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

Species distribution and antimicrobial profiles of Enterococcus spp. isolates from Kenyan small and medium enterprise slaughterhouses

The present study aimed at identifying and assessing antimicrobial resistance of Enterococcus spp. isolated from small and medium enterprise slaughterhouses in Kenya. In total, 67 isolates were recovered from 48 of 195 samples examined from beef carcasses, personnel, and cutting equipment in five small and medium enterprise slaughterhouses. The isolates were identified by using matrix-assisted laser desorption-ionization time of flight mass spectrometry and screened thereafter for their resistance against 12 antibiotics by using a disk diffusion assay. The isolates ( n = 67) included Enterococcus faecalis (41.8%), Enterococcus mundtii (17.9%), Enterococcus thailandicus (13.4%), Enterococcus faecium (9.0%), Enterococcus hirae (7.5%), Enterococcus casseliflavus (6.0%), and Enterococcus devriesei (4.5%). None of the isolates were resistant to ciprofloxacin, penicillin, ampicillin, vancomycin, nitrofurantoin, teicoplanin, linezolid, and levofloxacin. Resistance to rifampin (46.3%), erythromycin (23.9%), tetracycline (20.9%), and chloramphenicol (7.5%) was distributed among six of the seven species. All E. thailandicus were resistant to rifampin, erythromycin, and tetracycline. E. faecalis was resistant to rifampin (60.7%), tetracycline (17.9%), erythromycin (14.3%), and chloramphenicol (10.7%). Resistance to two or three antibiotics was observed in 26.9% of the enterococci isolates. The isolation of enterococci that are resistant to clinically relevant antibiotics, such as erythromycin, is of a serious concern given the role enterococci play in the transfer of antibiotic resistance genes

The Analysis of Field Strains Isolated From Food, Animal and Clinical Sources Uncovers Natural Mutations in Listeria monocytogenes Nisin Resistance Genes

Nisin is a commonly used bacteriocin for controlling spoilage and pathogenic bacteria in food products. Strains possessing high natural nisin resistance that reduce or increase the potency of this bacteriocin against Listeria monocytogenes have been described. Our study sought to gather more insights into nisin resistance mechanisms in natural L. monocytogenes populations by examining a collection of 356 field strains that were isolated from different foods, food production environments, animals and human infections. A growth curve analysis-based approach was used to access nisin inhibition levels and assign the L. monocytogenes strains into three nisin response phenotypic categories; resistant (66%), intermediate (26%), and sensitive (8%). Using this categorization isolation source, serotype, genetic lineage, clonal complex (CC) and strain-dependent natural variation in nisin phenotypic resistance among L. monocytogenes field strains was revealed. Whole genome sequence analysis and comparison of high nisin resistant and sensitive strains led to the identification of new naturally occurring mutations in nisin response genes associated with increased nisin resistance and sensitivity in this bacterium. Increased nisin resistance was detected in strains harboring RsbUG77S and PBPB3V240F amino acid substitution mutations, which also showed increased detergent stress resistance as well as increased virulence in a zebra fish infection model. On the other hand, increased natural nisin sensitivity was detected among strains with mutations in sigB, vir, and dlt operons that also showed increased lysozyme sensitivity and lower virulence. Overall, our study identified naturally selected mutations involving pbpB3 (lm0441) as well as sigB, vir, and dlt operon genes that are associated with intrinsic nisin resistance in L. monocytogenes field strains recovered from various food and human associated sources. Finally, we show that combining growth parameter-based phenotypic analysis and genome sequencing is an effective approach that can be useful for the identification of novel nisin response associated genetic variants among L. monocytogenes field strains.Peer reviewe

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

The 2022 symposium on dementia and brain aging in low‐ and middle‐income countries: Highlights on research, diagnosis, care, and impact

Two of every three persons living with dementia reside in low‐ and middle‐income countries (LMICs). The projected increase in global dementia rates is expected to affect LMICs disproportionately. However, the majority of global dementia care costs occur in high‐income countries (HICs), with dementia research predominantly focusing on HICs. This imbalance necessitates LMIC‐focused research to ensure that characterization of dementia accurately reflects the involvement and specificities of diverse populations. Development of effective preventive, diagnostic, and therapeutic approaches for dementia in LMICs requires targeted, personalized, and harmonized efforts. Our article represents timely discussions at the 2022 Symposium on Dementia and Brain Aging in LMICs that identified the foremost opportunities to advance dementia research, differential diagnosis, use of neuropsychometric tools, awareness, and treatment options. We highlight key topics discussed at the meeting and provide future recommendations to foster a more equitable landscape for dementia prevention, diagnosis, care, policy, and management in LMICs. Highlights: Two‐thirds of persons with dementia live in LMICs, yet research and costs are skewed toward HICs. LMICs expect dementia prevalence to more than double, accompanied by socioeconomic disparities. The 2022 Symposium on Dementia in LMICs addressed advances in research, diagnosis, prevention, and policy. The Nairobi Declaration urges global action to enhance dementia outcomes in LMICs

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

LACTIC ACID BACTERIA ISOLATES FROM FERMENTED CAMEL MILK (SUUSAC) ARE POTENTIAL PROTECTIVE CULTURES OF RAW CAMEL MEAT

Camel meat is the mainstay for the inhabitants of arid lands due the resilience and adaptation of camel. However, the lack of sufficient information regarding microbial stability and safety hinders utilisation and market competitiveness of the meat. This study, therefore, aimed at characterising the potential of Lactic Acid Bacteria (LAB) isolates adapted to camel meat production environment as potential protective cultures against Enterobacteriaceae-the most challenging bacterial contaminant of raw meat- present on raw camel meat. Seven LAB and ten members of Enterobacteriaceae were isolated and characterised from suusac and raw camel meat, respectively. The antimicrobial activity of the LAB against the Enterobacteriaceae members was evaluated by the agar well diffusion assay. Citrobacter spp., Shigella spp. and three out of the seven E. coli isolates were inhibited, while Salmonella spp. was not inhibited by the LAB isolates. The mean diameters of the zone of inhibition ranged from 8.5 mm to 12.5 mm. There was no significant difference between the mean diameters of inhibition zone among the inhibited Enterobacteriaceae members (P>0.05). This study established that raw camel meat may harbour foodborne pathogenic Enterobacteriaceae of a serious concern. LAB from suusac, on the other hand, may repress the growth of some of them through antagonistic interactions. Therefore, LAB showed potential as protective cultures in improving safety and quality of raw camel meat