scholarly journals Detection and Molecular Identification of Salmonella Virulence Genes in Livestock Production Systems in South Africa

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 124 ◽  
Author(s):  
Mthembu ◽  
Zishiri ◽  
Zowalaty

Livestock are an important source of protein and food for humans, however opportunistic pathogens such as Salmonella spp. turn livestock into vehicles of foodborne diseases. This study investigated the prevalence of virulence genes in Salmonella spp. isolated from livestock production systems in two provinces of South Africa. During the period from May to August, 2018, a total of 361 faecal (189), oral (100), environmental (soil (36) and water (27)) and feed (9) samples were randomly collected from different animals (cattle, sheep, goats, pigs, ducks and chickens) that were housed in small-scale livestock production systems from Eastern Cape and KwaZulu-Natal Provinces in South Africa. Salmonella spp. were isolated and identified using microbiological and DNA molecular methods. Salmonella spp. were present in 29.0% of the samples of which 30.2% belonged to the Salmonella enterica species as confirmed by the positive amplification of the species specific iroB gene. Virulence genes that were screened from livestock-associated Salmonella were invA, iroB, spiC, pipD and int1. Statistically significant associations (p < 0.05) were established between the virulence genes, sampling location, animal host as well as the season when samples were collected. Furthermore, statistically significant (p < 0.05) positive correlations were observed between most of the virulence genes investigated. This is one of the recent studies to detect and investigate livestock-associated Salmonella spp. in South Africa. This study highlights the importance of continuous monitoring and surveillance for pathogenic salmonellae. It also demonstrated the detection and prevalence of virulent Salmonella spp. harbored by livestock in South Africa. This study demonstrated the potential risks of pathogenic Salmonella enterica to cause foodborne diseases and zoonotic infections from farm-to-fork continuum using the global one-health approach.

2021 ◽  
Vol 9 (5) ◽  
pp. 952
Author(s):  
Nure Alam Siddiky ◽  
Md Samun Sarker ◽  
Md. Shahidur Rahman Khan ◽  
Ruhena Begum ◽  
Md. Ehsanul Kabir ◽  
...  

Virulent and multi drug resistant (MDR) Salmonellaenterica is a foremost cause of foodborne diseases and had serious public health concern globally. The present study was undertaken to identify the pathogenicity and antimicrobial resistance (AMR) profiles of Salmonellaenterica serovars recovered from chicken at wet markets in Dhaka, Bangladesh. A total of 870 cecal contents of broiler, sonali, and native chickens were collected from 29 wet markets. The overall prevalence of S. Typhimurium, S. Enteritidis, and untyped Salmonella spp., were found to be 3.67%, 0.57%, and 1.95% respectively. All isolates were screened by polymerase chain reaction (PCR) for eight virulence genes, namely invA, agfA, IpfA, hilA, sivH, sefA, sopE, and spvC. S. Enteritidis isolates carried all virulence genes whilst S. Typhimurium isolates carried six virulence genes except sefA and spvC. A diverse phenotypic and genotypic AMR pattern was found. Harmonic descending trends of resistance patterns were observed among the broiler, sonali, and native chickens. Interestingly, virulent and MDR Salmonella enterica serovars were found in native chicken, although antimicrobials were not used in their production cycle. The research findings anticipate that virulent and MDR Salmonella enterica are roaming in the wet markets which can easily anchor to the vendor, consumers, and in the food chain.


2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Stalis Norma Ethica ◽  
Hayatun Fuad ◽  
Nur Hidayah ◽  
Sri Sinto Dewi ◽  
Aditya Rahman Ernanto ◽  
...  

Detection of Salmonella bacteria based on their virulence genes is among essential steps in the eradication of clinical infection by bacteria. In this study, two pair of primers, PhoPF-PhoPR: 5’- CCGCGCAGGAAAAACTCAAA-3’ and 5’-ATCTGTTCCAGCATCACCGG -3’ as well as PhoQF-PhoQR: 5’-AGAGATGATGCGCGTACTGG-3’ and 5’- CAGACGCCCCATGAGAACAT-3’, had been successfully designed using Primer3Plus to detect the presence of phoP and phoQ genes in Salmonella spp. Using genomic DNA of 44 genomic data of Salmonella spp. as templates, PhoPF-PhoPR could produce 520-bp amplicon, while PhoQF-PhoQR could result in 598-bp amplicon. Results of in silico PCR showed that both pairs of primers PhoPF-PhoPR and PhoQF-PhoQR could detect only Salmonella enterica species, and no Salmonella bongori species could be detected based on phoP and phoQ sequences. Both pairs of PhoPF-PhoPR and PhoQF-PhoQR primers were also able to detect the virulence genes in most of the studied subspecies of Salmonella enterica available in silico database unless Arizona subspecies. As conclusion, based on this in silico study, phoP and phoQ genes appeared to be biomarkers for Salmonella enterica species. Both pairs of primers designed in this study has potential to be used as detection tool to differentiate species Salmonella enterica from Salmonella bongori, and also to distinguish S.enterica subsp. enterica from subsp. Arizonae.Keywords: Gene detection, bacterial virulence, phoP, phoQ, Salmonella spp.


2016 ◽  
Vol 79 (11) ◽  
pp. 1846-1853 ◽  
Author(s):  
MOSIMANEGAPE JONGMAN ◽  
LISE KORSTEN

ABSTRACT Foodborne disease outbreaks linked to contaminated irrigation water and fresh produce are a public health concern. The presence of Escherichia coli isolates from irrigation water and leafy green vegetables in different food production systems (large commercial farms, small-scale farms, and homestead gardens) was investigated. The prevalence of antibiotic resistance and virulence in these isolates was further assessed, and links between water source and irrigated crops were identified using antimicrobial and genotypic analyses. Presumptive E. coli isolates were identified by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy, and identities were confirmed by PCR using the uidA gene. Antimicrobial susceptibility was evaluated with the Kirby Bauer disk diffusion test; the presence of virulence genes was determined with enterobacterial repetitive intergenic consensus PCR assays. Of the 130 E. coli isolates from water (n =60) and leafy green vegetables (n =70), 19 (14.6%) were resistant to one antibiotic (tetracycline) and 92 (70.7%) were resistant to various antibiotics (including ampicillin, cefoxitin, and nalidixic acid). All E. coli isolates were susceptible to ceftriaxone and gentamicin. The virulence gene stx2 was detected in E. coli isolates from irrigation water (8 [13.3%] of 60 isolates) and cabbages (3 [7.5%] of 40), but the virulence genes eae and stx1 were not detected in any tested isolates from irrigation water and fresh produce samples. The prevalence of multidrug-resistant E. coli was lower in isolates from GLOBALG.A.P.-certified farms than in isolates from noncertified commercial and small-scale farms and homestead gardens. A link between the E. coli isolates from irrigation water sources and leafy green vegetables was established with phenotypic (antimicrobial) and genotypic (DNA fingerprinting) analyses. However, a link between virulence genes and the prevalence of antimicrobial resistance could not be established.


2008 ◽  
Vol 48 (7) ◽  
pp. 825 ◽  
Author(s):  
A. Stroebel ◽  
F. J. C. Swanepoel ◽  
N. D. Nthakheni ◽  
A. E. Nesamvuni ◽  
G. Taylor

A survey of livestock production systems was conducted in the Vhembe District, located between 22°85′ latitude and 30°71′ longitude in the Limpopo Province of South Africa. The objective of the study was to investigate the benefits obtained from, and key functions of, cattle production, as well as related breeding objectives in smallholder livestock production in the Limpopo Province of South Africa. Data were collected by means of a general survey questionnaire and a participatory rural appraisal (PRA) exercise. The results indicate that almost 60% of farmers own < 10 cattle. Female animals constituted the largest component of the herd (55.02%). Although the bull : cow ratio was extremely high (1 : 3.7), the calving rate was low at 35.60%, with an extremely high herd mortality of 15.70% and a low off-take of 8.70%. In a pairwise ranking, the benefits obtained from cattle by smallholder livestock farmers are as follows: selling and meat consumption (4), wealth, status and savings (3), socio-cultural activities (2) and draught power (1). The ‘cattle complex’, where cattle are kept for prestige and status, is still appropriate, but cattle also make significant contributions in respect to selling and meat consumption, and arable inputs such as draft and fertiliser. It is concluded that benefits obtained from cattle form the basis of decision-making by smallholder cattle owners with respect to livestock production.


Author(s):  
Tsepo A. Ramatla ◽  
Nthabiseng Mphuthi ◽  
Taole Ramaili ◽  
Moeti O. Taioe ◽  
Oriel M.M. Thekisoe ◽  
...  

Land ◽  
2013 ◽  
Vol 2 (4) ◽  
pp. 726-755 ◽  
Author(s):  
Ngufor Atanga ◽  
Anna Treydte ◽  
Regina Birner

2004 ◽  
Vol 26 ◽  
pp. 33-42 ◽  
Author(s):  
PK Thornton ◽  
RH Fawcett ◽  
KA Galvin ◽  
RB Boone ◽  
JW Hudson ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Michel Mainack Dione ◽  
Winfred Christine Amia ◽  
Francis Ejobi ◽  
Emily Awuor Ouma ◽  
Barbara Wieland

This study assessed the veterinary drug supply chain in Uganda, the constraints faced by the actors, and how the challenges influence the use of antimicrobial (AMs) by livestock farmers. We carried out stakeholder consultation workshops, key informant interviews and a knowledge, practices, and awareness survey with actors of the veterinary drug supply chain. We also profiled drugs stored in 23 urban and peri-urban drug shops in Lira and Mukono districts to record the commonly sold drugs. The veterinary drug supply chain is made of several actors including wholesalers, retailers, Animal Health Service Providers (AHSP) and farmers. Nearly ninety per cent of drug retailers and veterinary practitioners did not receive specialized training in veterinary medicine, and most of veterinary practitioners have been in the drug business market for more than 10 years. Antibiotics and anti-helminthics were the most stocked drugs by retailers, with antibiotics ranking highest in terms of contribution to annual financial profits, accounting for 33%. The choice of a drug by veterinary practitioners was mainly informed by past success with efficacy of the drug, and financial capacity of the client (the farmer) to meet the treatment cost. Many veterinary practitioners were not conversant with veterinary drug policies of the country, with Mukono having a higher number (72%) compared to Lira (37%). Veterinary practitioners from Lira district compared to Mukono and those mainly serving small scale farmers relative to large scale smallholders were more knowledgeable about antibiotics and AMR. Several supply chain constraints were identified as potential drivers of misuse of antibiotics that could contribute to AMR. These included low level of education of supply chain actors, particularly drug retailers, poor handling of drugs at purchase and administration practices, low enforcement of policies and regulations, and lack of awareness of stakeholders about policies that regulate drug use. Thus, future interventions to reduce misuse of AM drugs in livestock production systems in Uganda such as capacity building, should also target veterinary input suppliers, and deliberately involve a strong policy advocacy component.


2021 ◽  
Vol 13 (17) ◽  
pp. 9863
Author(s):  
Hemant G. Tripathi ◽  
Harriet E. Smith ◽  
Steven M. Sait ◽  
Susannah M. Sallu ◽  
Stephen Whitfield ◽  
...  

Emerging information on the interactions between the COVID-19 pandemic and global food systems have highlighted how the pandemic is accentuating food crises across Africa. Less clear, however, are how the impacts differ between farming systems. Drawing on 50 key informant interviews with farmers, village leaders and extension officers in South Africa and Tanzania, we identify the effects of COVID-19 and associated measures to curb the spread of the disease on farming production systems, the coping mechanisms adopted by farmers, and explore their longer-term plans for adaptation. We focus on a diverse range of production systems, from small-scale mixed farming systems in Tanzania to large-scale corporate farms in South Africa. Our findings highlight how COVID-19 restrictions have interrupted the supply chains of agricultural inputs and commodities, increasing the storage time for produce, decreasing income and purchasing power, and reducing labour availability. Farmers’ responses were heterogeneous, with highly diverse small-scale farming systems and those less engaged with international markets least affected by the associated COVID-19 measures. Large-scale farmers were most able to access capital to buffer short-term impacts, whereas smaller-scale farms shared labour, diversified to subsistence produce and sold assets. However, compounded shocks, such as recent extreme climate events, limited the available coping options, particularly for smaller-scale and emerging farmers. The study highlights the need to understand the characteristics of farm systems to better equip and support farmers, particularly in contexts of uncertainty. We propose that policy actions should focus on (i) providing temporary relief and social support and protection to financially vulnerable stakeholders, (ii) job assurance for farmworkers and engaging an alternative workforce in farming, (iii) investing in farming infrastructure, such as storage facilities, digital communication tools and extension services, and (iv) supporting diversified agroecological farming systems.


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