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760 result(s) for "Campylobacter - drug effects"
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Phenotypic and Genotypic Characterization of Antimicrobial Resistance in Thermophilic Campylobacter Species Isolated From Faecal Samples of Chicken and Turkey
Background Thermophilic Campylobacter species cause significant economic losses in cases of enteritis in poultry. Objective The aim of this study was to isolate and identify Campylobacter jejuni, Campylobacter coli and Campylobacter lari from chicken and turkey faeces samples using bacteriological and molecular methods. Also, to determine the antibiotic susceptibilities and antibiotic resistance genes of the isolates. Materials and Methods Within the scope of the study, 201 cloacal swab samples were collected from 132 chickens and 69 turkeys. Phenotypic and genotypic examinations were performed on the isolates obtained for resistance to various antimicrobial agents. Results Campylobacter spp. was isolated from 38.30% of the samples. PCR (polymerase chain reaction) analysis identified 63.63% of the isolates as C. jejuni and 23.37% as C. coli. The highest resistance rates of the isolates were determined against cephalothin (81.81%), nalidixic acid (72.72%) and aztreonam (61.03%). Multidrug resistance was found in 50% of Campylobacter spp. strains. The highest susceptibility in C. jejuni and C. coli strains was observed against gentamicin (95.91% and 100%). Statistical analyses demonstrated no significant differences between C. jejuni and C. coli with respect to most of the antibiotics tested (p > 0.05). However, a statistically significant difference was observed for nalidixic acid (p = 0.009). The blaOXA‐61 gene tested positive in 79.71% of the phenotypically ampicillin‐resistant isolates. The tet(O) gene was identified in 72.2% of tetracycline‐resistant isolates and the aphA‐3‐1 gene in 5.8% of aminoglycoside‐resistant isolates. The ERY2074 and ERY2075 genes were identified in 50% and 78.57% of the 28 isolates with erythromycin resistance genes, respectively. The cmeA, cmeB and cmeC genes were identified in 51.28%, 79.48% and 25.6% of the strains that developed multidrug resistance, respectively. The Thr‐86‐Ile point mutation was found in 92% of the isolates that carried the gyrA gene responsible for quinolone resistance. Conclusion The high susceptibility of the isolates to gentamicin in vitro suggests that gentamicin could be a potential agent for limiting Campylobacter colonization in poultry. High rates of multidrug resistance (MDR) and resistance genes against critical antibiotics, particularly quinolones and macrolides, were detected in poultry isolates. This finding poses a significant human health risk via the food chain and underscores the urgency of enhanced biosecurity measures.
Gut microbiome alteration in MORDOR I: a community-randomized trial of mass azithromycin distribution
The MORDOR I trial 1 , conducted in Niger, Malawi and Tanzania, demonstrated that mass azithromycin distribution to preschool children reduced childhood mortality 1 . However, the large but simple trial design precluded determination of the mechanisms involved. Here we examined the gut microbiome of preschool children from 30 Nigerien communities randomized to either biannual azithromycin or placebo. Gut microbiome γ-diversity was not significantly altered ( P  = 0.08), but the relative abundances of two Campylobacter species, along with another 33 gut bacteria, were significantly reduced in children treated with azithromycin at the 24-month follow-up. Metagenomic analysis revealed functional differences in gut bacteria between treatment groups. Resistome analysis showed an increase in macrolide resistance gene expression in gut microbiota in communities treated with azithromycin ( P  = 0.004). These results suggest that prolonged mass azithromycin distribution to reduce childhood mortality reduces certain gut bacteria, including known pathogens, while selecting for antibiotic resistance. Mass antibiotic administration to preschool children in Nigerien communities alters the relative abundances of 35 bacterial species in the gut microbiome, including enteric pathogens, but also increases expression of macrolide resistance genes.
Antibiotic resistance profile of Campylobacter species recovered from some freshwater milieu in the Eastern Cape Province, South Africa
Background Freshwater is a major source of human waterborne infections caused by Campylobacter species. The extensive use of antibiotics is capable of causing the emergence and spread of Campylobacter strains that are resistant to the antibiotics, making campylobacteriosis more difficult to treat and persistent in the environment. This study evaluated the occurrence and antimicrobial resistance profiles of Campylobacter species in freshwater from the Eastern Cape Province, South Africa. Materials and methods Sixty-one freshwater samples were collected, yielding 302 presumptive Campylobacter isolates. PCR assays confirmed 78 isolates as belonging to Campylobacter species, identifying 35 (45%) as C. jejuni , 29 (37%) as C. coli , and 14 (18%) as C. lari . Antibiotic susceptibility testing was conducted to determine resistance patterns. Results The isolates showed high resistance to erythromycin (90%) and low resistance to gentamicin (11.58%). The most frequently observed resistance pattern was C-LEV-NA-AZM-CIP-AMP-IMI-GM-DO-S-TE-E for C. lari , C-LEV-NA-AZM-CIP-AMP-GM-DO-S-TE-E for C. jejuni , and C-LEV-NA-AZM-CIP-AMPI-GM-DO-TE-E for C. coli. (Chloramphenicol, Levofloxacin, Nalidixic acid, Azithromycin, Ciprofloxacin, Ampicillin, Imipenem, Gentamicin, Doxycycline, Streptomycin, Tetracycline, and Erythromycin). Most isolates had multiple antibiotic resistance (MAR) indices greater than 0.2. Genetic analysis revealed imipenem resistance genes ( bla IMP ) in 85.71% of isolates, followed by bla VIM (71.43%). The ermA gene was detected in only 4% of cases. The isolates tested negative for bla KPC , bla GES , ermC , and qnrA resistance genes. Conclusion The study shows that antimicrobial-resistant and potentially virulent Campylobacter strains are present in the freshwater environments in the Eastern Cape Province, posing a potential public health risk. However, surveillance systems and public awareness about campylobacteriosis and its transmission routes can reduce infection rates.
Diversity of Campylobacter spp. circulating in a rhesus macaque ( Macaca mulatta ) breeding colony using culture and molecular methods
Gastrointestinal disease is one of the most common reasons for hospitalization in non-human primate colonies and accounts for over one-third of non-research related euthanasia. In rhesus macaques, this manifests as both acute diarrhea and chronic enterocolitis (CE), a syndrome of chronic diarrhea resulting in poor weight gain or weight loss which is minimally responsive to treatment. Campylobacter spp. are major causes of acute enterocolitis in rhesus macaques and may predispose individuals to the development of CE, similar to post-infectious irritable bowel syndrome in humans. Despite these concerns, there are few studies characterizing Campylobacter in rhesus macaque colonies, in particular utilizing whole genome sequencing and assessing findings with respect to the health status of the host. Our findings provide insight into Campylobacter strains circulating in rhesus macaque colonies, which can improve clinical monitoring, assist in treatment decisions, and provide new avenues of investigation into campylobacteriosis as a catalyst for CE.
Clinical impact of the type VI secretion system on virulence of Campylobacter species during infection
Background The clinical course of Campylobacter infection varies in symptoms and severity depending on host factors, virulence of the pathogen and initiated therapy. The type VI secretion system (T6SS) has been identified as a novel virulence factor, which mediates contact-dependent injection of enzymes and toxins into competing bacteria or host cells and facilitates the colonisation of a host organism. We aimed to compare the clinical course of Campylobacter infection caused by strains with and without the T6SS and identify possible associations between this putative virulence factor and the clinical manifestations of disease. Methods From April 2015 to January 2017, patients with detection of Campylobacter spp. were identified at the University Hospital of Basel and the University Children’s Hospital of Basel and included in this case-control study. Presence of the T6SS gene cluster was assayed by PCR targeting the hcp gene, confirmed with whole genome sequencing. Pertinent clinical data was collected by medical record review. Differences in disease- and host-characteristics between T6SS-positive (case) and –negative (control) were compared in a uni- and multi-variable analysis. Hospital admission, antibiotic therapy, admission to intensive care unit, development of bacteraemia and in-hospital mortality were considered as clinical endpoints. Results We identified 138 cases of Campylobacter jejuni infections and 18 cases of Campylobacter coli infections from a paediatric and adult population. Analyses were focused on adult patients with C. jejuni ( n  = 119) of which 16.8% were T6SS-positive. Comparisons between T6SS-positive and -negative C. jejuni isolates did not reveal significant differences regarding clinical manifestations or course of disease. All clinical endpoints showed a similar distribution in both groups. A higher score in the Charlson Comorbidity Index was associated with T6SS-positive C. jejuni isolates ( p  < 0.001) and patients were more likely to have a solid organ transplant and to be under immunosuppressive therapy. Conclusions Our study does not provide evidence that T6SS is associated with a more severe clinical course. Interestingly, T6SS-positive isolates are more commonly found in immunocompromised patients: an observation which merits further investigation.
Population Genetics and Antimicrobial Susceptibility of Canine Campylobacter Isolates Collected before and after a Raw Feeding Experiment
In recent years, increasing numbers of consumers have become interested in feeding raw food for their pet dogs as opposed to commercial dry food, in the belief of health advantages. However, raw meat and internal organs, possibly contaminated by pathogens such as Campylobacter spp., may pose a risk of transmission of zoonoses to the pet owners. Campylobacter jejuni is the leading cause of bacterial gastroenteritis in humans but C. upsaliensis has also been associated with human disease. In this study we investigated the effect of different feeding strategies on the prevalence of Campylobacter spp. in Finnish dogs. We further characterized the isolates using multilocus sequence typing (MLST), whole-genome (wg) MLST and antimicrobial susceptibility testing. Dogs were sampled before and after a feeding period consisting of commercial raw feed or dry pellet feed. Altogether 56% (20/36) of the dogs yielded at least one Campylobacter-positive fecal sample. C. upsaliensis was the major species detected from 39% of the dogs before and 30% after the feeding period. Two C. jejuni isolates were recovered, both from raw-fed dogs after the dietary regimen. The isolates represented the same genotype (ST-1326), suggesting a common infection source. However, no statistically significant correlation was found between the feeding strategies and Campylobacter spp. carriage. The global genealogy of MLST types of dog and human C. upsaliensis isolates revealed weakly clonal population structure as most STs were widely dispersed. Major antimicrobial resistance among C. upsaliensis isolates was against streptomycin (STR MIC > 4 mg/l). Apart from that, all isolates were highly susceptible against the antimicrobials tested. Mutations were found in the genes rpsL or rpsL and rsmG in streptomycin resistant isolates. In conclusion, increasing trend to feed dogs with raw meat warrants more studies to evaluate the risk associated with raw feeding of pets in transmission of zoonoses to humans.
Prevalence and Antimicrobial Resistance of Campylobacter spp. Isolated from Poultry Carcasses in Poland
The purpose of the present study was to determine the prevalence of Campylobacter in poultry carcasses at slaughter in Poland. For the isolated strains, resistance to selected antibiotics and the associated genetic determinants were identified. A total of 498 Campylobacter isolates were obtained from 802 poultry samples during the 2-year study period. Strains were identified to species with the PCR method; 53.6% of the strains were Campylobacter jejuni and 46.4% were Campylobacter coli. A high percentage of the tested Campylobacter strains were resistant to ciprofloxacin and nalidixic acid (74.1 and 73.5%, respectively) followed by tetracycline (47.4%) and streptomycin (20.5%). Only one C. jejuni and two C. coli isolates were resistant to gentamicin. Seventy-nine (15.9%) of the 498 strains were resistant to three or more classes of antibiotics examined. Higher levels of resistance, irrespective of the antimicrobial agent tested, were found within the C. coli group. Almost all strains resistant to quinolones (99.5%) and to tetracycline (99.6%) carried the Thr-86-to-Ile mutation in the gyrA gene and possessed the tet(O) marker, respectively. All isolates resistant to erythromycin had the A2075G mutation in the 23S rRNA gene. These results reveal that poultry carcasses in Poland are a reservoir of potentially pathogenic and antimicrobial-resistant Campylobacter strains for humans, which may pose a public health risk.
Novel narrow spectrum benzyl thiophene sulfonamide derivatives to control Campylobacter
Campylobacter is a leading cause of bacterial foodborne gastroenteritis worldwide, and poultry are a major source of human campylobacteriosis. The control of Campylobacter from farm to fork is challenging due to emergence of microbial resistance and lack of effective control methods. We identified a benzyl thiophene sulfonamide based small molecule (compound 1) with a minimal inhibitory concentration (MIC) of 100 μM against Campylobacter jejuni 81–176 and Campylobacter coli ATCC33559, good drug-like properties, and low toxicity on eukaryotic cells. Compound 1 was used as a lead for the preparation of 13 analogues. Two analogues, compounds 4 and 8 (TH-4 and TH-8), were identified with better antimicrobial properties than compound 1. TH-4 and TH-8 had a MIC of 12.5 μM and 25 μM for C. coli and 50 μM and 100 μM for C. jejuni, respectively. Cytological studies revealed that both compounds affected C. jejuni envelope integrity. Further, both compounds had no effect on other foodborne pathogens. TH-4 and TH-8 had a minimal impact on the chicken cecal microbiota and were not toxic to colon epithelial cells and chicken macrophages, and red blood cells at 200 µM. Further, TH-4 and TH-8 reduced the Campylobacter load in chicken ceca (up to 2-log reduction) when infected chickens were orally treated for 5 days with 0.254 mg kg−1; as well as against internalized Campylobacter in Caco-2 cells at 12.5 µM and higher. Our study identified two novel specific and safe benzyl thiophene sulfonamide derivatives having potential for control of Campylobacter in chickens and humans.
Antimicrobial resistance and genomic characteristics of Campylobacter spp. From Australian meat chickens with A follow up investigation
The increasing resistance of bacteria to antimicrobials is a major threat to public health. This study investigates the prevalence of antimicrobial resistance, both phenotypic and genotypic, among Campylobacter isolates from Australian meat chickens in 2022, as a follow up to investigate trends since the last national surveillance undertaken in 2016. Isolates ( n  = 186) were obtained at slaughter from 200 pooled cecal samples taken from 1,000 meat chickens. The majority of C. jejuni (68.7%) and C. coli (88.9%) isolates were susceptible to all the antibiotics that were tested, and no multi-drug resistance was found. Resistance to ciprofloxacin (fluoroquinolone) was detected in 24.4% of the C. jejuni and 3.2% of the C. coli isolates. Whole genome sequencing revealed a diverse range of sequence types (STs). These included 32 previously reported STs for C. jejuni and 13 for C. coli , as well as four and seven previously undescribed STs for each species, respectively. The STs containing fluoroquinolone-resistant isolates were ST2083, ST10130, ST2895, ST7323, ST2398, and ST1078 for C. jejuni , and ST860 and ST894 for C. coli . Although fluoroquinolones are not used in animal production in Australia, resistance amongst C. jejuni isolates was high (24.4%). This finding emphasizes the need for enhanced surveillance and regular sampling along the food chain to understand the source of the isolates and to mitigate risks of antimicrobial resistance to protect public health.
A systematic review and meta-analysis reveal that Campylobacter spp. and antibiotic resistance are widespread in humans in sub-Saharan Africa
Campylobacter spp. are zoonotic bacteria that cause gastroenteritis in humans worldwide, whose main symptom is diarrhea. In certain cases, extra intestinal manifestations may occur, such as Guillain Barré syndrome. The bacteria cause severe diarrhea mostly in children and in immunocompromised individuals. This review aims to address the prevalence of Campylobacter spp. in humans in sub-Saharan Africa. It also aims to understand the impact of HIV in the prevalence, as well as to report data on antibiotic resistance and propose research priorities. We followed PRISMA guidelines to find studies on the occurrence of Campylobacter spp. in humans in all countries from sub-Saharan Africa. Studies published between 2000 and 2020 were searched in PubMed, Cochrane Library, CINAHL, African Index Medicus, African Journals Online, Google Scholar and Science Direct. We have conducted a random-effect meta-analysis and calculated the proportion of resistant isolates to different antibiotics. We found 77 studies that described such occurrence in humans in 20 out of 53 sub-Saharan African countries. Campylobacter jejuni was the most prevalent species. Pooled prevalence was 9.9% (CI: 8.4%-11.6%). No major variations within the different sub-regions were found. Most studies reported Campylobacter spp. as the cause of diarrhea, mainly in children. Some studies reported the bacteria as a possible etiologic agent of acute flaccid paralysis and urinary tract infection. Campylobacter spp. presented a higher pooled prevalence in HIV infected patients, although not statistically significant. High proportions of resistant strains were reported for many antibiotics, including erythromycin and tetracycline. Campylobacter spp. occur in sub-Saharan Africa, although information is scarce or inexistent for many countries. Research priorities should include investigation of the understudied species; extra intestinal manifestations; the impact of HIV infection and associated risk factors. Control strategies should be reinforced to contain the spread of this pathogen and drug resistance.