Systematic review and meta‐analysis of the impact of decontamination interventions on the prevalence and concentration of Salmonella in broiler chickens during primary processing

SummarySystematic review and meta‐analysis aggregate quantitative data from different studies into unified effect size estimates with better statistical power in risk assessment model parameterisation. This study uses systematic review and meta‐analysis to estimate Salmonella decontamination during broiler slaughter from scalding to post‐chilling, with meta‐regression applied to explore modifier variables. Data from 161 studies published between 1998 and 2022 was extracted from thirty‐five articles identified in the systematic review process with meta‐analysis and meta‐regression performed using the metafor package (version 2.0‐0) in R statistical environment (version 3.6.0). The analysis revealed carcass wash (1.31 log$_{10}$ CFU/carcass reduction in odds; P < 0.01) and chilling (121.50% reduction in relative risk; P < 0.01) had significant reduction on Salmonella concentration and prevalence, respectively. Chemical additives reduced the concentration (0.98 log$_{10}$ CFU/carcass; P < 0.01) and prevalence (64.74% relative risk; P < 0.01) but the efficacy of physical methods was not conclusive. Application of decontaminants through immersion was superior (0.90 log$_{10}$ CFU/carcass; P < 0.01) to spraying (0.72 log$_{10}$ CFU/carcass; P < 0.01). Adjusting the pH sequentially of electrolysed water, acetic acid and trisodium phosphate reduced the odds of Salmonella concentration by more than 2 log cycles and the relative risk by more than 100%. The results provide trends in the concentration and prevalence of Salmonella during the broilers slaughter process with application of decontamination interventions and provide a basis for control decision‐making and quantitative microbial risk assessment

Systematic review and meta-analysis of the impact of decontamination interventions on the prevalence and concentration of Salmonella in broiler chickens during primary processing

DATA AVAILABILITY STATEMENT: Data available in article supplementary material.SUPPORTING INFORMATION: Data S1: Supplementary data on the systematic review on decontamination interventions on the prevalence and concentration of Salmonella in broiler chickens during primary processing.Please read abstract in article.This work was partly supported by the Australia Africa University Network- Australian Awards Africa Postdoctoral fellowship and the University of Pretoria Postdoctoral Fellowship grants.https://ifst.onlinelibrary.wiley.com/journal/13652621Consumer ScienceFood ScienceSDG-02:Zero HungerSDG-03:Good heatlh and well-bein

Systematic-review and meta-analysis on effect of decontamination interventions on prevalence and concentration of Campylobacter spp. during primary processing of broiler chickens

Please read abstract in the article.Partly supported by the Australia Awards Africa Post-Doctoral Fellowship.https://www.elsevier.com/locate/fmhj2023Consumer ScienceFood Scienc

Etiology-specific incidence and mortality of diarrheal diseases in the African region : a systematic review and meta-analysis

DATA AVAILABILITY : All results and data generated is provided within the manuscript or supplementary information files.BACKGROUND : Diarrheal diseases substantially affect public health impact in low- and middle-income countries (LMIC), particularly in Africa, where previous studies have indicated a lack of comprehensive data. With a growing number of primary studies on enteric infections in Africa, this study aimed to estimate the incidence and mortality of diarrheal pathogens across all ages in Africa in the year 2020. We also explored different methodological assumptions to allow comparison with other approaches. METHODS : Through a systematic review and meta-analysis of data from African LMICs, we estimated the etiology proportions for diarrheal diseases and deaths. We combined the etiology proportions with incidence data collected from a population survey in Africa from 2020 and mortality data from the Global Health Observatory of WHO. RESULTS : We estimated 1,008 billion diarrhea cases (95% UI 447 million-1,4 billion) and 515,031 diarrhea deaths (95% UI 248,983-1,007,641) in the African region in 2020. In children under five, enteroaggregative E. coli (EAEC) (44,073 cases per 100,000 people, 95% UI 18,818 − 60,922) and G. lamblia (36,116 cases per 100,000 people, 95% UI 15,245 − 49,961) were the leading causes of illness. Enteroinvasive E. coli (EIEC) (155 deaths per 100,000 people, 95% UI 106.5-252.9) and rotavirus (61.5 deaths per 100,000 people, 95% UI 42.3-100.3) were the primary causes of deaths. For children over five and adults, Salmonella spp. caused the largest number of diarrheal cases in the population of children ≥ 5 and adults (122,090 cases per 100,000 people, 95% UI 51,833 − 168,822), while rotavirus (16.4 deaths per 100,000 people, 95% UI 4.2–36.7) and enteroaggregative E. coli (EAEC) (14.6 deaths per 100,000 people, 95% UI 3.9–32.9) causing the most deaths. Geographically, the highest incidence of diarrhea was in Eastern Africa for children under five (114,389 cases per 100,000 people, 95% UI 34,771 − 172,884) and Central Africa for children over five and adults (117,820 cases per 100,000 people, 95% UI 75,111–157,584). Diarrheal mortality was highest in Western Africa for both children below five and above (children < 5: 194.5 deaths per 100,000 people, 95% UI 120-325.4; children ≥ 5 and above: 33.5 deaths per 100,000 people, 95% UI 12.9–75.1). CONCLUSION : These findings provide new information on the incidence and mortality of sixteen pathogens and highlight the need for surveillance and control of diarrheal infectious diseases in Africa. The cause-specific estimates are crucial for prioritizing diarrheal disease prevention in the region.This study is part of the “FOCAL (Foodborne disease epidemiology, surveillance, and Control in African LMIC)” Project, a multi-partner, multi-study research grant co-funded by the Bill & Melinda Gates Foundation and the Foreign, Commonwealth & Development Office (FCDO) of the United Kingdom Government.https://bmcpublichealth.biomedcentral.comhj2024Consumer ScienceFood ScienceSDG-03:Good heatlh and well-bein

Diversity of bacillus cereus strains in extended shelf life

Characterisation of 49 Bacillus cereus strains obtained from extended shelf life (ESL) milk and filler nozzles was done using (GTG)5 rep PCR fingerprinting, determining the presence of the virulence genes cytK, nheA, cer and hblA, and discrimination of psychrotrophic and mesophilic strains with 16S rDNA. Fourteen isolates were selected for 16S partial sequencing. Fingerprinting and sequencing showed evidence of filler nozzles contaminating ESL milk despite high heterogeneity existing between the isolates. While there is high prevalence of cer, hblA and nheA; cytK was not widely distributed. There was 100% and 8% prevalence of mesophilic and psychrotrophic signatures, respectively. Despite the large diversity of the B. cereus strains in this study, there is evidence that filler nozzles and raw milk are a source of contamination of B. cereus in ESL milk

Incidence and survival of Bacillus sporothermodurans

The presence of Bacillus sporothermodurans in retail UHT milk along with milk from different points of a processing line was determined. The effect of chilling, preheating, UHT, reprocessing and H2O2 individually and in combination on the survival of B. sporothermodurans was also investigated in broth. Design/methodology/approach - Standard plate counts were conducted for all milk samples and isolates from UHT milk were characterised using PCR. BS vegetative cells and spores in broth were subjected to various stresses encountered during UHT processing of milk. Survival counts were conducted after all treatments. Findings - B. sporothermodurans was detected in retail UHT milk packs from only one processor. UHT treatment at 140 oC for 4s eliminated B. sporothermodurans in broth. The combination of chilling and UHT was more effective in eliminating sporothermodurans spores than UHT treatment alone. H2O2 was also effective in eliminating B. sporothermodurans spores after 15 min of exposure. The adopted real time (RT) PCR with SYBR Green method was effective for the confirmation of B. sporothermodurans. Originality/Value - This research is the first to be conducted with regards to the detection of B. sporothermodurans in UHT milk in South Africa and determining the effect of UHT processing stresses on their survival. These results can be used to design processing parameters so as to effectively eliminate B. sporothermodurans spores during UHT processing. This research is the first in which RT PCR with SYBR Green has been used to characterise B. sporothermodurans.http://www.emeraldinsight.com/0007-070x.ht

Bacillus and Paenibacillus species associated with extended shelf life milk during processing and storage

Characterisation of spore formers associated with extended shelf life milk was performed by analysing the bacteriological quality of milk samples collected at various processing stages and during storage. Isolates were identified with MALDI ‐TOF ‐MS . Milk had spore counts <2 log10 cfu/mL and 4 log10 cfu/mL during processing and storage, respectively. Bacillus pumilus dominated the bacterial population. Bacterial species were inoculated into sterile milk for a shelf life study, and the population change was observed over 42 days at 7 °C. Although the extended shelf life milk process was effective in reducing bacterial counts and species diversity, the presence of Bacillus cereus shows a potential safety problem in extended shelf life milk

A High Resolution DNA Melting Curve Analysis for the Rapid and Efficient Molecular Diagnostics of Extended Spectrum β-Lactamase Determinants from Foodborne Escherichia coli

The accurate identification of Extended-Spectrum β-Lactamase (ESBL) genes in Gram-negative bacteria is necessary for surveillance and epidemiological studies of transmission through foods. We report a novel rapid, cheap, and accurate closed tube molecular diagnostic tool based on two multiplex HRM protocols for analysis of the predominant ESBL families encountered in foods. The first multiplex PCR assay targeted blaCTX-M including phylogenetic groups 1 (CTX-M-1-15, including CTX-M-1, CTX-M-3 and CTX-M-15), 2 (CTX-M-2), and 9 (CTX-M-9-14, including CTX-M-9 and CTX-M-14). The second assay involved blaTEM /bla CTX-M /blaSHV, including TEM variants (TEM-1 and TEM-2), SHV-1-56 (SHV-1, SHV-2 and SHV-56), and CTX-M-8-41 (CTX-M-8, CTX-M-25, CTX-M-26 and CTX-M-39 to CTX-M-41). The individual melting curves were differentiated by a temperature shift according to the type of ESBL gene. The specificity and sensitivity of the first assay were 100% and 98%, respectively. For the second assay, the specificity and sensitivity were 87% and 89%, respectively. The detection of ESBL variants or mutations in existing genes was also demonstrated by the subtyping of a variant of the CTXM-1-15. The HRM is a potential tool for the rapid detection of present β-lactamase genes and their characterization in a highly sensitive, closed-tube, inexpensive method that is applicable in high throughput studies.The National Research Foundation Free-standing Postdoctoral Fellowshiphttp://www.mdpi.com/journal/microorganismsam2020Consumer ScienceFood Scienc