scholarly journals Antibiotic resistance and phylogenetic profiling of Escherichia coli from dairy farm soils; organic versus conventional systems

2021 ◽  
pp. 100088
Author(s):  
Omega Y Amoafo ◽  
Vanita Malekar ◽  
Eirian Jones ◽  
Stephen L W On
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Dairy Farm ◽  
Phylogenetic Profiling ◽  
Conventional Systems ◽  
Farm Soils

scholarly journals Antibiotic-resistant Escherichia coli and Salmonella spp. associated with dairy cattle and farm environment having public health significance

2019 ◽  
Vol 12 (7) ◽  
pp. 984-993 ◽  
Author(s):  
Md. Abdus Sobur ◽  
Abdullah Al Momen Sabuj ◽  
Ripon Sarker ◽  
A. M. M. Taufiqur Rahman ◽  
S. M. Lutful Kabir ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
One Health ◽  
Dairy Farm ◽  
Antibiotic Resistance Genes ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
E Coli

Aim: The present study was carried out to determine load of total bacteria, Escherichia coli and Salmonella spp. in dairy farm and its environmental components. In addition, the antibiogram profile of the isolated bacteria having public health impact was also determined along with identification of virulence and resistance genes by polymerase chain reaction (PCR) under a one-health approach. Materials and Methods: A total of 240 samples of six types (cow dung - 15, milk - 10, milkers' hand wash - 10, soil - 10 water - 5, and vegetables - 10) were collected from four dairy farms. For enumeration, the samples were cultured onto plate count agar, eosin methylene blue, and xylose-lysine deoxycholate agar and the isolation and identification of the E. coli and Salmonella spp. were performed based on morphology, cultural, staining, and biochemical properties followed by PCR. The pathogenic strains of E. coli stx1, stx2, and rfbO157 were also identified through PCR. The isolates were subjected to antimicrobial susceptibility test against 12 commonly used antibiotics by disk diffusion method. Detection of antibiotic resistance genes ereA, tetA, tetB, and SHV were performed by PCR. Results: The mean total bacterial count, E. coli and Salmonella spp. count in the samples ranged from 4.54±0.05 to 8.65±0.06, 3.62±0.07 to 7.04±0.48, and 2.52±0.08 to 5.87±0.05 log colony-forming unit/g or ml, respectively. Out of 240 samples, 180 (75%) isolates of E. coli and 136 (56.67%) isolates of Salmonella spp. were recovered through cultural and molecular tests. Among the 180 E. coli isolates, 47 (26.11%) were found positive for the presence of all the three virulent genes, of which stx1 was the most prevalent (13.33%). Only three isolates were identified as enterohemorrhagic E. coli. Antibiotic sensitivity test revealed that both E. coli and Salmonella spp. were found highly resistant to azithromycin, tetracycline, erythromycin, oxytetracycline, and ertapenem and susceptible to gentamycin, ciprofloxacin, and imipenem. Among the four antibiotic resistance genes, the most observable was tetA (80.51-84.74%) in E. coli and Salmonella spp. and SHV genes were the lowest one (22.06-25%). Conclusion: Dairy farm and their environmental components carry antibiotic-resistant pathogenic E. coli and Salmonella spp. that are potential threat for human health which requires a one-health approach to combat the threat.

Characterization of Escherichia coli and Salmonella from Victoria, Australia, Dairy Farm Environments

2017 ◽  
Vol 80 (12) ◽  
pp. 2078-2082 ◽  
Author(s):  
Catherine M. McAuley ◽  
Kate E. McMillan ◽  
Sean C. Moore ◽  
Narelle Fegan ◽  
Edward M. Fox
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Dairy Farm ◽  
Farm Animals ◽  
E Coli ◽  
Virulence Markers ◽  
Salmonella Serotypes ◽  
Serotype Identification ◽  
Salmonella Serotype ◽  
Genetic Profiles

ABSTRACT Safe dairy food production starts at the farm level, with the presence of pathogens on farms potentially impacting the downstream food supply. Studies often commence with looking for pathogens in fecal material of farm animals, predominantly cows; however, pathogens may arise from other on-farm sources. In Australia, few studies have looked at the broader farm environment, particularly in relation to Escherichia coli and Salmonella. The present study characterized the genetic similarity of these pathogens from bovine, ovine, and caprine dairy farm environments and related this to the stx1, stx2, eae, or ehx virulence markers in E. coli and antibiotic resistance in Salmonella. E. coli isolates with indistinguishable genetic profiles and at least one of the virulence factors were found in multiple samples on the farms, although profiles were unique to each farm. E. coli O26 with stx1 from one bovine farm had a different fingerprint type than all of the other E. coli O26 isolates, which lacked the Shiga toxin genes. They were from a separate bovine farm and were themselves closely related. No antibiotic resistance was detected among Salmonella isolates to the 17 antibiotics tested. Three Salmonella serotypes were identified: Orion, Infantis, and Zanzibar. The published PCR serotyping method used misidentified Salmonella Zanzibar as Salmonella Javiana, which was revealed after conventional antisera-based serotyping; this illustrates the need for caution when using PCR techniques for Salmonella serotype identification. Of the three serotypes, Salmonella Orion was most prevalent and was potentially resident on the farm. This article describes the previously unreported genetic diversity of potentially pathogenic E. coli and Salmonella serotypes from the farm environments of three dairy animal species in Victoria, Australia.

As Nascentes como Fonte de Abastecimento de Populações Rurais Difusas (The Springs as Supply Source of Rural Diffuse Population)

2012 ◽  
Vol 4 (5) ◽  
pp. 974
Author(s):  
Ricardo Augusto Pessôa Braga
Keyword(s):  
Escherichia Coli ◽  
Basic Needs ◽  
Supply Source ◽  
Rural Villages ◽  
Family Farmers ◽  
Farming Families ◽  
Water Springs ◽  
Conventional Systems ◽  
The City ◽  
Perennial Springs

A universalização do abastecimento de água no Brasil ainda é um desafio que se busca suplantar, sobretudo em relação ao atendimento a populações rurais difusas, onde os sistemas convencionais não respondem às demandas das famílias de agricultores dispersas. Nesse contexto, as nascentes de água podem contribuir como solução alternativa para o abastecimento doméstico, por se encontrarem próximas ao consumo e sob o controle do usuário Isto é evidenciado no estudo das nascentes situadas no Assentamento Serra Grande, no município de Vitória de Santo Antão, Zona da Mata de Pernambuco. Foram identificadas, cadastradas e selecionadas nascentes perenes, para caracterização da qualidade e vazão das águas, objetivando avaliá-las para usos múltiplos, com prioridade ao abastecimento doméstico. Evidenciou-se que a vazão, mesmo em períodos de estiagem, possui potencial de atender às necessidades básicas dos agricultores, para beber, preparo de alimentos, banho, lavagem de utensílios e roupas e descarga em sanitários. Quanto à qualidade para uso doméstico, em geral a água atende aos limites sanitários, embora em alguns casos a presença de Escherichia coli exija recuperação da nascente e cloração cuidadosa da água. Pelos resultados, a produção de água em nascentes situadas em solos e clima predominantes na Zona da Mata do Nordeste brasileiro, permite atender às necessidades básicas de abastecimento doméstico de agricultores familiares isolados ou em pequenas vilas rurais, sendo uma alternativa aos sistemas convencionais de abastecimento, já identificada pelo governo federal em seus recentes planos de abastecimento de populações rurais difusas. Palavras-chave: recursos hídricos; gestão ambiental; desenvolvimento rural  The Springs as Supply Source of Rural Diffuse Population  ABSTRACTThe universalization of the water supply in Brazil is still a challenge that it seeks to be supplant, especially in relation to the service to rural diffuse population, where conventional systems do not respond to the demands of farming families dispersed. In this context, the water springs may contribute as a workaround for domestic supply, because they are close to consumption and under user control. This is evidenced in the study of springs located at Settlement Serra Grande, located in the city of Vitória de Santo Antão, Zona da Mata de Pernambuco. It has been identified, registered and selected perennial springs, to characterize the quality and water flow, aiming to evaluate them for multiple uses with priority to domestic supply. It was evident that the flow even during drought periods, has potential to meet the basic needs of farmers, for drinking, preparing meals, baths, wash utensils and clothes and flushing toilets. As for the quality for home use, generally water meets health limits although in some cases the presence of Escherichia coli, requires careful recovery of the source and chlorination of water. According to the results, the production of water in springs located in soils and climate prevailing in Zona da Mata of Brazilian northeastern, it allows to meet basic needs for domestic supply from family farmers in small villages or isolated rural villages, being an alternative to conventional supply, already identified by the federal government in their recent plans for the supply of rural diffuse population.  Keywords: water resources; environmental management; rural development

scholarly journals Specific phenotypic, genomic, and fitness evolutionary trajectories toward streptomycin resistance induced by pesticide co-stressors in Escherichia coli

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yue Xing ◽  
Xiaoxi Kang ◽  
Siwei Zhang ◽  
Yujie Men
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Selective Pressure ◽  
Fold Increase ◽  
Streptomycin Resistance ◽  
Evolutionary Stage ◽  
Fitness Costs ◽  
Evolutionary Trajectories ◽  
K 12 ◽  
Late Stages

AbstractTo explore how co-occurring non-antibiotic environmental stressors affect evolutionary trajectories toward antibiotic resistance, we exposed susceptible Escherichia coli K-12 populations to environmentally relevant levels of pesticides and streptomycin for 500 generations. The coexposure substantially changed the phenotypic, genotypic, and fitness evolutionary trajectories, resulting in much stronger streptomycin resistance (>15-fold increase) of the populations. Antibiotic target modification mutations in rpsL and rsmG, which emerged and dominated at late stages of evolution, conferred the strong resistance even with less than 1% abundance, while the off-target mutations in nuoG, nuoL, glnE, and yaiW dominated at early stages only led to mild resistance (2.5–6-fold increase). Moreover, the strongly resistant mutants exhibited lower fitness costs even without the selective pressure and had lower minimal selection concentrations than the mildly resistant ones. Removal of the selective pressure did not reverse the strong resistance of coexposed populations at a later evolutionary stage. The findings suggest higher risks of the selection and propagation of strong antibiotic resistance in environments potentially impacted by antibiotics and pesticides.

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