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759 result(s) for "Campylobacter - classification"
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Campylobacter Genotyping to Determine the Source of Human Infection
Background. Campylobacter species cause a high proportion of bacterial gastroenteritis cases and are a significant burden on health care systems and economies worldwide; however, the relative contributions of the various possible sources of infection in humans are unclear. Methods. National-scale genotyping of Campylobacter species was used to quantify the relative importance of various possible sources of human infection. Multilocus sequence types were determined for 5674 isolates obtained from cases of human campylobacteriosis in Scotland from July 2005 through September 2006 and from 999 Campylobacter species isolates from 3417 contemporaneous samples from potential human infection sources. These data were supplemented with 2420 sequence types from other studies, representing isolates from a variety of sources. The clinical isolates were attributed to possible sources on the basis of their sequence types with use of 2 population genetic models, STRUCTURE and an asymmetric island model. Results. The STRUCTURE and the asymmetric island models attributed most clinical isolates to chicken meat (58% and 78% of Campylobacter jejuni and 40% and 56% of Campylobacter coli isolates, respectively), identifying it as the principal source of Campylobacter infection in humans. Both models attributed the majority of the remaining isolates to ruminant sources, with relatively few isolates attributed to wild bird, environment, swine, and turkey sources. Conclusions. National-scale genotyping was a practical and efficient methodology for the quantification of the contributions of different sources to human Campylobacter infection. Combined with the knowledge that retail chicken is routinely contaminated with Campylobacter, these results are consistent with the view that the largest reductions in human campylobacteriosis in industrialized countries will come from interventions that focus on the poultry industry.
Quadruplex qPCR for detection and discrimination of C. Coli,C. fetus, and C. Jejuni from other Campylobacter species in chicken and sheep meat
Campylobacter is gram-negative bacteria considered the predominant genera isolated from poultry samples and associated with gastroenteritis. Due to the problems in conventional cultural methods of time-consuming and technically demanding requirements, a rapid and feasible method for their identification and discrimination of the closely related spp. Including Campylobacter coli , Campylobacter fetus , and Campylobacter jejuni is needed. This study analyzes the chicken and sheep meats samples ( n  = 125) using culture and pre-enrichment-based Quadraplex real-time PCR by targeting OrfA, CstA , HipO , and 16 S rRNA genes of C. coli , C. fetus , C. jejuni and Campylobacter spp. Respectively. The analysis of 125 chicken and sheep meat samples by culture and real-time PCR showed high concordance between the results of the two methods. The present study show high prevalence of Campylobacter species (35% and 32% from chicken and meat respectively) of which C. jejuni were the most abundant. Reaction efficiencies were between 90 and 110%, and detect as low as 8.9 fg in C. jejuni . The need for quick detection and discrimination methods in sheep and chicken meat can be met using the described Quadraplex real-time PCR methodology.
Characterization of aquatic clade 2 and 3 Campylobacter coli isolates from Slovenia reveals admixture with other Campylobacter species
Campylobacter coli , a significant foodborne pathogen, has undergone extensive genetic exchange with its close relative, Campylobacter jejuni , leading to the emergence of three distinct clades. While clade 1 strains are commonly isolated from clinical and agricultural sources, clades 2 and 3 are primarily found in aquatic environments. This study aimed to enhance our understanding of C. coli clade 2 and 3 isolates through genomic and phenotypic characterization. A total of 48 surface water samples were collected from 19 different water bodies throughout Slovenia, and eleven Campylobacter isolates initially identified as C. coli from clades 2 and 3 were cultured. Whole genome sequencing was then performed on these isolates. Phylogenetic analysis was conducted using core genome multilocus sequence typing (cgMLST) and k-mer analysis. Phenotypic characterization included growth analysis, autoagglutination, biofilm formation, motility, antimicrobial susceptibility, water survival, and metabolic profiling. Genomic analysis revealed significant admixture with other Campylobacter species in the clade 2 and 3 isolates. One isolate was found to represent a new species related to C. coli . Besides C. jejuni and C. lari , this novel species appears to have contributed to introgression in the C. coli clades 2 and 3 isolates. Phenotypic characterization demonstrated diverse growth patterns, motility, autoagglutination abilities, and biofilm formation among the isolates. This study provides new insights into the genetic diversity and phenotypic characteristics of aquatic C. coli clade 2 and 3 isolates from Slovenia. The observed admixture with other Campylobacter species highlights the complex evolutionary history of these environmental strains and underscores the importance of continued surveillance and characterization of Campylobacter isolates from diverse ecological niches.
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.
Burden and epidemiology of Campylobacter species in acute enteritis cases in Burkina Faso
Background Campylobacter spp. is a significant etiological agent of bacterial gastroenteritis globally. In Burkina Faso (BFA), the actual impact of this pathogen on gastroenteritis is considerably underestimated, primarily due to inadequate surveillance systems. Objectives This study aimed to investigate the proportion of Campylobacter species responsible for acute gastroenteritis among patients of all ages in urban and rural areas of BFA, using molecular biology techniques. Study design & methods Between 2018 and 2021, faecal specimens were obtained from 1,295 individuals presenting with acute gastroenteritis. These samples underwent screening for the Campylobacter coli/jejuni/lari complex utilizing real-time polymerase chain reaction (PCR) assays. Subsequently, positive samples were subjected to species-level differentiation through the application of species-specific primers. Results Campylobacter spp. was detected in 25.0% (324/1,295) of the samples analysed. The majority of positive samples (95%, 308/324) were obtained from children under 5 years of age. Species identification was performed on a subset of 114 isolates, revealing 51 Campylobacter jejuni , 10 Campylobacter coli , and 53 Campylobacter isolates that remained unspeciated. Conclusions This study reveals a significant prevalence of Campylobacter species among patients with acute gastroenteritis, with a particularly high incidence observed in children under 5 years of age. Based on these findings, the implementation of routine Campylobacter surveillance in public health laboratories is strongly recommended to better monitor and address this health concern.
Rapid Detection and Differentiation of Campylobacter jejuni, Campylobacter coli, and Campylobacter lari in Food, Using Multiplex Real-Time PCR
A multiplex real-time PCR assay based on four differently labeled TaqMan probes for detection and differentiation of the thermophilic Campylobacter species C. jejuni, C. coli, and C. lari was established and validated in food products. This assay combines two previously published PCR assays for C. jejuni and C. coli with a newly developed detection assay for C. lari and an internal amplification control system. The selectivity of the method was determined by analyzing 70 Campylobacter strains and 43 strains of other bacteria. The sensitivity was 50 fg of C. jejuni and C. lari DNA and 500 fg of C. coli DNA per PCR. It was possible to detect 1 to 10 CFU/25 g of food before preenrichment of all three species. More than 400 samples of various foods (poultry, seafood, and meat) were analyzed after 48 h of preenrichment parallel to the conventional diagnostic method of culture and biochemical identification. Using the established real-time PCR assay, 55.4% of the samples were recognized as positive for thermophilic Campylobacter species, whereas with the conventional method only 40.3% of the samples were positive. The real-time PCR assay also detected contaminations with two different Campylobacter species in 32.6% of the analyzed poultry samples, a finding of epidemiological interest. Compared with the original PCR method, which was established for the differentiation of bacterial isolates of C. jejuni and C. coli, this new method also detects and distinguishes C. lari, was validated as an analytical tool for food analysis, and provides reliable and extensive results within 2 days.
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.
Sources of Human Campylobacteriosis Cases in Estonia and the Genomic Associations with Broiler Chicken Meat Isolates
This study used three complementary datasets to investigate the relationship between human Campylobacter infections in Estonia and potential sources. A targeted dataset of 15 C. jejuni genomes with overlapping sequence types from human cases and broiler chicken meat was analysed using genotyping and in silico antimicrobial resistance profiling, alongside 20 human isolates for source attribution. Additionally, 12,111 isolates were analysed to provide population-level context. The core genome multilocus sequence typing showed a high similarity (less than three allelic differences) between the human and broiler isolates of ST122, ST464, and ST7355, indicating poultry as a likely source, whereas ST9882 was more divergent (13–18 allelic differences). The resistance profiles were consistent within ST122, ST464, and ST7355, and all were resistant to ciprofloxacin, nalidixic acid, ampicillin, and tetracycline, while ST9882 additionally exhibited aminoglycoside (streptomycin) resistance. The source attribution linked 77.8% of the human cases to chicken and 22.2% to cattle. A novel genotype, ST11001, was identified in humans and attributed to cattle source, while C. coli isolates were linked to birds and sheep. Poultry dominated the larger dataset (87.3%). Gastroenteritis was the predominant clinical presentation (98.5%), whereas ST22 and ST122 were associated with Guillain–Barré syndrome. These findings support poultry as a major reservoir of human Campylobacter infections and highlight the need for coordinated cross-border surveillance.
High Prevalence of Resistance to Fluoroquinolones and Tetracycline Campylobacter Spp. Isolated from Poultry in Poland
Campylobacter spp. is a major cause of foodborne diseases in humans, particularly when transmitted by the handling or consumption of undercooked poultry meat. Most Campylobacter infections are self-limiting, but antimicrobial treatment ( e.g ., fluoroquinolones and macrolides) is necessary in severe or prolonged cases. The indiscriminate use of these drugs, both in clinical medicine and animal production, has a major impact on public health. The aim of the present study was to identify Campylobacter strains, isolated from turkey and broilers, using both PCR and the matrix-assisted laser desorption–ionization time-of-flight (MALDI-TOF) methods to reveal the accuracy of identification, as well to evaluate the antimicrobial and genetic resistance of the investigated strains. MALDI-TOF and PCR methods were used to show differences, if any, in the specificity of that test. In this study, MALDI-TOF mass spectrometry gave the same results as multiplex PCR, in all cases. The highest rate of resistance ( i.e ., 100% of turkey and broiler strains) was detected against ciprofloxacin, whereas 58.1% of turkey and 78.6% of broiler strains were resistant to tetracycline. Multidrug-resistant isolates were not found in the study. All ciprofloxacin-resistant strains had a mutation in the gyrA gene, at the Thr-86 position. The presence of the tetO gene was found in 71% of turkey and in 100% of broiler strains. All resistant to tetracycline strains included tetO gene. Additionally, in five turkey and three broiler strains, susceptible to tetracycline, tetO gene was present. These results indicate the high prevalence of Campylobacter strains, which are phenotypically and genetically resistant to fluoroquinolones and tetracycline.
Increased risk for Campylobacter jejuni and C. coli infection of pet origin in dog owners and evidence for genetic association between strains causing infection in humans and their pets
We compared Campylobacter jejuni/coli multilocus sequence types (STs) from pets (dogs/cats) and their owners and investigated risk factors for pet-associated human campylobacteriosis using a combined source-attribution and case-control analysis. In total, 132/687 pet stools were Campylobacter-positive, resulting in 499 strains isolated (320 C. upsaliensis/helveticus, 100 C. jejuni, 33 C. hyointestinalis/fetus, 10 C. lari, 4 C. coli, 32 unidentified). There were 737 human and 104 pet C. jejuni/coli strains assigned to 154 and 49 STs, respectively. Dog, particularly puppy, owners were at increased risk of infection with pet-associated STs. In 2/68 cases vs. 0·134/68 expected by chance, a pet and its owner were infected with an identical ST (ST45, ST658). Although common sources of infection and directionality of transmission between pets and humans were unknown, dog ownership significantly increased the risk for pet-associated human C. jejuni/coli infection and isolation of identical strains in humans and their pets occurred significantly more often than expected.