Browsing by Author "Gebreyes, W. A."
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Item The global one health paradigm: Challenges and opportunities for tackling infectious diseases at the human, animal, and environment interface in low- resource settings(PLOS Neglected Tropical Diseases., 2014) Gebreyes, W. A.; Dupouy-Camet, J.; Newport, M. J.; Oliveira, C. J. B.; Schlesinger, L. S.; Saif, Y. M.; Kariuki, S.; Saif, L. J.; Saville, W.; Wittum, T.; Hoet, A.; Quessy, S.; Kazwala, R.; Tekola, B.; Shryock, T.; Bisesi, M.; Patchanee, P.; Boonmar, S.; King, L. J.Zoonotic infectious diseases have been an important concern to humankind for more than 10,000 years. Today, approximately 75% of newly emerging infectious diseases (EIDs) are zoonoses that result from various anthropogenic, genetic, ecologic, socioeconomic, and climatic factors. These interrelated driving forces make it difficult to predict and to prevent zoonotic EIDs. Although significant improvements in environmental and medical surveillance, clinical diagnostic methods, and medical practices have been achieved in the recent years, zoonotic EIDs remain a major global concern, and such threats are expanding, especially in less developed regions. The current Ebola epidemic in West Africa is an extreme stark reminder of the role animal reservoirs play in public health and reinforces the urgent need for globally operationalizing a One Health approach. The complex nature of zoonotic diseases and the limited resources in developing countries are a reminder that the need for implementation of Global One Health in low-resource settings is crucial. The Veterinary Public Health and Biotechnology (VPH-Biotec) Global Consortium launched the International Congress on Pathogens at the Human-Animal Interface (ICOPHAI) in order to address important challenges and needs for capacity building. The inaugural ICOPHAI (Addis Ababa, Ethiopia, 2011) and the second congress (Porto de Galinhas, Brazil, 2013) were unique opportunities to share and discuss issues related to zoonotic infectious diseases worldwide. In addition to strong scientific reports in eight thematic areas that necessitate One Health implementation, the congress identified four key capacity-building needs: (1) development of adequate science-based risk management policies, (2) skilled-personnel capacity building, (3) accredited veterinary and public health diagnostic laboratories with a shared database, and (4) improved use of existing natural resources and implementation. The aim of this review is to highlight advances in key zoonotic disease areas and the One Health capacity needs.Item In-feed use of heavy metal micronutrients in U.S. Swine production systems and its role in persistence of multidrug-resistant Salmonellae(ASM News- American Society for Microbiology, 2014) Medardus, J. J.; Molla, B. Z.; Nicol, M.; Morrow, W. M.; Rajala-Schultz, P. J.; Kazwala, R.; Gebreyes, W. A.The study aimed to characterize the role of heavy metal micronutrients in swine feed in emergence of heavy-metal-tolerant and multidrug-resistant Salmonella organisms. We conducted a longitudinal study in 36 swine barns over a 2-year period. The feed and fecal levels of Cu2+ and Zn2+ were measured. Salmonella was isolated at early and late finishing. MICs of copper sulfate and zinc chloride were measured using agar dilution. Antimicrobial susceptibility was tested using the Kirby-Bauer method, and 283 isolates were serotyped. We amplified pcoA and czcD genes that encode Cu2+ and Zn2+ tolerance, respectively. Of the 283 isolates, 113 (48%) showed Cu2+ tolerance at 24 mM and 164 (58%) showed Zn2+ tolerance at 8 mM. In multivariate analysis, serotype and source of isolates were significantly associated with Cu2+ tolerance (P < 0.001). Fecal isolates were more likely to be Cu2+ tolerant than those of feed origin (odds ratio [OR], 27.0; 95% confidence interval [CI], 2.8 to 250; P = 0.0042) or environmental origin (OR, 5.8), implying the significance of gastrointestinal selective pressure. Salmonella enterica serotypes Typhimurium and Heidelberg, highly significant for public health, had higher odds of having >20 mM MICs of Cu2+ than did “other” serotypes. More than 60% of Salmonella isolates with resistance type (R-type) AmStTeKm (32 of 53) carried pcoA; only 5% with R-type AmClStSuTe carried this gene. czcD gene carriage was significantly associated with a higher Zn2+ MIC (P < 0.05). The odds of having a high Zn2+ MIC (≥8 mM) were 14.66 times higher in isolates with R-type AmClStSuTe than in those with R-type AmStTeKm (P < 0.05). The findings demonstrate strong association between heavy metal tolerance and antimicrobial resistance, particularly among Salmonella serotypes important in public health.Item Molecular characterization of multidrug resistant salmonella isolates from food animals and animal products in Tanzania(Tanzania Veterinary Journal, 2020) Medardus, J. J.; Gebreyes, W. A.Food animals are major sources of human salmonellosis. Animals raised for food play an important role in transmission of antimicrobial resistant Salmonella strains to humans. The aim of this study was to determine the antimicrobial resistance profile, the occurrence of class 1 integrons and the resistance gene cassettes mobilized in the class 1 integrons of Salmonella isolates. A cross-sectional design was carried out in pastoral regions of Tanzania with large population of livestock. Salmonella isolates were recovered from 4.2% of the total of 1540 samples from apparently healthy animals and the animal products. The results showed that Salmonella isolates were detected in 5.2%, 3.7% and 3.8% of the swine, cattle and chicken, respectively. Sixty-one Salmonella isolates belonged to Salmonella enterica subsp. enterica. Predominant serotypes were Salmonella I 8,20:i:- (32.8%), S. Hadar (10.9%), S. Colindale (6.3%), S. Anatum (6.3%) and S. Heidelberg (6.3%). S. I 8,20:i:- isolates were widespread in different samples from different food animals. Of 64 Salmonella isolates, about 35.9% were resistant to at least one antimicrobial, whereas, 82.6% were multi-drug resistant (MDR) Salmonella. About 8.7% of the MDR Salmonella isolates were found to also carry integrons (intI1) and 100% of intI1-positive isolates contained resistance gene cassettes known as aac(3)-Id-aadA7 showing high rate of MDR. The occurrence of clonal MDR Salmonella isolates in food animals and animal products from pastoral communities indicates the high significance of informal traditional sector as an important source of foodborne pathogens in the food chain and the entry of pathogens to the pastoralist communities.Item Phenotypic and genotypic characterization of salmonella enterica in captive wildlife and exotic animal species in Ohio, USA(Blackwell Verlag GmbH, 2015) Farias, L. F. P.; Oliveira, C. J. B.; Medardus, J. J.; Molla, B. Z.; Wolfe, B. A.; Gebreyes, W. A.The purpose of this study was to investigate the occurrence, antimicrobial resis- tance patterns, phenotypic and genotypic relatedness of Salmonella enterica recovered from captive wildlife host species and in the environment in Ohio, USA. A total of 319 samples including faecal (n = 225), feed (n = 38) and envi- ronmental (n = 56) were collected from 32 different wild and exotic animal spe- cies in captivity and their environment in Ohio. Salmonellae were isolated using conventional culture methods and tested for antimicrobial susceptibility with the Kirby–Bauer disc diffusion method. Salmonella isolates were serotyped, and genotyping was performed using the pulsed-field gel electrophoresis (PFGE). Sal- monella was detected in 56 of 225 (24.9%) faecal samples; six of 56 (10.7%) envi- ronmental samples and six of 38 (15.8%) feed samples. Salmonella was more commonly isolated in faecal samples from giraffes (78.2%; 36/46), cranes (75%; 3/4) and raccoons (75%; 3/4). Salmonella enterica serotypes of known public health significance including S. Typhimurium (64.3%), S. Newport (32.1%) and S. Heidelberg (5.3%) were identified. While the majority of the Salmonella iso- lates were pan-susceptible (88.2%; 60 of 68), multidrug-resistant strains including penta-resistant type, AmStTeKmGm (8.8%; six of 68) were detected. Genotypic diversity was found among S. Typhimurium isolates. The identification of clon- ally related Salmonella isolates from environment and faeces suggests that indirect transmission of Salmonella among hosts via environmental contamination is an important concern to workers, visitors and other wildlife. Results of this study show the diversity of Salmonella serovars and public health implications of human exposure from wildlife reservoirs.Item Role of biocides in occurrence and persistence of biocide-tolerant and multi- drug resistant salmonellae(Tanzania Veterinary Journal, 2020) Medardus, J. J.; Kazwala, R. R.; Gebreyes, W. A.The aim of this study was to characterize the role of biocide interventions in the emergence of biocide-tolerant Salmonella, its co-selective association with multidrug-resistant Salmonella and the association with carriage of specific efflux gene markers. Salmonella isolates were detected in 13.9% (208/1,497) and 6.7% (98/1,468) of swine barn drag swab samples at pre- and post- disinfection with biocide, whereas, Salmonella isolates were detected in 17.2% (1,180/6,842) and 7.1% (431/6,093) of the early and late finishing pigs, respectively. Barn-level prevalence of antimicrobial resistance among Salmonella isolates recovered from the floor swab samples was 92.3% (1,503 of 1,628), whereas, the barn-level prevalence of antimicrobial resistance among Salmonella isolates recovered from the fecal samples was 98.02% (4,415 of 4,504). A total of 348 Salmonella isolates from swine barns formerly disinfected with Biosentry and 428 from swine barns disinfected with Synergize were subjected to minimum inhibitory concentration (MIC) testing for Biosentry and Synergize, respectively. In addition, selected Salmonella isolates were also genotyped to identify the carriage of quaternary ammonium compound (qac) tolerance genes. Interestingly, 22.9% (98 of 428) of Salmonella isolates from swine barns disinfected with Synergize carried the qac gene and the 86% of isolates that carried the qac gene also carried attenuated qacEΔ1. Nearly 31% (109 of 348) of Salmonella isolates from swine barns disinfected with Biosentry carried the qac gene. Furthermore, out of 109 Salmonella isolates that carried qac genes, 94.5% of the isolates contained attenuated qacEΔ1 gene, whereas 72.5% of the isolates carrying qacEΔ1 gene also carried class 1 integrons which is associated with both antibiotic and quaternary ammonium compound resistance. Although biocides are effective in limiting the growth, load and the colonization of bacterial pathogens, this study underscores the contribution of biocides in selective pressure towards antibiotic resistant in Salmonella.Item Role of biocides in occurrence and persistence of biocide-tolerant and multi- drug resistant salmonellae(Tanzania Veterinary Journal, 2020) Medardus, J. J.; Kazwala, R. R.; Gebreyes, W. A.The aim of this study was to characterize the role of biocide interventions in the emergence of biocide-tolerant Salmonella, its co-selective association with multidrug-resistant Salmonella and the association with carriage of specific efflux gene markers. Salmonella isolates were detected in 13.9% (208/1,497) and 6.7% (98/1,468) of swine barn drag swab samples at pre- and post- disinfection with biocide, whereas, Salmonella isolates were detected in 17.2% (1,180/6,842) and 7.1% (431/6,093) of the early and late finishing pigs, respectively. Barn-level prevalence of antimicrobial resistance among Salmonella isolates recovered from the floor swab samples was 92.3% (1,503 of 1,628), whereas, the barn-level prevalence of antimicrobial resistance among Salmonella isolates recovered from the fecal samples was 98.02% (4,415 of 4,504). A total of 348 Salmonella isolates from swine barns formerly disinfected with Biosentry and 428 from swine barns disinfected with Synergize were subjected to minimum inhibitory concentration (MIC) testing for Biosentry and Synergize, respectively. In addition, selected Salmonella isolates were also genotyped to identify the carriage of quaternary ammonium compound (qac) tolerance genes. Interestingly, 22.9% (98 of 428) of Salmonella isolates from swine barns disinfected with Synergize carried the qac gene and the 86% of isolates that carried the qac gene also carried attenuated qacEΔ1. Nearly 31% (109 of 348) of Salmonella isolates from swine barns disinfected with Biosentry carried the qac gene. Furthermore, out of 109 Salmonella isolates that carried qac genes, 94.5% of the isolates contained attenuated qacEΔ1 gene, whereas 72.5% of the isolates carrying qacEΔ1 gene also carried class 1 integrons which is associated with both antibiotic and quaternary ammonium compound resistance. Although biocides are effective in limiting the growth, load and the colonization of bacterial pathogens, this study underscores the contribution of biocides in selective pressure towards antibiotic resistant in Salmonella.Item Supplementation with quaternary benzo(c)phenanthridine alkaloids decreased salivary cortisol and salmonella shedding in pigs after transportation to the slaughterhouse(Mary Ann Liebert, Inc., 2015) Artuso-Ponte, V.; Moeller, S.; Rajala-Schultz, P.; Medardus, J. J.; Munyalo, J.; Lim, K.; Gebreyes, W. A.The present study was aimed at evaluating the effect of herbal extracts supplementation, particularly quaternary-benzo(c)phenanthridine alkaloids (QBA), which have been previously demonstrated to have anti- inflammatory, antimicrobial, and immune-modulator effects. We investigated the role of QBA on stress re- sponse and Salmonella shedding in finishing pigs transported to the slaughterhouse. A total of 82 pigs were orally challenged with a Salmonella cocktail (day 0) containing Salmonella Meleagridis, Hartford, Bo- vismorbificans and Newport serovars and randomly assigned to three treatment groups after 2 wks (day [D] 14): T1, in-feed QBA; T2, in-feed and water-soluble QBA; CON, nonsupplemented). Pigs were transported to the slaughterhouse 2 weeks after intervention (D 28) and slaughtered after nearly 19 h (D 29). Saliva, fecal samples, and carcass swabs were collected from all pigs. Salivary cortisol, Salmonella shedding, and carcass contami- nation were measured. A high positive correlation (Spearman rank correlation coefficient range 0.82–0.93) between salivary cortisol and Salmonella shedding was found after transportation in all groups ( p < 0.05). Only the CON group showed an increase in salivary cortisol after transportation (5.48 ng/mL; p < 0.0001) to con- centrations that were higher than in T1 (2.73 ng/mL; p = 0.0002) and T2 (1.88 ng/mL; p < 0.0001). Salmonella prevalence and shedding decreased after transportation in pigs receiving the QBA intervention ( p < 0.05), whereas the control group showed a significant increase in Salmonella shedding after transportation ( p = 0.04). At D 28, pigs in T2 shed lower numbers of Salmonella as compared to T1 (1.3E + 02 CFU/mL versus 8E + 03 CFU/mL; p = 0.002). Additionally, carcass contamination by Salmonella was higher in the CON group than the treated groups ( p = 0.01). The findings show QBA intervention was effective in reducing transportation stress of pigs, resulting in reduced Salmonella shedding and positively impacting animal welfare and pork safety.