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Tadesse B, Ali DA. Prevalence and antimicrobial resistance of salmonellae isolated from eggs of local chicken in selected towns of Ethiopia. Vet Med Sci 2024; 10:e1529. [PMID: 38946179 PMCID: PMC11215156 DOI: 10.1002/vms3.1529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/09/2024] [Accepted: 06/10/2024] [Indexed: 07/02/2024] Open
Abstract
BACKGROUND Salmonellosis is one of the most common food-borne diseases in industrialised and developing countries. In recent year, an increase in antimicrobial resistance among different Salmonella serotypes has been observed. OBJECTIVE A cross-sectional study was conducted to assess the prevalence and antimicrobial susceptibility of Salmonella isolated from local chicken eggs in four selected towns in Ethiopia. METHODS A total of 115 eggs were examined to detect Salmonella by using standard microbiological methods. The susceptibilities of the isolates to nine antimicrobials were tested by the Kirby-Bauer disk diffusion method. RESULT The study revealed that of the 115 eggs examined, 22 (19.1%) were positive for Salmonella of which 14 (12.2%) and 8 (7%) of the isolates were from shells and contents, respectively. The occurrence of Salmonella in egg shells and content and between different altitudes did not differ significantly (p > 0.05). Most isolates were resistant to more than three antimicrobials with a high resistance to kanamycin, ampicillin, nalidixic acid, cotrimoxazole, oxytetracycline and chloramphenicol. CONCLUSION The results indicate the potential importance of local chicken eggs as source of multiple antimicrobial-resistant salmonellae and the need for proper cooking before consumption. Further studies are required to describe the epidemiology of Salmonella in various agroclimatic zones of Ethiopia.
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Affiliation(s)
- Belege Tadesse
- Department of Veterinary MedicineSchool of Veterinary MedicineWollo UniversityDessieEthiopia
| | - Destaw Asfaw Ali
- Department of pathophysiologyCollege of Veterinary Medicine and Animal SciencesUniversity of GondarGondarEthiopia
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Chen K, Li L, Zhou Z, Wang N, Dai C, Sun D, Li J, Xu C, Liao M, Zhang J. BolA promotes the generation of multicellular behavior in S. Typhimurium by regulating the c-di-GMP pathway genes yeaJ and yhjH. Int J Food Microbiol 2024; 411:110518. [PMID: 38101189 DOI: 10.1016/j.ijfoodmicro.2023.110518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 11/14/2023] [Accepted: 12/05/2023] [Indexed: 12/17/2023]
Abstract
The generation of multicellular behavior enhances the stress adaptability, antibiotic resistance, and pathogenic potential of Salmonella enterica serovar Typhimurium (S. Typhimurium), which is challenging for its prevention and control. Therefore, determination of the mechanism of multicellular behavior development is urgently required. Accordingly, this study investigated BolA, a transcription factor that promotes bacterial survival under different stresses. We found that BolA promoted the generation of multicellular behavior. Furthermore, transcriptome analysis revealed that BolA affected the expression of numerous genes, including biofilm formation and motility-related genes. In terms of biofilm formation, compared with the wild-type strain, bolA overexpression (269BolA+) increased the extracellular matrix content (extracellular polysaccharide, extracellular protein, and extracellular DNA (eDNA) by upregulating gene expression, ultimately increasing the biofilm formation ability by 2.56 times. For motility, bolA overexpression inhibited the expression of flagella synthesis genes, resulting in a 91.15 % decrease in motility compared with the wild-type (6 h). Further mechanistic analysis demonstrated that BolA affected the expression of the C-di-GMP pathway genes yeaJ and yhjH, which influenced the generation of multicellular behavior. In terms of biofilms, the extracellular polysaccharide content of 269BolA + ∆Yeaj (bolA overexpression and yeaJ deletion) was reduced by 89.91 % compared with 269BolA+, resulting in a 71.1 % reduction in biofilm forming ability. The motility of the 269∆BolA∆Yhjh (bolA/yhjH double deletion) strain was significantly decreased compared with that of 269∆BolA. Finally, the LacZ gene reporting showed that BolA promoted and inhibited the expression of yeaJ and yhjH, respectively. In conclusion, BolA mainly improves the content of extracellular polysaccharide by promoting the expression of yeaJ, thus enhancing the formation of biofilms. BolA also restricts flagellar synthesis by inhibiting yhjH expression, therefore reducing motility, ultimately promoting multicellular behavior arises. These findings lay a theoretical foundation for the prevention and control of S. Typhimurium.
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Affiliation(s)
- Kaifeng Chen
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Lili Li
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Zhouping Zhou
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Nanwei Wang
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Changzhi Dai
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Dage Sun
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Jiayi Li
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Chenggang Xu
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Ming Liao
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
| | - Jianmin Zhang
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.
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Chen K, Gao Y, Li L, Zhang W, Li J, Zhou Z, He H, Chen Z, Liao M, Zhang J. Increased Drug Resistance and Biofilm Formation Ability in ST34-Type Salmonella Typhimurium Exhibiting Multicellular Behavior in China. Front Microbiol 2022; 13:876500. [PMID: 35369456 PMCID: PMC8972162 DOI: 10.3389/fmicb.2022.876500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 02/28/2022] [Indexed: 11/29/2022] Open
Abstract
Salmonella Typhimurium is an important food-borne pathogen. In this paper, multicellular behavior and associated characteristics of S. Typhimurium isolated from human and animal source food were studied. All the S. Typhimurium strains exhibiting multicellular behavior (100%) belonged to the ST34 type. In addition, most of the ST34-type multicellular behavior S. Typhimurium strains had a human origin (69.11%) and 98% of the ST34-type multicellular behavior strains exhibited strong biofilm formation capacity, which was much higher than that of non-multicellular behavior strains (7%, P < 0.01). Antibiotic resistance in ST34-type multicellular behavior strains was significantly higher than in strains with non-multicellular behavior for most conventional drugs (P < 0.05); notably, Polymyxin B (8%) and Imipenem (1%) resistances were also observed in the ST34-type strains. Furthermore, all the ST34-type multicellular behavior strains (100%) exhibited Multiple Drug Resistance (resistance to ≥3antibiotics), which was much higher than that of the non-multicellular behavior strains (P < 0.05). Consistent with the drug-resistant phenotype, the carrying rates of most drug-resistant genes in ST34-type multicellular behavior strains were higher than that those in non-multicellular behavior strains (P < 0.05). Therefore, this study revealed the emergence of a prevalent ST34-type multicellular behavior S. Typhimurium strains with increased biofilm formation ability and drug resistance rate, which poses a threat to public health safety, and highlights the need for comprehensive monitoring of the strains.
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Affiliation(s)
- Kaifeng Chen
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yuan Gao
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Lili Li
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Weixiao Zhang
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jiayi Li
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zhouping Zhou
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Haishan He
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zeluan Chen
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Ming Liao
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- *Correspondence: Ming Liao,
| | - Jianmin Zhang
- Center of Emerging and Zoonotic Diseases, National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Jianmin Zhang,
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Muñoz-Vargas L, Pempek JA, Proudfoot K, Eastridge ML, Rajala-Schultz PJ, Wittum T, Habing G. The Impact of Overstocking and Negative Energy Balance on Quantitative Measurement of Non-typhoidal Salmonella in Periparturient Dairy Cattle. Front Vet Sci 2022; 9:779900. [PMID: 35252416 PMCID: PMC8891502 DOI: 10.3389/fvets.2022.779900] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 01/24/2022] [Indexed: 11/14/2022] Open
Abstract
Stressful conditions in animal production facilities may exacerbate the fecal shedding and foodborne transmission of non-typhoidal Salmonella enterica subsp. enterica. Dairy cows are reservoirs of this zoonotic microorganism, and its prevalence has roughly doubled in the past decade on dairy farms in United States. Dairy cows are commonly overstocked at the feed bunk, and stressors placed on the animal prior to parturition may exacerbate Salmonella shedding. However, no studies have evaluated the impact of overstocking and metabolic stress on fecal concentrations of the pathogen. Therefore, we conducted a field trial with 120 multiparous dairy cows randomized into one of four treatment groups with different stocking densities at the feed bunk during the periparturient period as follows: US, understocked from −60 to −1 DRC; OS, overstocked from −60 to −1 DRC; USOS, understocked from −60 to −26 DRC/overstocked from −25 to −1 DRC; and OSUS, overstocked from −60 to −26 DRC/ understocked from −25 to −1 DRC. Fecal and blood samples were collected at four time points relative to calving. qPCR assays were used to quantify Salmonella invA gene and total bacterial community from fecal samples, and a subset of isolates recovered from fecal bacterial culture were characterized using pulsed field gel electrophoresis and serotyping. Serum non-esterified fatty acids (NEFA) were measured as a metabolic stress indicator using an immunoassay. Multivariable analyses were performed to test if changes in Salmonella concentrations were associated with stocking density, energy balance, or days relative to calving. From fecal isolates, three Salmonella serovars were identified, S. Cerro; Kentucky; Meleagridis. Concentrations of Salmonella increased as cows approached calving. Higher stocking densities at the feed bunk did not impact total bacterial community or NEFA; however, cows in the overstocked groups had higher Salmonella fecal concentrations. Further, cows with higher NEFA concentrations after calving had a higher likelihood of detection of Salmonella. Future farm interventions should aim to reduce environmental and metabolic stress during the periparturient period to decrease the dissemination of Salmonella to cattle, the environment, and humans.
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Affiliation(s)
- Lohendy Muñoz-Vargas
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
- *Correspondence: Lohendy Muñoz-Vargas
| | - Jessica A. Pempek
- Department of Animal Sciences, College of Food, Agricultural and Environmental Sciences, The Ohio State University, Columbus, OH, United States
| | - Kathryn Proudfoot
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Maurice L. Eastridge
- Department of Animal Sciences, College of Food, Agricultural and Environmental Sciences, The Ohio State University, Columbus, OH, United States
| | - Päivi J. Rajala-Schultz
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Thomas Wittum
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Gregory Habing
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
- Gregory Habing
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de Curraize C, Siebor E, Neuwirth C. Genomic islands related to Salmonella genomic island 1; integrative mobilisable elements in trmE mobilised in trans by A/C plasmids. Plasmid 2021; 114:102565. [PMID: 33582118 DOI: 10.1016/j.plasmid.2021.102565] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 12/01/2022]
Abstract
Salmonella genomic island 1 (SGI1), an integrative mobilisable element (IME), was first reported 20 years ago, in the multidrug resistant Salmonella Typhimurium DT104 clone. Since this first report, many variants and relatives have been found in Salmonella enterica and Proteus mirabilis. Thanks to whole genome sequencing, more and more complete sequences of SGI1-related elements (SGI1-REs) have been reported in these last few years among Gammaproteobacteria. Here, the genetic organisation and main features common to SGI1-REs are summarised to help to classify them. Their integrases belong to the tyrosine-recombinase family and target the 3'-end of the trmE gene. They share the same genetic organisation (integrase and excisionase genes, replicase module, SgaCD-like transcriptional activator genes, traN, traG, mpsB/mpsA genes) and they harbour AcaCD binding sites promoting their excision, replication and mobilisation in presence of A/C plasmid. SGI1-REs are mosaic structures suggesting that recombination events occurred between them. Most of them harbour a multiple antibiotic resistance (MAR) region and the plasticity of their MAR region show that SGI1-REs play a key role in antibiotic resistance and might help multiple antibiotic resistant bacteria to adapt to their environment. This might explain the emergence of clones with SGI1-REs.
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Affiliation(s)
- Claire de Curraize
- Bacteriology Department, University Hospital Dijon, PBHU, BP 37013, 21070 Dijon Cedex, France; UMR 6249, Chrono-Environnement, PBHU, BP 37013, 21070 Dijon Cedex, France.
| | - Eliane Siebor
- Bacteriology Department, University Hospital Dijon, PBHU, BP 37013, 21070 Dijon Cedex, France; UMR 6249, Chrono-Environnement, PBHU, BP 37013, 21070 Dijon Cedex, France.
| | - Catherine Neuwirth
- Bacteriology Department, University Hospital Dijon, PBHU, BP 37013, 21070 Dijon Cedex, France; UMR 6249, Chrono-Environnement, PBHU, BP 37013, 21070 Dijon Cedex, France.
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Mengistu G, Dejenu G, Tesema C, Arega B, Awoke T, Alemu K, Moges F. Epidemiology of streptomycin resistant Salmonella from humans and animals in Ethiopia: A systematic review and meta-analysis. PLoS One 2020; 15:e0244057. [PMID: 33332438 PMCID: PMC7746177 DOI: 10.1371/journal.pone.0244057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/02/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Streptomycin is used as an epidemiological marker in monitoring programs for antimicrobial resistance in Salmonella serovars and indicates the presence of pentaresistance. However, comprehensive data on streptomycin resistant Salmonella among human, animal, and animal products is lacking in Ethiopia. In this review, we aimed to assess heterogeneity and pooled proportion of Salmonella serovars to streptomycin resistance among human, animal and animal products in Ethiopia. METHODS We conducted a systematic review and meta-analysis of published literature from Ethiopia. We used the MEDLINE/ PubMed, Embase, Cochrane Library, and Google Scholar databases to identify genetic and phenotypic data on Salmonella isolates. To determine the heterogeneity and pooled proportion, we used metaprop commands and the random-effects model. Relative and cumulative frequencies were calculated to describe the overall preponderance of streptomycin resistance isolates after arcsine-transformed data. Metan funnel and meta-bias using a begg test were performed to check for publication bias. RESULTS Overall, we included 1475 Salmonella serovars in this meta-analysis. The pooled proportion of streptomycin resistance was 47% (95% CI: 35-60%). Sub-group analysis by target population showed that the proportion of streptomycin resistance in Salmonella serovars was 54% (95% CI: 35-73%) in animal, 44% (95% Cl: 33-59%) in humans and 39% (95% CI: 24-55%) in animals products. The streptomycin resistant Salmonella serovars were statistically increasing from 0.35(95% CI: 0.12-0.58) in 2003 to 0.77(95% CI: 0.64-0.89) in 2018. The level of multidrug-resistant (MDR) Salmonella serovars was 50.1% in the meta-analysis. CONCLUSION We found a high level of streptomycin resistance, including multidrug, Salmonella serovars among human, animals, and animal products. This resistance was significantly increasing in the last three decades (1985-2018). The resistance to streptomycin among Salmonella serovars isolated from animals was higher than humans. This mandates the continuous monitoring of streptomycin use and practicing one health approach to preventing further development of resistance in Ethiopia. REGISTRATION We conducted a systematic review and meta-analysis after registration of the protocol in PROSPERO (CRD42019135116) following the MOOSE (Meta-Analysis of Observational Studies in Epidemiology).
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Affiliation(s)
- Getachew Mengistu
- Medical Laboratory Science, College of Health Sciences, DebreMarkos University, Debre Marqos, Ethiopia
- Department of Medical Microbiology, School of Laboratory and Biomedical Science, College of Medicine and Health Science, University of Gondar, Gondar, Ethiopia
| | - Getiye Dejenu
- Department of Public Health, College of Health Sciences, DebreMarkos University, Debre Marqos, Ethiopia
| | - Cheru Tesema
- Department of Public Health, College of Health Sciences, DebreMarkos University, Debre Marqos, Ethiopia
| | - Balew Arega
- Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia
| | - Tadesse Awoke
- Department of Epidemiology and Biostatistics, Institute of Public Health, College of Medicine and Health Science, University of Gondar, Gondar, Ethiopia
| | - Kassahun Alemu
- Department of Epidemiology and Biostatistics, Institute of Public Health, College of Medicine and Health Science, University of Gondar, Gondar, Ethiopia
| | - Feleke Moges
- Department of Medical Microbiology, School of Laboratory and Biomedical Science, College of Medicine and Health Science, University of Gondar, Gondar, Ethiopia
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Roe C, Williamson CHD, Vazquez AJ, Kyger K, Valentine M, Bowers JR, Phillips PD, Harrison V, Driebe E, Engelthaler DM, Sahl JW. Bacterial Genome Wide Association Studies (bGWAS) and Transcriptomics Identifies Cryptic Antimicrobial Resistance Mechanisms in Acinetobacter baumannii. Front Public Health 2020; 8:451. [PMID: 33014966 PMCID: PMC7493718 DOI: 10.3389/fpubh.2020.00451] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/21/2020] [Indexed: 12/14/2022] Open
Abstract
Antimicrobial resistance (AMR) in the nosocomial pathogen, Acinetobacter baumannii, is becoming a serious public health threat. While some mechanisms of AMR have been reported, understanding novel mechanisms of resistance is critical for identifying emerging resistance. One of the first steps in identifying novel AMR mechanisms is performing genotype/phenotype association studies; however, performing these studies is complicated by the plastic nature of the A. baumannii pan-genome. In this study, we compared the antibiograms of 12 antimicrobials associated with multiple drug families for 84 A. baumannii isolates, many isolated in Arizona, USA. in silico screening of these genomes for known AMR mechanisms failed to identify clear correlations for most drugs. We then performed a bacterial genome wide association study (bGWAS) looking for associations between all possible 21-mers; this approach generally failed to identify mechanisms that explained the resistance phenotype. In order to decrease the genomic noise associated with population stratification, we compared four phylogenetically-related pairs of isolates with differing susceptibility profiles. RNA-Sequencing (RNA-Seq) was performed on paired isolates and differentially-expressed genes were identified. In these isolate pairs, five different potential mechanisms were identified, highlighting the difficulty of broad AMR surveillance in this species. To verify and validate differential expression, amplicon sequencing was performed. These results suggest that a diagnostic platform based on gene expression rather than genomics alone may be beneficial in certain surveillance efforts. The implementation of such advanced diagnostics coupled with increased AMR surveillance will potentially improve A. baumannii infection treatment and patient outcomes.
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Affiliation(s)
- Chandler Roe
- Northern Arizona University, Flagstaff, AZ, United States
| | | | | | - Kristen Kyger
- Northern Arizona University, Flagstaff, AZ, United States
| | - Michael Valentine
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | - Jolene R. Bowers
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | | | - Veronica Harrison
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | - Elizabeth Driebe
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | | | - Jason W. Sahl
- Northern Arizona University, Flagstaff, AZ, United States
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Dagnew B, Alemayehu H, Medhin G, Eguale T. Prevalence and antimicrobial susceptibility of Salmonella in poultry farms and in-contact humans in Adama and Modjo towns, Ethiopia. Microbiologyopen 2020; 9:e1067. [PMID: 32510864 PMCID: PMC7424249 DOI: 10.1002/mbo3.1067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/02/2020] [Accepted: 05/14/2020] [Indexed: 12/22/2022] Open
Abstract
Consumption of contaminated poultry and poultry products represents a common source of nontyphoidal Salmonella infection. Little is known on the status of Salmonella and their antimicrobial susceptibility in poultry farms in Ethiopia. This study investigated the prevalence, serotype distribution, and antimicrobial susceptibility of nontyphoidal Salmonella among poultry farms in Adama and Modjo towns. Three hundred thirty‐four cloacal swabs, 384 fecal droppings of birds, 59 feed, 59 floor swabs, and 36 stools from in‐contact humans were collected and processed for Salmonella isolation. Isolates were tested for their susceptibility to 15 antimicrobials using Kirby–Bauer disk diffusion assay. Seventeen (28.8%) of the farms and 24 (2.9%) of the samples from poultry farms and 2.8% (1/36) of stool samples of humans in‐contact with poultry were positive for Salmonella. Most of the isolates (n = 21) were recovered from fecal droppings of birds while the remaining isolates were recovered from floor swab samples (n = 2) and cloacal swab sample (n = 1). Only three Salmonella serovars: S. Haifa (n = 14, 56%), S. Anatum (n = 7; 28%), and S. Give (n = 4; 16%) were detected. Poultry farms in Adama town, large flock sized farms, and farms that used antimicrobials were significantly associated with the occurrence of Salmonella (p < .05). Twenty (80%) and 19 (76%) of Salmonella isolates were resistant to streptomycin and tetracycline, respectively. Nineteen (76%) of the isolates were resistant to two or more antimicrobials. Detection of multidrug‐resistant strains of Salmonella in poultry farms suggests the need for detailed epidemiological and molecular studies to establish sources of acquisition of resistant Salmonella strains.
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Affiliation(s)
- Betelhem Dagnew
- College of Veterinary Medicine, Samara University, Samara, Ethiopia
| | - Haile Alemayehu
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Girmay Medhin
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Tadesse Eguale
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
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Eguale T, Asrat D, Alemayehu H, Nana I, Gebreyes WA, Gunn JS, Engidawork E. Phenotypic and genotypic characterization of temporally related nontyphoidal Salmonella strains isolated from humans and food animals in central Ethiopia. Zoonoses Public Health 2018; 65:766-776. [PMID: 29984468 DOI: 10.1111/zph.12490] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 05/12/2018] [Accepted: 05/27/2018] [Indexed: 11/28/2022]
Abstract
Salmonella is one of the common causes of food-borne bacterial illnesses. The primary sources of human nontyphoidal Salmonella (NTS) infection are food animals. This study characterized temporally and spatially related Salmonella isolated during April 2013 to March 2014 from faeces of diarrhoeic human patients in Addis Ababa (n = 68) and food animals (n = 84) in Addis Ababa and surrounding districts (dairy cattle, n = 30; slaughtered cattle, n = 20; poultry, n = 26; swine n = 8). Isolates were serotyped, page typed and tested for antimicrobial susceptibility using Kirby-Bauer disc diffusion method, and genotyped by pulsed-field gel electrophoresis (PFGE). The dominant Salmonella serovars isolated from food animals were S. Saintpaul (38.1%), S. Typhimurium (17.9%) and S. Kentucky (9.5%), whereas in humans, S. Typhimurium (39.7%), S. Virchow (30.9%) and S. Kottbus (10.3%) were frequently isolated. Resistance to streptomycin, sulfisoxazole, tetracycline, ampicillin and cephalothin was higher in animal isolates than human isolates, and mean number of antimicrobials to which isolates were resistant was significantly higher in isolates from cattle and poultry compared to those from humans (p < 0.05). All S. Kentucky isolated from animals and humans were multidrug resistant (MDR) with shared resistance phenotype (AmpCfCipTeSuSNa). Although this study involved small sample size and was not able to show clear epidemiological linkage among isolates from various sources, genotyping by PFGE analysis demonstrated circulation of closely related genotypes of S. Virchow, S. Typhimurium and S. Kentucky among humans and food animals. Detection of related Salmonella isolates from humans and animals, the high MDR status of isolates from animals and close proximity of farms and human residential areas in the absence of appropriate biosecurity present major public health problem. Integrated surveillance of Salmonella serovars in humans and animals and implementation of appropriate hazard analysis and pathogen control strategies along critical points of the food chain from farm to table is recommended.
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Affiliation(s)
- Tadesse Eguale
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Daniel Asrat
- Department of Microbiology, Immunology & Parasitology, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Haile Alemayehu
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ismael Nana
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio
| | - Wondwossen A Gebreyes
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio
| | - John S Gunn
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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10
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González JF, Alberts H, Lee J, Doolittle L, Gunn JS. Biofilm Formation Protects Salmonella from the Antibiotic Ciprofloxacin In Vitro and In Vivo in the Mouse Model of chronic Carriage. Sci Rep 2018; 8:222. [PMID: 29317704 PMCID: PMC5760579 DOI: 10.1038/s41598-017-18516-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/13/2017] [Indexed: 12/05/2022] Open
Abstract
Typhoid fever is caused by the human-restricted pathogen Salmonella enterica sv. Typhi. Approximately 5% of people that resolve the disease become chronic carriers, with the gallbladder as the main reservoir of the bacteria. Of these, about 90% present with gallstones, on which Salmonella form biofilms. Because S. Typhi is a human-restricted pathogen, these carriers are the main source of dissemination of the disease; unfortunately, antibiotic treatment has shown to be an ineffective therapy. This is believed to be caused by the inherent antibiotic resistance conferred by Salmonella biofilms growing on gallstones. The gallstone mouse model with S. Typhimurium has proven to be an excellent surrogate for S. Typhi chronic infection. In this study, we test the hypothesis that the biofilm state confers Salmonella with the increased resistance to antibiotics observed in cases of chronic carriage. We found that, in the biofilm state, Salmonella is significantly more resistant to ciprofloxacin, a common antibiotic used for the treatment of Salmonella, both in vitro (p < 0.001 for both S. Typhi and S. Typhimurium with respect to planktonic cells) and in vivo (p = 0.0035 with respect to control mice).
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Affiliation(s)
- Juan F González
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
| | - Halley Alberts
- School of Mathematics and Natural Sciences, University of Rio Grande, P.O. Box 500, Rio Grande, OH, USA
| | - Joel Lee
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
| | - Lauren Doolittle
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
| | - John S Gunn
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA.
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11
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Antimicrobial resistance and resistance genes in Salmonella strains isolated from broiler chickens along the slaughtering process in China. Int J Food Microbiol 2017; 259:43-51. [DOI: 10.1016/j.ijfoodmicro.2017.07.023] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 06/15/2017] [Accepted: 07/31/2017] [Indexed: 02/07/2023]
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12
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Zhang QQ, Ye KP, Juneja VK, Xu X. Response surface model for the reduction of Salmonella
biofilm on stainless steel with lactic acid, ethanol, and chlorine as controlling factors. J Food Saf 2017. [DOI: 10.1111/jfs.12332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Qiu Qin Zhang
- College of Food Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
- Jiangsu Collaborative Innovation Center of Meat Production and Processing, Nanjing Agricultural University; Nanjing 210095 China
| | - Ke Ping Ye
- College of Food Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
| | - Vijay K. Juneja
- Jiangsu Collaborative Innovation Center of Meat Production and Processing, Nanjing Agricultural University; Nanjing 210095 China
| | - Xinglian Xu
- College of Food Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
- U.S. Department of Agriculture; Eastern Regional Research Center Agricultural Research Service; 600 East Mermaid Lane Wyndmoor Pennsylvania 19038 USA
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13
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Eguale T, Birungi J, Asrat D, Njahira MN, Njuguna J, Gebreyes WA, Gunn JS, Djikeng A, Engidawork E. Genetic markers associated with resistance to beta-lactam and quinolone antimicrobials in non-typhoidal Salmonella isolates from humans and animals in central Ethiopia. Antimicrob Resist Infect Control 2017; 6:13. [PMID: 28105330 PMCID: PMC5240271 DOI: 10.1186/s13756-017-0171-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 01/05/2017] [Indexed: 11/21/2022] Open
Abstract
Background Beta-lactam and quinolone antimicrobials are commonly used for treatment of infections caused by non-typhoidal Salmonella (NTS) and other pathogens. Resistance to these classes of antimicrobials has increased significantly in the recent years. However, little is known on the genetic basis of resistance to these drugs in Salmonella isolates from Ethiopia. Methods Salmonella isolates with reduced susceptibility to beta-lactams (n = 43) were tested for genes encoding for beta-lactamase enzymes, and those resistant to quinolones (n = 29) for mutations in the quinolone resistance determining region (QRDR) as well as plasmid mediated quinolone resistance (PMQR) genes using PCR and sequencing. Results Beta-lactamase genes (bla) were detected in 34 (79.1%) of the isolates. The dominant bla gene was blaTEM, recovered from 33 (76.7%) of the isolates, majority being TEM-1 (24, 72.7%) followed by TEM-57, (10, 30.3%). The blaOXA-10 and blaCTX-M-15 were detected only in a single S. Concord human isolate. Double substitutions in gyrA (Ser83-Phe + Asp87-Gly) as well as parC (Thr57-Ser + Ser80-Ile) subunits of the quinolone resistance determining region (QRDR) were detected in all S. Kentucky isolates with high level resistance to both nalidixic acid and ciprofloxacin. Single amino acid substitutions, Ser83-Phe (n = 4) and Ser83-Tyr (n = 1) were also detected in the gyrA gene. An isolate of S. Miami susceptible to nalidixic acid but intermediately resistant to ciprofloxacin had Thr57-Ser and an additional novel mutation (Tyr83-Phe) in the parC gene. Plasmid mediated quinolone resistance (PMQR) genes investigated were not detected in any of the isolates. In some isolates with decreased susceptibility to ciprofloxacin and/or nalidixic acid, no mutations in QRDR or PMQR genes were detected. Over half of the quinolone resistant isolates in the current study 17 (58.6%) were also resistant to at least one of the beta-lactam antimicrobials. Conclusion Acquisition of blaTEM was the principal beta-lactamase resistance mechanism and mutations within QRDR of gyrA and parC were the primary mechanism for resistance to quinolones. Further study on extended spectrum beta-lactamase and quinolone resistance mechanisms in other gram negative pathogens is recommended.
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Affiliation(s)
- Tadesse Eguale
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Josephine Birungi
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P O Box 30709, Nairobi, Kenya
| | - Daniel Asrat
- Department of Microbiology, Immunology & Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Churchill Avenue, P.O. Box 9086, Addis Ababa, Ethiopia
| | - Moses N Njahira
- ICIPE-African Insect Science for Food and Health, P.O. Box 30772-00100, Nairobi, Kenya
| | - Joyce Njuguna
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P O Box 30709, Nairobi, Kenya
| | - Wondwossen A Gebreyes
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Rd., Columbus, OH 43210 USA
| | - John S Gunn
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Biomedical Research Tower, 460 West 12th, Columbus, OH 432101214 USA
| | - Appolinaire Djikeng
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P O Box 30709, Nairobi, Kenya
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Churchill Avenue, P.O. Box 1176, Addis Ababa, Ethiopia
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14
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Loss of Multicellular Behavior in Epidemic African Nontyphoidal Salmonella enterica Serovar Typhimurium ST313 Strain D23580. mBio 2016; 7:e02265. [PMID: 26933058 PMCID: PMC4810497 DOI: 10.1128/mbio.02265-15] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Nontyphoidal Salmonella enterica serovar Typhimurium is a frequent cause of bloodstream infections in children and HIV-infected adults in sub-Saharan Africa. Most isolates from African patients with bacteremia belong to a single sequence type, ST313, which is genetically distinct from gastroenteritis-associated ST19 strains, such as 14028s and SL1344. Some studies suggest that the rapid spread of ST313 across sub-Saharan Africa has been facilitated by anthroponotic (person-to-person) transmission, eliminating the need for Salmonella survival outside the host. While these studies have not ruled out zoonotic or other means of transmission, the anthroponotic hypothesis is supported by evidence of extensive genomic decay, a hallmark of host adaptation, in the sequenced ST313 strain D23580. We have identified and demonstrated 2 loss-of-function mutations in D23580, not present in the ST19 strain 14028s, that impair multicellular stress resistance associated with survival outside the host. These mutations result in inactivation of the KatE stationary-phase catalase that protects high-density bacterial communities from oxidative stress and the BcsG cellulose biosynthetic enzyme required for the RDAR (red, dry, and rough) colonial phenotype. However, we found that like 14028s, D23580 is able to elicit an acute inflammatory response and cause enteritis in mice and rhesus macaque monkeys. Collectively, these observations suggest that African S. Typhimurium ST313 strain D23580 is becoming adapted to an anthroponotic mode of transmission while retaining the ability to infect and cause enteritis in multiple host species. IMPORTANCE The last 3 decades have witnessed an epidemic of invasive nontyphoidal Salmonella infections in sub-Saharan Africa. Genomic analysis and clinical observations suggest that the Salmonella strains responsible for these infections are evolving to become more typhoid-like with regard to patterns of transmission and virulence. This study shows that a prototypical African nontyphoidal Salmonella strain has lost traits required for environmental stress resistance, consistent with an adaptation to a human-to-human mode of transmission. However, in contrast to predictions, the strain remains capable of causing acute inflammation in the mammalian intestine. This suggests that the systemic clinical presentation of invasive nontyphoidal Salmonella infections in Africa reflects the immune status of infected hosts rather than intrinsic differences in the virulence of African Salmonella strains. Our study provides important new insights into the evolution of host adaptation in bacterial pathogens.
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Eguale T, Engidawork E, Gebreyes WA, Asrat D, Alemayehu H, Medhin G, Johnson RP, Gunn JS. Fecal prevalence, serotype distribution and antimicrobial resistance of Salmonellae in dairy cattle in central Ethiopia. BMC Microbiol 2016; 16:20. [PMID: 26879347 PMCID: PMC4754838 DOI: 10.1186/s12866-016-0638-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 02/09/2016] [Indexed: 11/10/2022] Open
Abstract
Background Salmonellae are major worldwide zoonotic pathogens infecting a wide range of vertebrate species including humans. Consumption of contaminated dairy products and contact with dairy cattle represent a common source of non-typhoidal Salmonella infection in humans. Despite a large number of small-scale dairy farms in Addis Ababa and its surrounding districts, little is known about the status of Salmonella in these farms. Results Salmonella was recovered from the feces of at least one animal in 7.6 % (10/132) of the dairy farms. Out of 1203 fecal samples examined, 30 were positive for Salmonella resulting in a weighted animal level prevalence of 2.3 %. Detection of diarrhea in an animal and in a farm was significantly associated with animal level (p = 0.012) and herd level (p < 0.001) prevalence of Salmonella. Animal level prevalence of Salmonella was significantly associated with age (p = 0.023) and study location; it was highest among those under 6 months of age and in farms from Adaa district and Addis Ababa (p < 0.001). Nine different serotypes were identified using standard serological agglutination tests. The most frequently recovered serotypes were Salmonella Typhimurium (23.3 %), S. Saintpaul (20 %), S. Kentucky (16.7 %) and S. Virchow (16.7 %). All isolates were resistant or intermediately resistant to at least one of the 18 drugs tested. Twenty-six (86.7 %), 19 (63.3 %), 18 (60 %), 16 (53.3 %) of the isolates were resistant to streptomycin, nitrofurantoin, sulfisoxazole and tetracycline , respectively. Resistance to 2 drugs was detected in 27 (90 %) of the isolates. Resistance to 3 or more drugs was detected in 21 (70 %) of the isolates, while resistance to 7 or more drugs was detected in 11 (36.7 %) of the isolates. The rate of occurrence of multi-drug resistance (MDR) in Salmonella strains isolated from dairy farms in Addis Ababa was significantly higher than those isolated from farms outside of Addis Ababa (p = 0.009). MDR was more common in S. Kentucky, S. Virchow and S. Saintpaul. Conclusion Isolation of Salmonella serotypes commonly known for causing human salmonellosis that are associated with an MDR phenotype in dairy farms in close proximity with human population is a major public health concern. These findings imply the need for a strict pathogen reduction strategy.
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Affiliation(s)
- Tadesse Eguale
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Churchill Avenue, P.O. Box 1176, Addis Ababa, Ethiopia.
| | - Wondwossen A Gebreyes
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Rd., Columbus, OH, 43210, USA.
| | - Daniel Asrat
- Department of Microbiology, Immunology & Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Churchill Avenue, P.O. Box 9086, Addis Ababa, Ethiopia.
| | - Haile Alemayehu
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
| | - Girmay Medhin
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
| | - Roger P Johnson
- Laboratory for Foodborne Zoonoses, 110 Stone Road West, Guelph, ON, N1G 3W4, Canada.
| | - John S Gunn
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Biomedical Research Tower, 460 West 12th, Columbus, OH, 43210-1214, USA.
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