Microbial- and Plant-Derived Bioactive Peptides and Their Applications against Foodborne Pathogens: Current Status and Future Prospects.

Bioactive peptides (BAPs) obtained from plants and microbes have been thoroughly explored and studied due to their prophylactic properties. The use of BAPs seems to be a promising substitute for several currently available antibiotics because of their antimicrobial properties against foodborne pathogens. BAPs have several other useful properties including antitumor, antihypertensive, antioxidant, antiobesity, and antidiabetic activities. Nowadays, scientists have attempted to recombinantly synthesize bioactive peptides to study their characteristics and potential uses, since BAPs are not found in large quantities in nature. Many pathogenic microorganisms including foodborne pathogens are becoming resistant to various antibiotics. To combat these pathogens, scientists are working to find novel, innovative, and safe antimicrobial agents. Plant- and microbe-based BAPs have demonstrated noteworthy antimicrobial activity against a wide range of pathogenic microorganisms, including foodborne pathogens. BAPs can kill pathogenic microorganisms by disrupting membrane integrity, inhibiting DNA and RNA synthesis, preventing protein synthesis, blocking protein activity, or interacting with certain intracellular targets. In addition, the positive effect of BAP consumption extends to gut microbiota modulation and affects the equilibrium of reactive oxygen species in the gut. This article discusses recombinant BAPs, BAPs generated from plants and microbes, and their antimicrobial applications and modes of action for controlling foodborne pathogens.

Antibody Response after Homologous and Heterologous Prime-Boost COVID-19 Vaccination in a Bangladeshi Residential University Cohort.

COVID-19 vaccination strategies, including heterologous prime-boost regimens and additional booster doses, aim to optimize immune responses. However, seroepidemiological studies on immune responses to different COVID-19 vaccine types and schedules remain limited. This study investigated antibody levels following homologous and heterologous prime-and-boost COVID-19 vaccination in Bangladesh. In a cohort of 606 participants who received first/second/booster doses of vaccines (AstraZeneca, Moderna, Pfizer-BioNTech, and Sinopharm), anti-spike IgG and anti-nucleocapsid IgG levels were measured. Antibody titer variations with respect to age, gender, intervals between doses, and prior infection status were analyzed. mRNA vaccines elicited the highest antibody levels after homologous and heterologous boosting. The AstraZeneca booster resulted in a sharp titer decline rate of ~0.04 units per day. Second or booster vaccine doses significantly increased antibody levels, especially in males (p < 0.05). Older age correlated with higher titers, likely reflecting previous infection, which was further confirmed by the elevation of anti-nucleocapsid IgG levels. About 95.5% of non-Sinopharm recipients were anti-nucleocapsid IgG positive, suggesting prior exposure exceeding self-reported infections (12.5%). mRNA and heterologous COVID-19 boosting enhances humoral immunity over homologous prime-boost vector/inactivated vaccination. However, waning immunity merits further investigation across vaccine platforms.

Gut microbiota shifts favorably with delivery of handwashing with soap and water treatment intervention in a prospective cohort (CHoBI7 trial).

BACKGROUND: Cholera can result in the expulsion of important microbiota from the gut and result in death if left untreated. The disease transmits mainly via drinking water carrying Vibrio cholerae; and household contacts (HHC) of cholera patients are at elevated risk during the first week of infection. The gut microbiota profiles of HHC-children of cholera patients at Dhaka city slums were investigated before (day 0) and after (day 8) delivery of chlorinated water as part of the major study 'CHoBI7 trial (cholera-hospital-based intervention for 7 days)'. RESULT: Results of sequencing and analysis of bacterial community DNA revealed the predominance of two bacterial phyla: Bacteroidetes and Firmicutes at day 0 with a relative abundance of 62 ± 6 (mean ± SEM%) and 32 ± 7, respectively. The pattern reversed at day 8 with a decreased relative abundance of Bacteroidetes (39 ± 12; p = 0.034) and an increased abundance of Firmicutes (49 ± 12; p = 0.057). Of 65 bacterial families confirmed at day 0, six belonging to Proteobacteria including Vibrionaceae disappeared at day 8. Interestingly, the relative abundance of four Firmicutes families-Lachnospiraceae, Bifidobacteriaceae, Clostridiaceae, and Ruminococcaceae was increased in all five study children at day 8. CONCLUSION: The observed exclusion of pathogenic Proteobacteria and enhancement of beneficial Firmicutes in the gut of children delivered with chlorinated water as part of WASH intervention reflect a great promise of the CHoBI7 program in preventing cholera and improving child health.

Vibrio cholerae O1 associated with recent endemic cholera shows temporal changes in serotype, genotype, and drug-resistance patterns in Bangladesh.

BACKGROUND: Despite the advancement in our understanding of cholera and its etiological agent, Vibrio cholerae, the prevention and treatment of the disease are often hindered due to rapid changes in drug response pattern, serotype, and the major genomic islands namely, the CTX-prophage, and related genetic characteristics. In the present study, V. cholerae (n = 172) associated with endemic cholera in Dhaka during the years 2015-2021 were analyzed for major phenotypic and genetic characteristics, including drug resistance patterns. RESULTS: Results revealed that the V. cholerae strains belonged to serogroup O1 biotype El Tor carrying El Tor -specific genes rtxC, tcpA El Tor, and hlyA El Tor, but possessed classical-biotype cholera toxin. Serotypes of V. cholerae strains differed temporally in predominance with Inaba during 2015-2017, and again in 2020-2021, while Ogawa was the predominant serotype in 2018-2019. Also, ctxB1 was predominant in V. cholerae associated with cholera during 2015-2017, while ctxB7 was predominant in 2018, and in the subsequent years, as observed until 2021. V. cholerae strains differed in their antibiotic resistance pattern with a majority (97%) being multi-drug resistant (MDR) and belonging to six sub-groups. Notably, one of these MDR strains was resistant to eleven of the eighteen antibiotics tested, with resistance to fourth-generation cephalosporin (cefepime), and aztreonam. This extreme drug resistant (XDR) strain carried resistance-related genes namely, extended-spectrum ß-lactamases (ESBL), blaOXA-1 and blaPER-3. CONCLUSION: The observed temporal switching of serotypes, as well as the ctxB genotype, and the emergence of MDR/XDR V. cholerae and their association with endemic cholera in Dhaka underscore the need for routine monitoring of the pathogen for proper patient management.

Prevalence of hepatitis B and C, and syphilis among aspirant migrant workers of Bangladesh.

Background: In Bangladesh, labour migration is a source of employment and workers' remittances are critical to poverty mitigation. The aim of this study was to assess the prevalence of hepatitis B, C, HIV, tuberculosis, syphilis, kidney and liver diseases along with presence of infections among aspirant migrant workers of Bangladesh. Method: This study was carried out from September-December 2019. We analysed data collected on screening tests of specific diseases of aspirant workers. For each test, the prevalence was computed with 95% confidence interval. Association between categorical data was determined by the Chi-square test. Results: A total of 2385 aspirants, 1988 (83.35%) males, aged between 18 and 65 years (29.76±6.578) were studied. Positive results for screening tests of HBsAg were 38 (1.6%,), anti-HCV were 2 (0.08%), TPHA were 25 (1.05%) and VDRL were 5 (0.21%) though no individual was positive for HIV and TB. Elevated level of SGOT (n=99, 4.2%), SGPT (n=322, 13.5%), RBS (n=57, 2.4%), bilirubin (n=46, 1.92%), creatinine (n=7, 0.3%) and ESR (n=19, 0.8%) were found in the workers. Conclusion: Diagnosis of diseases of workers is obligatory before going abroad to safeguard the health of the workers and residents of destination country. Consequently, it will contribute to reducing the global burden of infectious diseases.

Fecal Sampling of Soil, Food, Hand, and Surface Samples from Households in Urban Slums of Dhaka, Bangladesh: An Evidence-Based Development of Baby Water, Sanitation, and Hygiene Interventions.

The aim of this study was to identify the exposure pathways of fecal pathogens for a pediatric population living in the urban slums of Bangladesh. A total of 252 soil, food, surface, and hand rinse samples were collected from the pilot households with children less than 5 years of age. All samples were analyzed using the IDEXX Quanti-Tray System (Colilert-18) to enumerate fecal indicator bacteria Escherichia coli. Escherichia coli was detected in all soil samples collected from children play spaces (N = 46), 35% of objects and surfaces children frequently put in their mouths, and 31% of child food samples. Thirty-three percent of hand samples from the child and 46% of hand samples from the caregiver had detectable E. coli. These findings showed high fecal contamination of soil, food, and on hands and surfaces in households with young children and demonstrate the need for interventions reducing these exposure pathways for susceptible pediatric populations.

Effects of a Water, Sanitation, and Hygiene Mobile Health Program on Diarrhea and Child Growth in Bangladesh: A Cluster-randomized Controlled Trial of the Cholera Hospital-based Intervention for 7 Days (CHoBI7) Mobile Health Program.

BACKGROUND: The Cholera Hospital-Based Intervention for 7 Days (CHoBI7) mobile health (mHealth) program was a cluster-randomized controlled trial of diarrhea patient households conducted in Dhaka, Bangladesh. METHODS: Patients were block-randomized to 3 arms: standard message on oral rehydration solution use; health facility delivery of CHoBI7 plus mHealth (no home visits); and health facility delivery of CHoBI7 plus 2 home visits and mHealth. The primary outcome was reported diarrhea in the past 2 weeks collected monthly for 12 months. The secondary outcomes were stunting, underweight, and wasting at a 12-month follow-up. Analysis was intention-to-treat. RESULTS: Between 4 December 2016 and 26 April 2018, 2626 participants in 769 households were randomly allocated to 3 arms: 849 participants to the standard message arm, 886 to mHealth with no home visits arm, and 891 to the mHealth with 2 home visits. Children <5 years had significantly lower 12-month diarrhea prevalence in both the mHealth with 2 home visits arm (prevalence ratio [PR]: 0.73 [95% confidence interval {CI}, .61-.87]) and the mHealth with no home visits arm (PR: 0.82 [95% CI, .69-.97]). Children <2 years were significantly less likely to be stunted in both the mHealth with 2 home visits arm (33% vs 45%; odds ratio [OR]: 0.55 [95% CI, .31-.97]) and the mHealth with no home visits arm (32% vs 45%; OR: 0.54 [95% CI, .31-.96]) compared with children in the standard message arm. CONCLUSIONS: The CHoBI7 mHealth program lowered pediatric diarrhea and stunting among diarrhea patient households. CLINICAL TRIALS REGISTRATION: NCT04008134.

Child mouthing of soil and presence of animals in child sleeping spaces are associated with growth faltering among young children in Dhaka, Bangladesh (CHoBI7 Program).

OBJECTIVE: The objective of the study was to investigate potential risk factors for growth faltering among children under 5 years of age. METHOD: We conducted a prospective cohort study of 553 children under 5 years from diarrhoea patient households in urban Dhaka, Bangladesh. Height and weight measurements were obtained at baseline and at a 12-month follow-up. Caregivers of young children were administered a monthly questionnaire on household sociodemographic characteristics and hygiene practices. RESULTS: Children with caregiver reports of mouthing soil at the majority of household visits had a significant reduction in their height-for-age z-scores (HAZ) from baseline to the 12-month follow-up (ΔHAZ: -0.28 (95% confidence interval (CI): -0.51, -0.05)). A significant reduction in HAZ was also observed for children in households with animals in their sleeping space (ΔHAZ: -0.37 (95% CI: -0.71, -0.04)). CONCLUSION: These findings provide further evidence to support the hypothesis that child mouthing of soil and the presence of animals in the child's sleeping space are potential risk factors for growth faltering among young children. Interventions are urgently needed to provide clean play and sleeping spaces for young children to reduce exposure to faecal pathogens through child mouthing.

OBJECTIF: L'objectif de l'étude était d'examiner les facteurs de risque potentiels de retard de croissance chez les enfants de moins de 5 ans. MÉTHODE: Nous avons mené une étude de cohorte prospective sur 553 enfants de moins de 5 ans provenant de ménages avec des patients diarrhéiques dans la ville de Dhaka, au Bangladesh. Les mesures de taille et de poids ont été obtenues au départ et à 12 mois de suivi. Les personnes s'occupant de jeunes enfants (les gardiens) ont reçu un questionnaire mensuel sur les caractéristiques sociodémographiques des ménages et les pratiques d'hygiène. RÉSULTATS: Les enfants pour lesquels les gardiens ont déclaré qu'ils mâchouillaient de la terre lors de la majorité des visites à domicile présentaient une diminution du score Z de taille pour l'âge (TAZ) de manière significative de l'âge de référence au 12 mois de suivi (ΔTAZ −0,28 (intervalle de confiance (IC) à 95%: −0,51, −0,05)). Une réduction significative des TAZ a également été observée pour les enfants des ménages ayant des animaux dans leur espace de couchage (ΔTAZ −0,37 (IC95%: −0,71, −0,04)). CONCLUSION: Ces résultats apportent des données supplémentaires pour appuyer l'hypothèse selon laquelle le fait que l'enfant mâchouille de la terre et la présence d'animaux dans son espace de couchage sont des facteurs de risque potentiels de retard de croissance chez les jeunes enfants. Des interventions sont urgemment nécessaires pour fournir des espaces de jeu et de sommeil sains aux jeunes enfants afin de réduire l'exposition aux agents pathogènes fécaux par le mâchouillement des enfants.

Colistin-resistant Escherichia coli carrying mcr-1 in food, water, hand rinse, and healthy human gut in Bangladesh.

BACKGROUND: One of the most significant public health concerns in today's world is the persistent upsurge of infections caused by multidrug resistant bacteria. As a result, clinicians are being forced to intervene with either less effective backup drugs or ones with substantial side-effects. Colistin is a last resort antimicrobial agent for the treatment of infections caused by multi-drug resistant gram-negative bacteria. METHODS: Escherichia coli (n = 65) isolated from street food (n = 20), hand rinse (n = 15), surface water (n = 10), and healthy human stool (n = 20) were tested for colistin resistance gene mcr-1 and response to antimicrobial agents. Antimicrobial resistance genes and virulence genes were detected by employing polymerase chain reaction. DNA fingerprinting of the strains were determined by pulsed-field gel electrophoresis. RESULTS: Screening of E. coli allowed us to confirm colistin resistance marker gene mcr-1 in 13 strains (street food, n = 4; hand rinse, n = 2; surface water, n = 4; and stool, n = 3); and two of these E. coli strains carrying mcr-1 harbored bla TEM gene encoding extended spectrum beta lactamase. Antibiotic assay results revealed all 13 E. coli strains carrying mcr-1 to be multi-drug resistant (MDR), including to colistin. The minimum inhibitory concentration (MIC) for colistin ranged from 2 to 6 µg/ml. DNA sequencing confirmed homogeneity of the nucleotide sequence for mcr-1, but the E. coli strains were heterogenous, as confirmed by pulsed-field gel electrophoresis suggesting horizontal transmission of colistin resistance in Bangladesh. CONCLUSION: Widespread dissemination of E. coli strains carrying mcr-1 encoding resistance to colistin in the present study is alarming as this is the last resort drug for the treatment of infections caused by MDR gram-negative bacteria resistant to almost all drugs used commonly.

Bacteriological assessments of foodborne pathogens in poultry meat at different super shops in Dhaka, Bangladesh.

Poultry is now considered as a major fast-growing source of meat in the world. The consumers demand safe and hygienic products without contamination with pathogenic microorganisms when the production and consumption of poultry meat is gradually increasing. The present study was conducted to assess the bacterial contamination of dressed chicken collected from different supershops in Dhaka, Bangladesh. The chicken samples from S1, S2, M1, M2 and A supershops were analyzed to determine the enteropathogenic bacteria in poultry meat. Three genera of bacteria were isolated from all of the chicken meat samples. These enteropathogens from various organs of dressing chickens were also enumerated. The isolates were presumptively identified as E. coli, Salmonella spp., and Shigella spp. by conventional culture method. The three enteropathogens were subjected to PCR assay for their confirmation as virulent enteropathogens. Only E. coli isolates were confirmed as pathogenic E. coli (Enterotoxigenic), other isolates were not confirmed as virulent Salmonella spp., Shigella spp.. Results of this study demonstrated that more cautions are recommended for personnel hygiene in processing and handling of poultry and poultry products to prevent occurrence of enterotoxigenic E. coli in dressed poultry meat sold by the supershops in Bangladesh.