Genomic Evaluation of Multidrug-Resistant Extended-Spectrum β-Lactamase (ESBL)-Producing from Irrigation Water and Fresh Produce in South Africa: A Cross-Sectional Analysis.

, both commensal and pathogenic, can colonize plants and persist in various environments. It indicates fecal contamination in water and food and serves as a marker of antimicrobial resistance. In this context, 61 extended-spectrum β-lactamase (ESBL)-producing from irrigation water and fresh produce from previous studies were characterized using whole genome sequencing (Illumina MiSeq).

Microbiological quality of irrigation water on highly diverse fresh produce smallholder farms: elucidating environmental routes of contamination.

Aim: To evaluate the microbiological safety, potential multidrug-resistant bacterial presence and genetic relatedness (DNA fingerprints) of Escherichia coli isolated from the water-soil-plant nexus on highly diverse fresh produce smallholder farms.

Methods And Results: Irrigation water (n = 44), soil (n = 85), and fresh produce (n = 95) samples from six smallholder farms with different production systems were analysed for hygiene indicator bacterial counts and the presence of shigatoxigenic E. coli and Salmonella spp.

Serotype Distribution, Antimicrobial Resistance, Virulence Genes, and Genetic Diversity of Salmonella spp. Isolated from small-scale Leafy Green Vegetable Supply Chains in South Africa.

Salmonella have been implicated in foodborne disease outbreaks globally and is a pressing concern in the South African small-scale sector due to inadequate hygiene standards and limited regulatory oversight, leading to a higher risk of foodborne diseases. By investigating irrigation water and leafy green vegetables produced by small-scale growers and sold through unregulated supply chains, this study was able to determine the presence, serotype distribution, virulence gene profiles, antibiotic resistance, and genetic diversity of Salmonella isolated from these sources. From 426 samples, 21 Salmonella-positive samples were identified, providing 53 Salmonella isolates.

Microbiological quality assessment of fresh produce: Potential health risk to children and urgent need for improved food safety in school feeding schemes.

About 388 million school-going children worldwide benefit from school feeding schemes, which make use of fresh produce to prepare meals. Fresh produce including leafy greens and other vegetables were served at 37% and 31% of school feeding programs, respectively, in Africa. This study aimed at assessing the microbiological quality of fresh produce grown onsite or supplied to South African schools that are part of the national school feeding programs that benefit over 9 million school-going children.

Spatial diarrheal disease risks and antibiogram diversity of diarrheagenic Escherichia coli in selected access points of the Buffalo River, South Africa.

Freshwater sources, often used for domestic and agricultural purposes in low- and middle-income countries are repositories of clinically significant bacterial pathogens. These pathogens are usually diversified in their antibiogram profiles posing public health threats. This study evaluated the spatial diarrhoeal disease risk and antibiogram diversity of diarrheagenic Escherichia coli (DEC) in four access points of the Buffalo River, Eastern Cape Province, South Africa using standard epidemiological, culture, and molecular methods.

Occurrence and Molecular Characterization of Multidrug-Resistant Vegetable-Borne Isolates.

Fresh vegetables play a significant role in the human diet. However, ready-to-eat (RTE) vegetables have been associated with increasing foodborne outbreaks including , which is a common human pathogen associated with foodborne infections resulting in listeriosis. This study aims to assess the resistance of vegetable-borne to antibiotics.

Microbiological safety of spinach throughout commercial supply chains in Gauteng Province, South Africa and characterization of isolated multidrug-resistant Escherichia coli.

Aim: To investigate the microbiological quality, potential foodborne pathogen presence, and to phenotypically (antimicrobial resistance [AMR] profiles) and genotypically (DNA fingerprints and diarrhoeagenic genes) characterize Escherichia coli isolated throughout spinach production systems from farm-to-sale.

Methods And Results: Samples (n = 288) were collected from two commercial supply chains using either river or borehole irrigation water. E.

Characterization of Multidrug-Resistant Escherichia coli Isolated from Two Commercial Lettuce and Spinach Supply Chains.

Abstract: Leafy green vegetables have increasingly been reported as a reservoir of multidrug-resistant pathogenic Enterobacteriaceae, with Shiga toxin-producing Escherichia coli frequently implicated in disease outbreaks worldwide. This study examined the presence and characteristics of antibiotic resistance, diarrheagenic virulence genes, and phylogenetic groupings of E. coli isolates (n = 51) from commercially produced lettuce and spinach from farms, through processing, and at the point of sale.

Multidrug resistant from fresh produce sold by street vendors in South African informal settlements.

The aim of this study was to assess the prevalence of commensal and pathogenic on informally sold fresh produce in South Africa, who harbour and express antimicrobial resistance genes and therefore pose indirect risks to public health. The majority (85.71%) of isolates from spinach, apples, carrots, cabbage and tomatoes, were multidrug resistant (MDR).

High prevalence of multidrug resistant Escherichia coli isolated from fresh vegetables sold by selected formal and informal traders in the most densely populated Province of South Africa.

Contaminated fresh produce has increasingly been implicated in foodborne disease outbreaks. As microbiological safety surveillance in South Africa is limited, a total of 545 vegetable samples (spinach, tomato, lettuce, cucumber, and green beans) were purchased from retailers, street traders, trolley vendors and farmers' markets. Escherichia coli, coliforms and Enterobacteriaceae were enumerated and the prevalence of Escherichia coli, Salmonella spp.

Antibiogram Signatures of Some Enterobacteria Recovered from Irrigation Water and Agricultural Soil in two District Municipalities of South Africa.

This study was undertaken to evaluate the antibiogram fingerprints of some Enterobacteria recovered from irrigation water and agricultural soil in two District Municipalities of the Eastern Cape Province, South Africa using standard culture-based and molecular methods. The prevalent resistance patterns in the isolates follow the order: serovar Typhimurium [tetracycline (92.3%), ampicillin (69.

Occurrence, Phenotypic and Molecular Characterization of Extended-Spectrum- and AmpC- β-Lactamase Producing Enterobacteriaceae Isolated From Selected Commercial Spinach Supply Chains in South Africa.

The increasing occurrence of multidrug-resistant (MDR) extended-spectrum β-lactamase- (ESBL) and/or AmpC β-lactamase-producing Enterobacteriaceae in health care systems, the environment and fresh produce is a serious concern globally. Production practices, processing and subsequent consumption of contaminated raw fruit and vegetables represent a possible human transmission route. The purpose of this study was to determine the presence of ESBL/AmpC-producing Enterobacteriaceae in complete spinach supply chains and to characterize the isolated strains phenotypically (antimicrobial resistance profiles) and genotypically (ESBL/AmpC genetic determinants, detection of class 1, 2, and 3 integrons).

Occurrence, Identification, and Antimicrobial Resistance Profiles of Extended-Spectrum and AmpC β-Lactamase-Producing from Fresh Vegetables Retailed in Gauteng Province, South Africa.

Extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase-producing are no longer restricted to the health care system, but represent increased risks related to environmental integrity and food safety. Fresh produce has been increasingly reported to constitute a reservoir of multidrug-resistant (MDR) potential human pathogenic . This study aimed to detect, identify, and characterize the antimicrobial resistance of ESBL/AmpC-producing isolates from fresh vegetables at point of sale.

Viable bacterial population and persistence of foodborne pathogens on the pear carpoplane.

Background: Knowledge on the culturable bacteria and foodborne pathogen presence on pears is important for understanding the impact of postharvest practices on food safety assurance. Pear fruit bacteria were investigated from the point of harvest, following chlorine drenching and after controlled atmosphere (CA) storage to assess the impact on natural bacterial populations and potential foodborne pathogens.

Results: Salmonella spp.

Microbiological Food Safety Status of Commercially Produced Tomatoes from Production to Marketing.

Tomatoes have been implicated in various microbial disease outbreaks and are considered a potential vehicle for foodborne pathogens. Traceback studies mostly implicate contamination during production and/or processing. The microbiological quality of commercially produced tomatoes was thus investigated from the farm to market, focusing on the impact of contaminated irrigation and washing water, facility sanitation, and personal hygiene.

Determining the potential link between irrigation water quality and the microbiological quality of onions by phenotypic and genotypic characterization of Escherichia coli isolates.

The potential transfer of human pathogenic bacteria present in irrigation water onto fresh produce was investigated, because surface water sources used for irrigation purposes in South Africa have increasingly been reported to be contaminated with enteric bacterial pathogens. A microbiological analysis was performed of a selected river in Limpopo Province, South Africa, that is often contaminated with raw sewage from municipal sewage works and overhead irrigated onions produced on a commercial farm. Counts of Escherichia coli, coliforms, aerobic bacteria, fungi, and yeasts and the prevalence of E.

Internalisation potential of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium and Staphylococcus aureus in lettuce seedlings and mature plants.

The internalisation potential of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhimurium in lettuce was evaluated using seedlings grown in vermiculite in seedling trays as well as hydroponically grown lettuce. Sterile distilled water was spiked with one of the four human pathogenic bacteria (10(5) CFU/mL) and used to irrigate the plants.

Characterization of a novel thermostable esterase from Thermus scotoductus SA-01: evidence of a new family of lipolytic esterases.

An esterase, designated EstTs1, was identified and characterized from a genomic library of Thermus scotoductus SA-01 (ATCC 700910). The library was screened in Escherichia coli for lipolytic activity on tributyrin agar plates. A 1.

Impact of inactivated extracellular proteases on the modified flagellin type III secretion pathway of Bacillus halodurans.

The flagellin type III secretion pathway of Bacillus halodurans BhFC01 (Deltahag) was modified by the inactivation of fliD. An in-frame flagellin gene fusion polypeptide construct was expressed, and the heterologous peptides were secreted as flagellin fusion monomers. The stability of the secreted monomers was significantly enhanced through gene-targeted inactivation of extracellular proteases.

Evaluation of the Staphylococcus aureus class C nonspecific acid phosphatase (SapS) as a reporter for gene expression and protein secretion in gram-negative and gram-positive bacteria.

A phosphatase secreted by Staphylococcus aureus strain 154 has previously been characterized and classified as a new member of the bacterial class C family of nonspecific acid phosphatases. As the acid phosphatase activity can be easily detected with a cost-effective plate screen assay, quantitatively measured by a simple enzyme assay, and detected by zymography, its potential use as a reporter system was investigated. The S.

Characterization of a phosphatase secreted by Staphylococcus aureus strain 154, a new member of the bacterial class C family of nonspecific acid phosphatases.

An acid phosphatase, designated SapS, hydrolyzing p-nitrophenyl phosphate (pNPP), was identified and characterized from the culture supernatant of a Staphylococcus aureus strain isolated from vegetables. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the protein indicated an estimated molecular mass of 30 kDa. The enzyme displayed optimum activity at 40 degrees C and pH 5.