Molecular characterization of antimicrobial multi-drug resistance in non-typhoidal Salmonellae from chicken and clam in Mangalore, India

Salmonella enterica has been documented as one of the leading causes of salmonellosis throughout the world and is most commonly associated with the consumption of contaminated food products. Thus, this research was aimed at studying the antimicrobial susceptibility pattern and detection of quinolone resistance in Salmonella spp isolated from food of animal origin. Thirty-six Salmonella isolates comprising 8 from poultry and 28 from seafood（clams） were identified, serotyped and characterized for their antimicrobial susceptibility against 10 different antibiotics. Plasmid DNA was isolated from all the isolates by alkaline lysis, quinolone resistant non-typhoidal S. Weltevreden were examined for mutation in the DNA gyrase coding gene. Among the 36 Salmonella isolates, 20 were S. weltevreden（8 from poultry and 12 from seafood） and 16 were S. Typhimurium（from seafood）. All the isolates showed multiple resistance to nalidixic acid, tetracycline, co-trimoxazole and nitrofurantoin, but, interestingly, the isolates were 100% susceptible to ampicillin, chloramphenicol and gentamicin. Resistant isolates from the study carried the genes responsible for resistance to respective antibiotics. The strain S130 isolated in the study showed single point mutation,Asp87Gly, at position 87 in quinolone resistance determining region. It revealed mutation in quinolone resistance determining region as a cause for quinolone resistance in non-typhoidal Salmonellae. The occurrence of genes accountable for plasmid mediated resistance to quinolones（viz., qnrA, qnrB and qnrS） in plasmid of non-typhoidal Salmonellae isolates provides evidence for plasmid mediated quinolone resistance.

Association of Phenotypic and Genotypic Fluoroquinolone Susceptibility among Non-Typhoidal Salmonella Isolates from Jeddah, KSA

Non-typhoid Salmonella (NTS) infects 250 to 3200 per 100,000 individuals from all over the world. NTS infection is relatively high in Jeddah (ranges between 44-132/100,000 population) as compared to other cities of Saudi Arabia. NTS isolates have also shown increasing resistance to conventional antibiotics. Therefore, fluoroquinolone (FQ) is considered drug of choice for the treatment of invasive NTS infections. A rapid detection of FQ resistance may greatly assist in appropriate therapy and containment of resistant NTS strains. Thus, molecular detection of mutations in FQ resistance genes (gyrA and parC) may play a promising role. Since limited data were available about FQ resistance among NTS isolates, therefore, this study primarily explored the occurrence of phenotypic and genotypic FQ resistance among NTS isolates from Jeddah, Saudi Arabia. Study also explored any correlation between phenotypic and genotypic FQ resistance. Fifty NTS isolates were collected from a public sector hospital of Jeddah from January to December, 2014. FQ susceptibility was determined for 48 NTS isolates using Kirby-bauer disk diffusion method and results were interpreted according to Clinical and Laboratory Standards Institute (CLSI) methodology. Genotypic resistance to FQ was determined by exploring mutations in gyrA and parC genes using PCR- based gene-sequencing method. Results were statistically analyzed using Social Package of Statistical Science (SPSS) version 22. Phenotypic antibiogram revealed that 38% (18/48) NTS isolates were FQ resistant, that 23% (11/48) were intermediately susceptible and that 39% (19/48) were susceptible. Genotypic resistance revealed mutations in only four codons of gyrA and parC genes among 39% (7/18) of FQ resistant isolates. 43% (3/7) of FQ resistant isolates showed mutations at two codons 83 (S83F, S83Y) and 87, (D87G, D87Y, D87W) of gyrA gene. Two resistant isolates showed triple mutations i.e. at codons 83 and 87 of gyrA and codon 80 (S80I and S80W) of parC gene, while one resistant isolate revealed mutation at codon 87 of gyrA and 57 (S57T) of parC gene. Moreover, 55% (6/11) intermediately susceptible isolates for FQ also revealed mutation at codon 83 of gyrA gene whereas;one intermediately susceptible isolate (1/6) also revealed additional mutation at codon 57 of parC gene. None of the FQ susceptible NTS isolates showed any mutations in gyrA or parC genes. Occurrence of mutations at only four codons in gyrA and parC genes among FQ resistant isolates may assist in development of rapid molecular method for FQ resistance detection. Presence of mutations among more than fifty percent of intermediately susceptible FQ isolates is alarming and may serve as a predictor for pre-resistant isolates for FQ. Moreover, absence of mutation in about sixty percent of phenotypically FQ resistant NTS isolates shows existence of an alternate resistance mechanism requiring further investigations.

Detection of Non-Typhoidal Salmonella Using a Mechanism for Controlling Hydrogen Sulfide Production

To know the relation between NaCl concentration and hydrogen sulfide (H2S) production by MY Phenomenon of Salmonella, we developed a method to control H2S production by Salmonella in this study. Desoxycholate-hydrogen sulfide-lactose (DHL) agar was used as the selective medium for Salmonella. Triple sugar iron (TSI) agar was used as the screening medium. Citric acid disks were placed on DHL agar. NaCl was added to both media. After 24 hours incubation, H2S production on DHL agar was stimulated by citric acid, whereas production was suppressed by adding NaCl. The color change in the bottom of the TSI medium was due to the low production of black FeS. The production of FeS was reduced by lower H2S production by Salmonella with an increasing concentration of NaCl from 0.5% to 3%. The inhibition of the black color meant that the color change due to glucose fermentation could be seen clearly in the bottom of the agar. The current method cannot detect glucose fermentation but the addition of more NaCl to the TSI medium allowed the visualization of glucose fermentation by Salmonella. Although H2S production of salmonella was promoted by citrate etc., being controlled by sodium chloride was proved in this study. Thus, we had developed a possibility of novel technique for the detection of Salmonella etc.

Occurrence of Typhoidal and Non-Typhoidal Salmonellae among Poultry Workers in the Southern, Nigeria

Typhoid fever and non-typhoidal salmonellosis remain endemic in most developing countries with large scale transmission through contaminated food and drinking water. Since the early 2000s, poultry has also been found to be a common food source for Salmonella enteritidis infections. A total of 500 blood, stool, cloaca swab and egg shell swab specimens were collected respectively from poultry, non-poultry workers and birds in Akwa Ibom State and screened for Salmonella species using standard cultural and serological techniques. The overall prevalence rate was 117 (23.4%). Salmonella species were distributed in all the three senatorial districts of the State, percentage distribution of Salmonella isolates was 42 (25%) for Uyo, 35 (20.8%) for Eket and 40 (23.8%) were isolated from Ikot Ekpene senatorial districts. Out of 372 human subjects screened 77 (20.7%) were positive and 38 (20.4%) were isolated from non-poultry workers while 39 (21.0%) were isolated from poultry Staff in the three senatorial districts. Out of 128 samples of poultry products analysed 40 (31.3%) were isolated. 23 (18%) were isolated from cloaca swabs while 17 (13.3%) were isolated from egg shell swabs. In this study, all the serological significant Typhoid fever cases were confirmed by blood culture. According to sero-grouping and source of sample collection 23.9% S. typhi was isolated from human followed by S. paratyphi A (20.5%) while S. enteritidis and S. gallinarum (19.7%). Among poultry products S. gallinarum, S. enteritidis, S, pullorum, S. paratyphi A, and S. typhimurium were isolated from bird Cloaca swab and Egg shell swab. Salmonella pullorum and S. typhi were not isolated from human and poultry respectively. High prevalence of Salmonella serovars such as S. gallinarium, S. typhi, S. Typhimurium and S. enteritidis with regular consumption of poultry and eggs without proper disinfection and appropriate boiling represent a serious public health risk in Akwa Ibom State. Demographic data obtained in this study showed that majority of the poultry workers across the three senatorial districts were within the ages of 21 to 30 (34%), 39% were none graduate while 30.4% were secondary school leavers. Fever was recorded as the highest clinical signs and symptoms followed by headache, abdominal cramps, diarrhoea and vomiting. Generally, all the isolates identified as Salmonella were tested for their susceptibility to antimicrobial agents. The results showed that Amoxacillin-Clavulanic acid was 100% susceptible to S. gallinarum, S. paratyphi A, 93% susceptible to S. typhi and 80% to S. typhimurium, S. enteritidis and S pullorum. Salmonella gallinarum was 100% sensitive to Ciprofloxacin and S. pullorum, whereas all isolates were 100% resistant to Oxacillin and Tylosin antibacterial agents used. The emergence of multiple drugs resistant Salmonella from human and poultry shows that the continuous use of drugs in poultry as growth promoters should be re-examined. Other factors as sources of Salmonella contamination in farms can be minimized by good hygienic practices and biosecurity measures.

Antibiotic Resistance Profile of Salmonella Strains Isolated at the National Clinical Biology and Public Health Laboratory in Bangui, Central African Republic

In Africa, each year, there are estimated to be more than 91 million cases of salmonellosis and 137,000 cases of death. The problem of antibiotic resistance in Salmonella strains is a threat to public health. The objective of this study is to evaluate the antibiotic resistance profile of Salmonella strains isolated in biological products analyzed at the National Laboratory of Clinical Biology and Public Health (NLCBPH) in Bangui. This is, therefore, a cross-sectional study with a descriptive aim, running from January to December 2022. It focused on the strains of Salmonella isolated and identified in stools, urines, and blood samples. For each strain of Salmonella isolated, an antibiogram was carried out following the recommendations of the French Society of Microbiology (CASFM, 2022). A total of 93 strains of Salmonella have been recorded. The age group 0 - 9 years was 29% and that of >50 years was 11%. The median age of patients was 30 years with a minimum of 1 and a maximum of 78 years. The female gender was more represented at 52.69% than the male gender at 47.31%, i.e. a sex ratio of 0.89 (M/F). Salmonella strains were much more isolated in stools at 62% followed by urines at 29% and blood at 6%. Salmonella arizonae strains were more represented with 52%. Salmonella strains have a resistance rate to Tetracycline of 62.37% followed by Penicillins of 50%. The rate of multi-antibiotic resistance of the Salmonella strains isolated represented 48.38%. Salmonella spp. strains were multi-resistant at 58.69% followed by Salmonella arizonae strains at 47.91%. There is a significant association between the different families of antibiotics and Salmonella strains (p < 0.05). According to the results obtained, Penicillins, Phenicoles, and Cyclins had a high rate of resistance on Salmonella strains. No strain-producing Broad Spectrum Beta-lactamase has been isolated. Salmonella strains represent a zoonotic health danger, constitute a public health problem and remain a current subject. This germ is resistant to the antibiotics used. It is, therefore, essential to emphasize monitoring the resistance of these germs in the Central African Republic (CAR) to improve the health of the population.

Low interleukin-10 level indicates a good prognosis in Salmonella enterica serovar typhimurium-induced pediatric hemophagocytic lymphohistiocytosis:A case report

BACKGROUND Secondary hemophagocytic lymphohistiocytosis(sHLH)triggered by Salmonella enterica serovar Typhimurium is rare in pediatric patients.There is no consensus on how to treat S.typhimurium-triggered sHLH.CASE SUMMARY A 9-year-old boy with intermittent fever for 3 d presented to our hospital with positive results for S.typhimurium,human rhinovirus,and Mycoplasma pneumoniae infections.At the time of admission to our institution,the patient’s T helper 1/T helper 2 cytokine levels were 326 pg/mL for interleukin 6(IL-6),9.1 pg/mL for IL-10,and 246.7 pg/mL for interferon-gamma(IFN-γ),for which the ratio of IL-10 to IFN-γwas 0.04.In this study,the patient received meropenem,linezolid,and cefoperazone/sulbactam in combination with high-dose methylprednisolone therapy(10 mg/kg/d for 3 d)and antishock supportive treatment twice.After careful evaluation,this patient did not receive HLH chemotherapy and recovered well.CONCLUSION S.Typhimurium infection-triggered sHLH patient had a ratio of IL-10 to IFN-γ≤1.33,an IL-10 concentration≤10.0 pg/mL,and/or an IFN-γconcentration≤225 pg/mL at admission.Early antimicrobial and supportive treatment was sufficient,and the HLH-94/2004 protocol was not necessary under these conditions.

Multidrug-Resistant of Escherichia coli and Salmonella spp. Strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso

Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.

Non-typhoidal salmonella:an unusual cause of spontaneous bacterial peritonitis in decompensated cirrhosis

Salmonella typhimurium, a non-typhoidal salmonella, is an unusual cause of spontaneous bacterial peritonitis (SBP). It isusually reported in asymptomatic patients with normal or high ascitic fluid protein levels with underlying immunosuppression,as high opsonic activity in the ascitic fluid of these patients protects them from the usual organisms causingspontaneous bacterial peritonitis, unless they are exposed to a particularly virulent organism like salmonella. We report acase of culture-proven non-typhoidal salmonella in a patient with decompensated cirrhosis, with low protein and withoutany underlying immunosuppression, and no other source to explain its origin.

Salmonella Berta myocarditis:Case report and systematic review of non-typhoid Salmonella myocarditis

AIM: To study trends in the epidemiology,clinical presentation,microbiology and prognosis of nontyphoid Salmonella(NTS) myocarditis.METHODS: We performed a systematic literature search for all reported NTS cases. The search yielded 838 publications. A total of 21 papers were deemed eligible. No language restrictions were enforced. Articles that were not written in English were translated. Pre-specified data such as clinical presentation,electrocardiogram(ECG) changes,transthoracic echocardiographic findings,cardiac magnetic resonance findings,microbiology cultures,Salmonella species,inflammatory markers(erythrocyte sedimentation rate and C-reactive protein),cardiac biomarkers and severity of illness were collected using data extraction sheets. Cases were classified by age into 2 groups; pediatric cases(defined as < 18 years old) and adult cases(defined ≥ 18 years old). The mean age of patients and standard deviations were calculated. The data was analyzed with IBM SPSS Statistics(Windows,Version 20.0. Armonk,NY: IBM Corp.) for demographic characteristics,presenting symptoms,microbiology,diagnostic methods,treatment modalities and outcome.RESULTS: From the selected articles,we identified a total of 24 individual cases with verifiable data. There were 20 males with a male to female ratio of 5:1. The mean age at presentation was 30.8 years(range 1 mo-67 years),16% of cases were children aged < 18 years. Most patients presented with chest pain,fever,and abdominal pain. The most common ECG finding was ST elevation. Cardiac biomarkers were elevated in around 70% of cases. Salmonella Enteritidis was the most common NTS isolated. Definitive diagnosis was established by blood and stool cultures in most of the cases. The pediatric and adults cases had similar incidence of bacteremia(40% vs 36.8%) while the pediatric group had more stool cultures positive compared to the adult group(100% vs 63.1%). Eightythree percent of patients received antibiotics and 58% were successfully treated through conservative management. The overall mortality was 24% and 42% of patients required intensive care.CONCLUSION: This systematic review of published cases shows that NTS myocarditis occurs predominantly in young adults and carries a poor prognosis.

Detection of non-typhoid Salmonella infection by citrus and citrus extracts in Lao PDR

Objective:To know the current state of non-typhoid Salmonella infection in Laos.To examine the usefulness of new screening methods for Salmonella using citrus.Methods:Non-typhoid Salmonella infection of person in Lao PDR was studied in this research(2004-2009).The site was Vientiane capital city in 2004.Research from rural villages locating suburb of Vientiane during 2005-2008 was carried out.Rural villages in Attapu province where ethnic minorities were living was searched for this study in 2009.During this research,to detect Salmonella strain, a new method using citrus and citrus extract named MY phenomenon that observing black ring (MIDO ring) on DHL agar was tried.The slice lemon and lime were used for this trial in 2004. After 2005,disk of ascorbic acid and citric acid were used for the device instead of citrus fruits itself.Results:During this research,65 of 272 human samples(23.9%) were infected with non- typhoid Salmonella.Conclusions:During this study,the method using citrus and citrus extracts was accepted for the detection of Salmonella.This study shows that with citrus and citrus extract, detection of Salmonella is possible using only DHL media.Results suggest that infectious rate of non-typhoid Salmonella was high.

Pretreatment with probiotics Enterococcus faecium NCIMB 11181 attenuated Salmonella Typhimurium-induced gut injury through modulating intestinal microbiome and immune responses with barrier function in broiler chickens

Background:Preventing Salmonella infection and colonization in young birds is key to improving poultry gut health and reducing Salmonella contamination of poultry products and decreasing salmonellosis for human consumption(poultry meat and eggs).Probiotics can improve poultry health.The present study was conducted to investigate the impact of a probiotics,Enterococcus faecium NCIMB 11181(E.faecium NCIMB 11181)on the intestinal mucosal immune responses,microbiome and barrier function in the presence or absence of Salmonella Typhimurium(S.Typh-imurium,ST)infection.Methods:Two hundred and forty 1-day-old Salmonella-free male broiler chickens(Arbor Acres AA+)were randomly allocated to four groups with 6 replicate cages of 10 birds each.The four experimental groups were follows:(1)nega-tive control(NC),(2)S.Typhimurium,challenged positive control(PC),(3)the E.faecium NCIMB 11181-treated group(EF),(4)the E.faecium NCIMB 11181-treated and S.Typhimurium-challenged group(PEF).Results:Results indicated that,although continuous feeding E.faecium NCIMB 11181 did not obviously alleviate growth depression caused by S.Typhimurium challenge(P>0.05),E.faecium NCIMB 11181 addition significantly blocked Salmonella intestinal colonization and translocation(P<0.05).Moreover,supplemental E.faecium NCIMB 11181 to the infected chickens remarkably attenuated gut morphological structure damage and intestinal cell apoptosis induced by S.Typhimurium infection,as evidenced by increasing gut villous height and reducing intes-tinal TUNEL-positive cell numbers(P<0.05).Also,E.faecium NCIMB 11181 administration notably promoting the production of anti-Salmonella antibodies in intestinal mucosa and serum of the infected birds(P<0.05).Addition-ally,16S rRNA sequencing analysis revealed that E.faecium NCIMB 11181 supplementation ameliorated S.Typhimu-rium infection-induced gut microbial dysbiosis by enriching Lachnospiracease and Alistipes levels,and suppressing Barnesiella abundance.Predicted function analysis indicated that the functional genes of cecal microbiome involved in C5-branched dibasic acid metabolism;valine,leucine and isoleucine biosynthesis;glycerolipid metabolism and lysine biosynthesis were enriched in the infected chickens given E.faecium NCIMB 11181.While alanine,asparate and glutamate metabolism;MAPK signal pathway-yeast;ubiquine and other terpenoid-quinore biosynthesis,protein processing in endoplasmic reticulum;as well as glutathione metabolism were suppressed by E.faecium NCIMB 11181 addition.Conclusion:Collectively,our data suggested that dietary E.faecium NCIBM 11181 supplementation could ameliorate S.Typhimurium infection-induced gut injury in broiler chickens.Our findings also suggest that E.faecium NCIMB 11181 may serve as an effective non-antibiotic feed additive for improving gut health and controlling Salmonella infection in broiler chickens.

Dietary supplementation of bilberry anthocyanin on growth performance,intestinal mucosal barrier and cecal microbes of chickens challenged with Salmonella Typhimurium

Background Anthocyanins(AC)showed positive effects on improving the intestinal health and alleviating intestinal pathogen infections,therefore,an experiment was conducted to explore the protective effects of supplemented AC on Salmonella-infected chickens.Methods A total of 240 hatchling chickens were randomly allocated to 4 treatments,each with 6 replicates.Birds were fed a basal diet supplemented with 0(CON,and ST),100(ACL)and 400(ACH)mg/kg of AC for d 60,and orally challenged with PBS(CON)or 10^(9) CFU/bird(ST,ACL,ACH)Salmonella Typhimurium at d 14 and 16.Results(1)Compared with birds in ST,AC supplementation increased the body weight(BW)at d 18 and the average daily gain(ADG)from d 1 to 18 of the Salmonella-infected chickens(P<0.05);(2)AC decreased the number of Salmonella cells in the liver and spleen,the contents of NO in plasma and inflammatory cytokines in ileal mucosa of Salmonella-infected chickens(P<0.05);(3)Salmonella infection decreased the ileal villi height,villi height to crypt depth(V/C),and the expression of zonulaoccludins-1(ZO-1),claudin-1,occludin,and mucin 2(MUC2)in ileal mucosa.AC supplementation relieved these adverse effects,and decreased ileal crypt depth(P<0.05);(4)In cecal microbiota of Salmonella-infected chickens,AC increased(P<0.05)the alpha-diversity(Chao1,Pd,Shannon and Sobs indexes)and the relative abundance of Firmicutes,and decreased(P<0.05)the relative abundance of Proteobacteria and Bacteroidota and the enrichment of drug antimicrobial resistance,infectious bacterial disease,and immune disease pathways.Conclusions Dietary AC protected chicken against Salmonella infection via inhibiting the Salmonella colonization in liver and spleen,suppressing secretion of inflammatory cytokines,up-regulating the expression of ileal barrier-related genes,and ameliorating the composition and function of cecal microbes.Under conditions here used,100 mg/kg bilberry anthocyanin was recommended.

Supplemental N-acyl homoserine lactonase alleviates intestinal disruption and improves gut microbiota in broilers challenged by Salmonella Typhimurium

Background Salmonella Typhimurium challenge causes a huge detriment to chicken production.N-acyl homoserine lactonase(AHLase),a quorum quenching enzyme,potentially inhibits the growth and virulence of Gram-negative bacteria.However,it is unknown whether AHLase can protect chickens against S.Typhimurium challenge.This study aimed to evaluate the effects of AHLase on growth performance and intestinal health in broilers challenged by S.Typhimurium.A total of 240 one-day-old female crossbred broilers(817C)were randomly divided into 5 groups(6 replicates/group):negative control(NC),positive control(PC),and PC group supplemented with 5,10 or 20 U/g AHLase.All birds except those in NC were challenged with S.Typhimurium from 7 to 9 days of age.All parameters related to growth and intestinal health were determined on d 10 and 14.Results The reductions(P<0.05)in body weight(BW)and average daily gain(ADG)in challenged birds were alleviated by AHLase addition especially at 10 U/g.Thus,samples from NC,PC and PC plus 10 U/g AHLase group were selected for further analysis.S.Typhimurium challenge impaired(P<0.05)intestinal morphology,elevated(P<0.05)ileal inflammatory cytokines(IL-1βand IL-8)expression,and increased(P<0.05)serum diamine oxidase(DAO)activity on d 10.However,AHLase addition normalized these changes.Gut microbiota analysis on d 10 showed that AHLase reversed the reductions(P<0.05)in several beneficial bacteria(e.g.Bacilli,Bacillales and Lactobacillales),along with increases(P<0.05)in certain harmful bacteria(e.g.Proteobacteria,Gammaproteobacteria,Enterobacteriaceae and Escherichia/Shigel a)in PC group.Furthermore,AHLase-induced increased beneficial bacteria and decreased harmful bacteria were basically negatively correlated(P<0.05)with the reductions of ileal IL-1βand IL-8 expression and serum DAO activity,but positively correlated(P<0.05)with the increased BW and ADG.Functional prediction revealed that AHLase abolished S.Typhimurium-induced upregulations(P<0.05)of certain pathogenicity-related pathways such as lipopolysaccharide biosynthesis,shigellosis,bacterial invasion of epithelial cells and pathogenic Escherichia coli infection of gut microbiota.Conclusions Supplemental AHLase attenuated S.Typhimurium-induced growth retardation and intestinal disruption in broilers,which could be associated with the observed recovery of gut microbiota dysbiosis.

Different Species of Salmonella spp and Shigella spp and Their Risk of Infection in N’Djamena Chad

Introduction: Salmonella and Shigella are gram-negative bacilli that are resistant to most antibiotics and play an important role in an etiology of diarrhea disease. The aim of the study was to determine the prevalence of Salmonella spp and Shigella spp isolated from stool and blood samples in the city of N’Djamena. Materials and Method: This was a prospective study conducted in the four district hospitals of N’Djamena from 14 July 2022 to 31 December 2022. A questionnaire form was drawn up to collect the information sent to the study patients. The samples were analyzed at the CHU de la Mère et de l’Enfant, Labo-Redes laboratory according to their protocols and the standard of the antibiogram committee of the French microbiology society. Results: Of the 803 biological samples analyzed, 39 were positive for Salmonella spp and Shigella spp, including 15 for Salmonella and 24 for Shigella, giving an overall prevalence rate of 4.85%. Borehole water, uncooked food and lack of access to a latrine constitute a risk of being infected by Salmonella spp and Shigella spp species. Of the 8 antibiotics tested, Salmonella spp and Shigella spp strains showed good sensitivity to nalidixic acid (100% for Salmonella and 90 for Shigella) and to ciprofloxacin (90.9% for Salmonella and 75% for Shigella). Resistance to ampicillin was found in 81.81% of Salmonella species and 78.57% of Shigella species, as was resistance to chloramphenicol (81.81% of Salmonella species and 67.85% of Shigella species). Similarly, cleanliness of the service and equipment is an essential factor in preventing Salmonella and Shigella infections.

Prevalence of Salmonella in Fresh Produce Tomatoes Sold in Open Market in Ouagadougou, Burkina Faso

Tomato is a widely consumed vegetable in Burkina Faso and throughout the world. However, when handled improperly, it can serve as a vector of pathogen transmission to human if ingested raw or through cross-contamination with cooked food. This study aimed to determine the prevalence of Salmonella spp from tomatoes sold in the markets of Ouagadougou, Burkina Faso and characteristics of vending conditions. One hundred and ninety-eight (198) different tomato samples were randomly purchased from one hundred and thirteen (113) different vendors in the markets of Ouagadougou. The samples were examined and classified into three categories according to their texture and the level of deterioration. The prevalence of Salmonella spp identification was determined using standard microbiological methods. A survey was conducted using a questionnaire on transport and vending conditions for tomatoes. In total, Salmonella prevalence was 19.19% in all tomato’s samples analyzed and was 18.18% for intact category, 22.73% in D2 category and 16.67% in category D4. The survey revealed poor transport and sales conditions for the majority of tomato sellers. The present study revealed the presence of Salmonella in tomatoes samples. These results highlight the risk associated with the consumption of tomatoes if hygienic practices are not respected during tomatoes handling and preparation. The results of the study also show the need to wash tomatoes systematically after purchase with a disinfectant, especially tomatoes sold in open markets in developing countries.

Biofilm removal mediated by Salmonella phages from chicken-related source

Salmonella and their biofilm formation are the primary bacterial causes of foodborne outbreaks and crosscontamination. The objective of the study was to investigate the potential of Salmonella phages as an alternative technology for biofilm removal. In this work, 21 Salmonella phages were isolated from a chicken farm and slaughter plant and the phage(CW1)with the broadest spectrum was characterized. Complete genome sequence analysis revealed that the genomes of phage CW1 is composed of 41 763 bp with 58 open reading frames(ORFs)and a holin-endolysin system and it does not encode any virulence or lysogeny. A phage cocktail consisted of CW1(with the broadest spectrum of 70.49%)and CW11, M4 and M10(with a high lytic activity of more than 67.11%)was established. Treatment with the cocktail reduced the cells in the developing biofilm and mature biofilm by 0.79 lg(CFU/cm~2)and 0.4 lg(CFU/cm~2), respectively. More dead cells and scattered extracellular polymeric substances(EPS)were observed by confocal laser scanning microscopy and scanning electron microscopy. Raman analysis found that carbohydrates and proteins were the identification receptors for scattered EPS. This finding suggests that this phage cockta il has potential applications for the sterilization of Salmonella biofilm during meat processing.

Dietary supplemental coated essential oils and organic acids mixture improves growth performance and gut health along with reduces Salmonella load of broiler chickens infected with Salmonella Enteritidis

Background Reducing Salmonella infection in broiler chickens by using effective and safe alternatives to antibiotics is vital to provide safer poultry meat and minimize the emergence of drug-resistant Salmonella and the spread of salmonellosis to humans.This study was to first evaluate the protective efficacy of feeding coated essential oils and organic acids mixture(EOA)on broiler chickens infected with Salmonella Enteritidis(S.Enteritidis,SE),and then its action mechanism was further explored.Methods A total of 4801-day-old Arbor Acres male chickens were randomly assigned into five treatments with six replicates,including non-challenged control fed with basal diet(A),SE-challenged control(B),and SE-infected birds fed a basal diet with 300 mg/kg of EOA(BL),500 mg/kg of EOA(BM)and 800 mg/kg of EOA(BH),respectively.All birds on challenged groups were infected with Salmonella Enteritidis on d 13.Results Feeding EOA showed a reversed ability on negative effects caused by SE infection,as evidenced by decreasing the feed conversion rate(FCR)and the ratio of villus height to crypt depth(VH/CD)(P<0.05),obviously decreasing intestinal and internal organs Salmonella load along with increasing cecal butyric acid-producing bacteria abundance(P<0.05).Moreover,supplemental different levels of EOA notably up-regulated claudin-1(CLDN-1),occludin(OCLN),zonula occludens-1(ZO-1),mucin-2(MUC-2),fatty acid binding protein-2(FABP-2),nuclear factor kappa-light-chainenhancer of activated B cells(NF-κB),myeloid differential protein-88(MyD88)and interleukin-6(IL-6)mRNA levels in the ileum of the infected chickens after challenge,whereas down-regulated toll-like receptor-4(TLR-4)mRNA levels(P<0.05).Linear discriminant analysis combined effect size measurements analysis(LEfSe)showed that the relative abundance of g_Butyricicoccus,g_Anaerotruncus and g_unclassified_f_Bacillaceae significantly was enriched in infected birds given EOA.Also,phylogenetic investigation of communities by reconstruction of unobserved states(PICRUSt)analysis showed that alpha-linolenic acid metabolism,fatty acid metabolism and biosynthesis of unsaturated fatty acids were significantly enriched in the EOA group.Conclusion Our data suggest that the essential oils and organic acids mixture can be used as an effective strategy to ameliorate and alleviate Salmonella Enteritidis infection in broilers.

Prevalence and Antimicrobial Susceptibility Patterns of Escherichia Coli and Salmonella Typhi Isolated from Meat and Fish Samples from Selected Markets in a Metropolis and District in Ghana

Antimicrobial resistance has become a major challenge to the treatment and prevention of infections resulted in high morbidity and mortality globally. The inappropriate or abuse of antibiotics in animal farming is a key factor and thus led to the emergence of bacteria resistance and subsequent transfer of resistance genes to humans through the food chain. This study was to determine the prevalence of Salmonella typhi (S. typhi) and Escherichia coli (E. coli) isolated from various meat and fish samples and their susceptibility patterns against five commonly used antibiotics in Ghana (Ciprofloxacin 5 μg, Amoxicillin-clavulanic acid 20/10 μg, Imipenem 10 μg, Tetracycline 30 μg and Ceftazidime 30 μg). A total of 105 meat and fish samples were obtained from Tema and Prampram markets and bacteria isolation was carried out using appropriate selective microbial culture media and various biochemical methods for identification. The susceptibility patterns were determined using the Kirby-Bauer disk diffusion method and the results were interpreted using the CLSI 2020 guidelines. The results revealed a total of 56 bacterial isolates comprising 14 E. coli (25%) and 42 S. typhi (75%) isolated from the meat and fish samples. The antibiogram study showed a high resistance rate (88.64%) of S. typhi isolates to amoxicillin-clavulanic acid and tetracycline (97.73%). A moderate susceptibility of the isolates was obtained with imipenem (53.27%). All the E. coli isolates were resistant to tetracycline (100%) and demonstrated 78.57% and 50% resistance to amoxicillin-clavulanic acid and ceftazidime respectively. A total of 78.57% of the E. coli isolates and 68.18% of S. typhi isolates showed multidrug resistance. The multiple antibiotic resistance (MAR) index for all the isolates ranged from 0.2 to 1.00 with two S. typhi isolates and one E. coli isolate having a MAR index of 1.00 signifying total resistance to all the 5 antibiotics tested. In conclusion, E. coli and S. typhi isolated from the meat samples exhibited high rate of resistance against the antibiotics tested and thus possesses a major health risk due to inappropriate use of antibiotics in animal and fish farming and possible transfer of resistant strains to humans.

Cross-protective effect of acid adaptation on ethanol tolerance in Salmonella Enteritidis

Cross protection can undermine the effectiveness of control measures on foodborne pathogens,and therefore brings major implications for food safety.In this work,the capacity of Salmonella Enteritidis to mount ethanol tolerance following acid adaptation was characterized by analysis of cell viability and cell membrane property.It was observed that preadaptation to pH 4.5 significantly(P<0.05)increased the tolerance of log-phase cells to ethanol;in contrast,stationary-phase cells displayed reduced ethanol tolerance after acid adaptation.However,acid adaptation did not cause cell leakage and morphological change in both log-phase and stationary-phase S.Enteritidis.Fatty acid analysis further revealed that the amount of C_(14:0),C_(17:0 cyclo) and C_(19:0 cyclo) fatty acids was increased,while that of C_(16:1ω7c) and C_(18:1ω7c) fatty acids was decreased,respectively,in response to acid adaptation,regardless of bacterial growth phase.Notably,acid adaptation significantly(P<0.05)increased the proportion of C_(16:0) fatty acid in log-phase cells,but this effect did not occur in stationary-phase cells.Moreover,exogenous addition of C_(16:0) fatty acid to stationary-phase acid-adapted cultures was able to enhance bacterial ethanol tolerance.Taken together,C_(16:0) fatty acid is involved in the growth-phase-dependent protective effect of acid adaptation on ethanol tolerance in S.Enteritidis.

Evaluation of the Microbiological Quality of Poultry Imported into Togo and the Antibiotic Resistance of Salmonella spp. Isolated

In Togo, despite the government’s efforts, food requirements in terms of animal proteins are not covered by national production and are subject to huge imports of meat products. However, the hygienic quality of these imports is not guaranteed for the consumer. The aim of this study was to estimate the frequency of unhygienically unsatisfactory imported poultry and to determine the antibiotic resistance profile of Salmonella spp. strains. A total of 285 samples of imported poultry, including 55 chicken thighs, 10 chicken backbones, 25 chicken wings, 5 whole chickens, 30 sausages, 35 chicken forequarters, 95 chicken drumsticks and 30 guinea fowl wings, were analyzed using standard AFNOR routine methods. The following germs were tested: Total Aerobic Mesophilic Flora (TAMF), Anaerobic-Sulfite-Reducing (ASR), Escherichia coli, Staphylococcus aureus and Salmonella spp. Antibiotic susceptibility testing was carried out on Salmonella spp. strains isolated using the agar disk diffusion method (CA-SFM). Results showed 100% compliance for TAMF, coagulase-positive Staphylococci and Escherichia coli. On the other hand, 3.84% and 2.46% non-compliance were recorded for ASR and Salmonella respectively. Non-compliance with hygiene rules is generally thought to be the cause of meat contamination. Seven 7 strains of Salmonella were isolated, 5 of which were of the OMA serogroup, and the other two of the OMB and HMB groups. Antibiotic susceptibility tests revealed resistance to certain beta-lactam antibiotics and quinolones, in particular: cefalexin (28.57%), cefoxitin (14.28%), cefuroxime (28.57%), ceftazidime (28.57%), ceftriaxone (28.57%) and nalidixic acid (28.57%). This result may be explained by the uncontrolled use of B-lactam and quinolone antibiotics in poultry farming. As Salmonella spp. is a pathogenic enteric bacterium that causes food-borne illness in humans, resistance to third-generation cephalosporins remains a major public health problem.