collected from human clinical and non- clinical donors (n=77), livestock (cattle, swine, and goats) and chickens (n=71 total). There was no difference in thè proportion of isolates resistant to >1 antibiotics from human clinical and non-clinical samples, but overall, this was significantly higher for human (85.7%) compared to animai (53.5%) isolates (P<0.0001). The average number of resistance phenotypes per isolate was significantly higher for human (5.0), goat (4.0), and poultry (3.4) compared with cattle (2.4) and swine (2.0) (P<0.05). There were 25 different resistance phenotypes with more diversity from animai compared with human isolates. A survey of management practices at 30 poultry farms in thè vicinity of Ibadan found that all respondents self-milled feed and most (87.7%) routinely added antibiotics to feed. Tetracyclines were thè dominant antibiotics of choice followed by tylosin and gentamicin and some use of chloramphenicol, ciprofloxacin, and enrofloxacin. If this pattern of antibiotic resistance and use is repeated across thè different sectors of food-animal production and in multiple developing countries, then trade and travel are likely to disseminate resistance traits to other countries potentially negating locai policies that are designed to limit selection for antibiotic resistant bacteria
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    The possible genetic influence on the susceptibility of exotic, Fulani, and Yoruba ecotype indigenous chickens to experimental Salmonella enteritidis
    (Fundación CIPAV, Cali, Colombia, 2012) Ogie, A. J.; Salako, A. E.; Emikpe, B. O.; Amosun, E. A.; Adeyemo, S. A.; Toyosi, O. A
    This study was conducted to evaluate the possible genetic resistance of exotic and indigenous chicks to Salmonella enteritidis. A total of 72 9 weeks old chicks were for this study which include the Fulani ecotype (FSF), Yoruba ecotype (YSF), and the Exotic breed (Black Nera cockerel). Chicks were infected with 3.8 x104 CFU of S. enteritidis and were observed for 16 days. Evaluation of possible genetic resistance was based on clinical signs, mortality and differential leukocytes count of infected chicks. Clinical signs were evident on day 3 with eighty three percent (83.3%) of the chicks showing severe clinical signs on day 8 post infection. The exotic breed had the most prolonged clinical signs with all the chicks showing severe clinical signs. Yoruba ecotype had the shortest timing for the clinical signs, with 62.5% of the Yoruba ecotype affected. 87.5% of the Fulani ecotype and 98% of the exotic breed were affected. No mortality was recorded with the chicks infected with S. enteritidis. Assessing the clinical signs observed from infected chicks revealed that Yoruba ecotype is the least susceptible. The result from the study also indicated that the exotic is more susceptible to Salmonella infection than the indigenous chicks. It also revealed that within the ecotypes in Nigeria, Fulani ecotype is more susceptible to Salmonella infection than the Yoruba ecotype. The differential susceptibility and the low mortality observed in Yoruba ecotype indicated probable genetic resistance to S. enteritidis
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    Multidrug-resistant Escherichia coli O157 contamination of beef and chicken in municipal abattoirs of Southwest Nigeria
    (Marsland Press (East Lansing, Michigan), 2012) Olatoye, I. O.; Amosun, E. A.; Ogundipe, G. A. T.
    Indiscriminate antibiotics usage in food animals and unhygienic meat processing could predispose meat consumers to risks of antibiotic resistant bacterial contamination and infection. This study investigated thè contamination of meat ffom cattle and chicken slaughtered for human consumption with E. coli 0157:H7 at thè metropolitan abattoirs and slaughtered slabs of selected poultry farms in Lagos and Ibadan, Nigeria. The aim was to compare thè prevalence and antibiotic susceptibility pattems across thè different locations and climatic seasons. The organism was isolated by cultural method using selective media and confirmed serologically using latex agglutination kits (OxoidR IJK). Antibiotic susceptibility to ten antimicrobial agents was performed by disc diffiision method using commercial Grana negative discs. Out of 800 meat samples collected, thè overall prevalence of 17.1% (comprising of 19.8% and 14.5% of beef and chicken respectively) was obtained. The prevalence of E. coli 0157:H7 in beef ffom Ibadan and Lagos were 28.5% and 11.0%, while those of chicken from Ibadan and Lagos markets were 13.0% and 14.0%, and ffom Ibadan and Lagos farms were 18.0% and 13.0% respectively. The prevalence of E. coli 0157 was significantly higher in beef compared to chicken (p<0.05), while during wet season, contamination of beef was also higher than in dry and significantly higher in beef from Ibadan than Lagos abattoir. All thè isolates were resistant to one or multiple antibiotics, but thè highest resistance of 91.1 % was to tetracycline and nine different resistance pattems were observed among thè isolates. Indiscriminate antibiotics usage in livestock predisposes meat consumers to risks of antibiotic resistant Escherichia coli 0157:H7 in Southwest Nigeria. Regulatory control of antibiotics usage in livestock production, meat hygiene and pharmaco-epidemiological surveillance in food animals is hereby recommended to ensure consumer safety
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    Antimicrobial Resistance in Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa Isolated from the Milk of Dairy Cows in Three Nigerian Cities
    (Nigerian Veterinary Medical Association, 2012) Amosun, E. A.; Olatoye, O. I.; Adetosoye, A. I
    Bovine mastitis is usually associated with bacterial pathogens isolated from the milk or mammary glands of dairy cows. A total of 205 isolates comprising of 110 (53.66%) Escherichia coli, 67 (32.68%) Klebsiella pneumoniae, and 28 (13.66%) Pseudomonas aeruginosa obtained from cases of bovine mastitis from southwest and Northern Nigeria during a period of one year were tested for susceptibility to ampicillin, tetracycline, neomycin, streptomycin, sulphadimidine and nalidixic acid using minimum inhibitory concentration (MIC) method. The results demonstrated wide variation of in the susceptibility patterns for the various organisms from different regions of Nigeria. The three organisms displayed highest resistance to sulphadimidine 200 (97.5%) followed by ampicillin 153 (74.63%), tetracycline 103 (50.24%), neomycin 90 (43.90%), streptomycin 68 (33.17%) and nalidixic acid 29 (14.15%) respectively. The resistance patterns of the strains revealed 27 distinct resistance groups. In conclusion these data confirmed that majority of the Gram negative organisms that are causative agents of mastitis in Nigeria were resistant to several antibiotics. This could be a result of indiscriminate use of drugs by dairy farmers for treatment of mastitis in their herds.
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    Antimicrobial Resistance in Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa Isolated from the Milk of Dairy Cows in Three Nigerian Cities
    (Nigerian Veterinary Medical Association, 2012) Amosun, E. A.; Olatoye, O. I.; Adetosoye, A. I.
    This study determined the safety of milk from dairy herds obtained by hand milking method from two major cattle producing States of Nigeria by investigating the presence of Escherichia coli 0157:H7 and their antibiotic susceptibility pattern. Forty seven milk samples from Kwara and 63 from Kaduna States were obtained from selected indigenous breeds of dairy cow. Bacteriological analysis by culturing on MacConkey agar (MAC) and subcultured on Sorbitol MacConkey agar (SMAC) were done. Escherichia coli 0157.H7 were confirmed serologically using latex agglutination kits (OxoidR UK). The isolates were tested for susceptibility to five commonly used antimicrobial agents and plasmid transfer was also carried out using E. coli K12 356 recipient. Out of the 61 non-Sorbitol fermenting (NSF) E. coli isolated from the samples 33(30.0%) were confirmed as E .coli 0157.H7 serotype. Antibiotic Susceptibility profile showed that all the isolates were resistant to one or multiple antibiotics, resulting in six different resistance patterns. Sulphadimidine resistance was the highest with all the isolates (100%) exhibited resistance to this drug while streptomycin had the highest sensitivity. Out of the seventeen E.coli 0157.H7 isolates tested for plasmid transfer, eleven (64.7%) transferred their resistance to the sensitive E. coli K12 356 enblock, while the remaining six showed segregation. The preponderance of E. coli O157 in this study indicated that greater proportion of milk being produced for human consumption in Nigeria were not wholesome and could posed threat of transmission of zoonotic pathogens. The high proportion of multidrug resistance exhibited by the isolates and the plasmid transfer is of public health significance as they could confer resistance on both pathogenic and non-pathogenic bacterial population in the consumers. More so, the milk which were obtained traditional unhygienic hand milking are either consumed raw or improperly pasteurized. Hygienic milking, pasteurization and judicious use of antibiotics after properly diagnosis and sensitivity test against newer antibiotics are recommended.
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    Isolation and antibiotics susceptibility patterns of Escherichia Coli O157:H7 from selected dairy herds in Nigeria
    (African Union, InterAfrican Bureau for Animal Resources (AU-IBAR), 2012) Amosun, E. A.; Olatoye, I. O.; Adetosoye, I. A.
    This study determined the safety of milk from dairy herds obtained by hand milking method from two major cattle producing States of Nigeria by investigating the presence of Escherichia coli 0157:H7 and their antibiotic susceptibility pattern. Forty seven milk samples from Kwara and 63 from Kaduna States were obtained from selected indigenous breeds of dairy cow. Bacteriological analysis by culturing on MacConkey agar (MAC) and subcultured on Sorbitol MacConkey agar (SMAC) were done. Escherichia coli 0157.H7 were confirmed serologically using latex agglutination kits (OxoidR UK). The isolates were tested for susceptibility to five commonly used antimicrobial agents and plasmid transfer was also carried out using E. coli K12 356 recipient. Out of the 61 non-Sorbitol fermenting (NSF) E. coli isolated from the samples 33(30.0%) were confirmed as E .coli 0157.H7 serotype. Antibiotic Susceptibility profile showed that all the isolates were resistant to one or multiple antibiotics, resulting in six different resistance patterns. Sulphadimidine resistance was the highest with all the isolates (100%) exhibited resistance to this drug while streptomycin had the highest sensitivity. Out of the seventeen E.coli 0157.H7 isolates tested for plasmid transfer, eleven (64.7%) transferred their resistance to the sensitive E. coli K12 356 enblock, while the remaining six showed segregation. The preponderance of E. coli O157 in this study indicated that greater proportion of milk being produced for human consumption in Nigeria were not wholesome and could posed threat of transmission of zoonotic pathogens. The high proportion of multidrug resistance exhibited by the isolates and the plasmid transfer is of public health significance as they could confer resistance on both pathogenic and non-pathogenic bacterial population in the consumers. More so, the milk which were obtained traditional unhygienic hand milking are either consumed raw or improperly pasteurized. Hygienic milking, pasteurization and judicious use of antibiotics after properly diagnosis and sensitivity test against newer antibiotics are recommended.
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    Antimicrobial resistance among commensal Escherichia coli from cattle faeces and beef in Ibadan, Nigeria
    (Academic Journals, 2012) Amosun, E. A.; Ojo, O. E.; Alao, I. K.; Ajuwape, A. T. P.
    Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained from 382 samples. Isolation rate of E. coli was 90.0% in on-farm cattle, 87.1% in slaughter cattle and 92.2% in beef. Overall, the isolates showed resistance to amoxicillin (97.9%), ampicillin (97.9%), cefuroxime (25.1%), chloramphenicol (69.3%), ciprofloxacin (11.7%), cotrimazole (45.9%), erythromycin (59.4%), gentamycin (36.5%), nalidixic acid (27.2%), nitrofuratoin (54.9%), norfloxacin (21.1%), ofloxacin (14.0%), streptomycin (78.9%) and tetracycline (33.9%). There were no significant differences in antimicrobial resistance of E. coli from the different sample types. Only four (1.2%) of the 342 isolates were susceptible to all antimicrobial agents, while 338 (98.8%) were resistant to at least one of the tested antimicrobial agents. Multi-drug resistance to three or more antimicrobials was observed in 321 (93.9%) of all the isolates. Forty-one resistance groups were observed in on-farm cattle, 30 in slaughter cattle and 34 in beef. All the 30 resistance groups found in slaughter cattle were also present in on-farm cattle and beef. ‘AmoAmpChlEryNitStr’ and ‘AmoAmpChlStr’ were the predominant resistant patterns. This study confirmed on-farm and slaughter cattle as important sources of antimicrobial resistant E. coli transmissible to humans through beef.