The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Celia M Manaia - One of the best experts on this subject based on the ideXlab platform.
-
bacterial lineages putatively associated with the dissemination of antibiotic resistance genes in a full scale urban wastewater treatment plant
Environment International, 2018Co-Authors: Carlos Narcisodarocha, Jaqueline Rocha, Ivone Vazmoreira, Felipe Lira, Javier Tamames, Isabel Henriques, Jose L Martinez, Celia M ManaiaAbstract:Abstract Urban wastewater treatment plants (UWTPs) are reservoirs of antibiotic resistance. Wastewater treatment changes the bacterial community and inevitably impacts the fate of antibiotic resistant bacteria and antibiotic resistance genes (ARGs). Some bacterial groups are major carriers of ARGs and hence, their elimination during wastewater treatment may contribute to increasing resistance removal efficiency. This study, conducted at a full-scale UWTP, evaluated variations in the bacterial community and ARGs loads and explored possible associations among them. With that aim, the bacterial community composition (16S rRNA gene Illumina sequencing) and ARGs abundance (real-time PCR) were characterized in samples of raw wastewater (RWW), secondary effluent (sTWW), after UV disinfection (tTWW), and after a period of 3 days storage to monitoring possible bacterial regrowth (tTWW-RE). Culturable enterobacteria were also enumerated. Secondary treatment was associated with the most dramatic bacterial community variations and coincided with reductions of ~2 log-units in the ARGs abundance. In contrast, no significant changes in the bacterial community composition and ARGs abundance were observed after UV disinfection of sTWW. Nevertheless, after UV treatment, viability losses were indicated ~2 log-units reductions of culturable enterobacteria. The analysed ARGs (qnrS, blaCTX-M, blaOXA-A, blaTEM, blaSHV, sul1, sul2, and intI1) were strongly correlated with taxa more abundant in RWW than in the other types of water, and which associated with humans and animals, such as members of the families Campylobacteraceae, Comamonadaceae, Aeromonadaceae, Moraxellaceae, and Bacteroidaceae. Further knowledge of the dynamics of the bacterial community during wastewater treatment and its relationship with ARGs variations may contribute with information useful for wastewater treatment optimization, aiming at a more effective resistance control.
Peter Vandamme - One of the best experts on this subject based on the ideXlab platform.
-
minimal standards for describing new species belonging to the families Campylobacteraceae and helicobacteraceae campylobacter arcobacter helicobacter and wolinella spp
International Journal of Systematic and Evolutionary Microbiology, 2017Co-Authors: William G Miller, Kurt Houf, James G Fox, Peter VandammeAbstract:Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant updates to previous minimal standards for describing new species of Campylobacteraceae and Helicobacteraceae. This paper is the result of these discussions and proposes minimum requirements for the description of new species belonging to the families Campylobacteraceae and Helicobacteraceae, thus including species in Campylobacter, Arcobacter, Helicobacter, and Wolinella. The core underlying principle remains the use of appropriate phenotypic and genotypic methods to characterise strains sufficiently so as to effectively and unambiguously determine their taxonomic position in these families, and provide adequate means by which the new taxon can be distinguished from extant species and subspecies. This polyphasic taxonomic approach demands the use of appropriate reference data for comparison to ensure the novelty of proposed new taxa, and the recommended study of at least five strains to enable species diversity to be assessed. Methodological approaches for phenotypic and genotypic (including whole-genome sequence comparisons) characterisation are recommended.
-
Taxonomy of the family Campylobacteraceae
Campylobacter Third Edition, 2008Co-Authors: Lies Debruyne, Dirk Gevers, Peter VandammeAbstract:This chapter presents an overview of the biological diversity of Campylobacter species and Arcobacter species and also addresses the taxonomic information that has become available through whole-genome sequence analysis. Classical biochemical tests routinely used for the identification of clinical bacteria often yielded negative or variable results within Campylobacter species. This poor biochemical reactivity and lack of clear-cut differential characters led to the wide application of vernacular names for many groups of Campylobacter-like organisms (CLOs). Some of the CLO groups were later classified as novel species, but several were identified as biochemical variants of well-known species. The first isolated Campylobacter was almost certainly Campylobacter fetus. In 1914, a researcher observed a vibrio, later classified as Vibrio sputorum, in sputum of a patient with bronchitis. Similar bacteria isolated from the bovine vagina and semen were classified as V. bubulus. During a study of the bacterial flora of the cloacae of whooping cranes, 10 atypical Campylobacter isolates were recovered on two separate occasions and were classified as C. canadensis. Strain NP4, isolated from groundwater with high arsenic concentrations, is classified as a Sulfurospirillum species on the basis of 16S rRNA gene sequence analysis, and it differs from the other Sulfurospirillum isolates in its carbon source and electron acceptor usage profiles. Representative strains of Bacteroides ureolyticus species were included in a polyphasic taxonomic study to elucidate their taxonomic status. Strains have been isolated from superficial ulcers and soft tissue infections, urethritis, vaginosis, and periodontal disease.
-
Occurrence and distribution of Arcobacter species in poultry processing.
Journal of food protection, 2002Co-Authors: Kurt Houf, Lieven De Zutter, Jan Van Hoof, Peter VandammeAbstract:A total of 16 broiler flocks slaughtered in the morning in eight Belgian poultry slaughterhouses were examined for the presence of Campylobacteraceae. In samples collected before and after chilling, the prevalence of arcobacters was found to be higher than the prevalence of thermophilic campylobacters, with the slaughter procedure used having no clear effect. Two slaughterhouses were selected for a detailed investigation of the occurrence and distribution of arcobacters. Sampling carried out before slaughter revealed that both Arcobacter butzleri and Arcobacter cryaerophilus were commonly present on the slaughter equipment in both plants. These findings indicate inadequate decontamination of the slaughterhouse environment and suggest potential Arcobacter contamination of broiler carcasses through the slaughter equipment. Even before evisceration, contamination levels of hundreds to several thousands of arcobacters per gram of neck skin were detected. It appears unlikely that contamination through slaughter equipment alone explains the high contamination levels found for poultry products. Arcobacters were not isolated from the 30 intestinal tracts sampled for each broiler flock examined. A. cryaerophilus was the only Arcobacter species recovered from the transport crate samples collected before and after washing. Arcobacter contamination during slaughter, either direct (from chicken intestinal content or feces) or indirect (from equipment), was not confirmed. The origin and the precise routes of contamination remain to be determined.
-
proposal for a new family Campylobacteraceae
International Journal of Systematic and Evolutionary Microbiology, 1991Co-Authors: Peter Vandamme, J De LeyAbstract:The genera Campylobacter, Arcobacter, Helicobacter, Wolinella, and “Flexispira” constitute, within the class Proteobacteria, a separate eubacterial lineage identified as rRNA superfamily VI. A considerable number of common genotypic and phenotypic features differentiate the genera Campylobacter and Arcobacter from the other members of this group. Therefore, we propose that the genera Campylobacter and Arcobacter should be included in a separate family, for which the name Campylobacteraceae is proposed.
Carlos Narcisodarocha - One of the best experts on this subject based on the ideXlab platform.
-
bacterial lineages putatively associated with the dissemination of antibiotic resistance genes in a full scale urban wastewater treatment plant
Environment International, 2018Co-Authors: Carlos Narcisodarocha, Jaqueline Rocha, Ivone Vazmoreira, Felipe Lira, Javier Tamames, Isabel Henriques, Jose L Martinez, Celia M ManaiaAbstract:Abstract Urban wastewater treatment plants (UWTPs) are reservoirs of antibiotic resistance. Wastewater treatment changes the bacterial community and inevitably impacts the fate of antibiotic resistant bacteria and antibiotic resistance genes (ARGs). Some bacterial groups are major carriers of ARGs and hence, their elimination during wastewater treatment may contribute to increasing resistance removal efficiency. This study, conducted at a full-scale UWTP, evaluated variations in the bacterial community and ARGs loads and explored possible associations among them. With that aim, the bacterial community composition (16S rRNA gene Illumina sequencing) and ARGs abundance (real-time PCR) were characterized in samples of raw wastewater (RWW), secondary effluent (sTWW), after UV disinfection (tTWW), and after a period of 3 days storage to monitoring possible bacterial regrowth (tTWW-RE). Culturable enterobacteria were also enumerated. Secondary treatment was associated with the most dramatic bacterial community variations and coincided with reductions of ~2 log-units in the ARGs abundance. In contrast, no significant changes in the bacterial community composition and ARGs abundance were observed after UV disinfection of sTWW. Nevertheless, after UV treatment, viability losses were indicated ~2 log-units reductions of culturable enterobacteria. The analysed ARGs (qnrS, blaCTX-M, blaOXA-A, blaTEM, blaSHV, sul1, sul2, and intI1) were strongly correlated with taxa more abundant in RWW than in the other types of water, and which associated with humans and animals, such as members of the families Campylobacteraceae, Comamonadaceae, Aeromonadaceae, Moraxellaceae, and Bacteroidaceae. Further knowledge of the dynamics of the bacterial community during wastewater treatment and its relationship with ARGs variations may contribute with information useful for wastewater treatment optimization, aiming at a more effective resistance control.
K D M Pintar - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of various campylobacter specific quantitative pcr qpcr assays for detection and enumeration of Campylobacteraceae in irrigation water and wastewater via a miniaturized most probable number qpcr assay
Applied and Environmental Microbiology, 2016Co-Authors: Graham Banting, Shannon L Braithwaite, Candis Scott, Jinyong Kim, Byeonghwa Jeon, Nicholas J Ashbolt, Norma J Ruecker, Lisa Tymensen, Jollin Charest, K D M PintarAbstract:ABSTRACT Campylobacter spp. are the leading cause of bacterial gastroenteritis worldwide, and water is increasingly seen as a risk factor in transmission. Here we describe a most-probable-number (MPN)–quantitative PCR (qPCR) assay in which water samples are centrifuged and aliquoted into microtiter plates and the bacteria are enumerated by qPCR. We observed that commonly used Campylobacter molecular assays produced vastly different detection rates. In irrigation water samples, detection rates varied depending upon the PCR assay and culture method used, as follows: 0% by the de Boer Lv1-16S qPCR assay, 2.5% by the Van Dyke 16S and Jensen glyA qPCR assays, and 75% by the Linton 16S endpoint PCR when cultured at 37°C. Primer/probe specificity was the major confounder, with Arcobacter spp. routinely yielding false-positive results. The primers and PCR conditions described by Van Dyke et al. (M. I. Van Dyke, V. K. Morton, N. L. McLellan, and P. M. Huck, J Appl Microbiol 109:1053–1066, 2010, http://dx.doi.org/10.1111/j.1365-2672.2010.04730.x) proved to be the most sensitive and specific for Campylobacter detection in water. Campylobacter occurrence in irrigation water was found to be very low ( 2 /100 ml, with incubation at 42°C required for reducing microbial growth competition from arcobacters. Overall, when Campylobacter prevalence and/or concentration in water is reported using molecular methods, considerable validation is recommended when adapting methods largely developed for clinical applications. Furthermore, combining MPN methods with molecular biology-based detection algorithms allows for the detection and quantification of Campylobacter spp. in environmental samples and is potentially suited to quantitative microbial risk assessment for improved public health disease prevention related to food and water exposures. IMPORTANCE The results of this study demonstrate the importance of assay validation upon data interpretation of environmental monitoring for Campylobacter when using molecular biology-based assays. Previous studies describing Campylobacter prevalence in Canada utilized primers that we have determined to be nonspecific due to their cross-amplification of Arcobacter spp. As such, Campylobacter prevalence may have been vastly overestimated in other studies. Additionally, the development of a quantitative assay described in this study will allow accurate determination of Campylobacter concentrations in environmental water samples, allowing more informed decisions to be made about water usage based on quantitative microbial risk assessment.
Isabel Henriques - One of the best experts on this subject based on the ideXlab platform.
-
bacterial lineages putatively associated with the dissemination of antibiotic resistance genes in a full scale urban wastewater treatment plant
Environment International, 2018Co-Authors: Carlos Narcisodarocha, Jaqueline Rocha, Ivone Vazmoreira, Felipe Lira, Javier Tamames, Isabel Henriques, Jose L Martinez, Celia M ManaiaAbstract:Abstract Urban wastewater treatment plants (UWTPs) are reservoirs of antibiotic resistance. Wastewater treatment changes the bacterial community and inevitably impacts the fate of antibiotic resistant bacteria and antibiotic resistance genes (ARGs). Some bacterial groups are major carriers of ARGs and hence, their elimination during wastewater treatment may contribute to increasing resistance removal efficiency. This study, conducted at a full-scale UWTP, evaluated variations in the bacterial community and ARGs loads and explored possible associations among them. With that aim, the bacterial community composition (16S rRNA gene Illumina sequencing) and ARGs abundance (real-time PCR) were characterized in samples of raw wastewater (RWW), secondary effluent (sTWW), after UV disinfection (tTWW), and after a period of 3 days storage to monitoring possible bacterial regrowth (tTWW-RE). Culturable enterobacteria were also enumerated. Secondary treatment was associated with the most dramatic bacterial community variations and coincided with reductions of ~2 log-units in the ARGs abundance. In contrast, no significant changes in the bacterial community composition and ARGs abundance were observed after UV disinfection of sTWW. Nevertheless, after UV treatment, viability losses were indicated ~2 log-units reductions of culturable enterobacteria. The analysed ARGs (qnrS, blaCTX-M, blaOXA-A, blaTEM, blaSHV, sul1, sul2, and intI1) were strongly correlated with taxa more abundant in RWW than in the other types of water, and which associated with humans and animals, such as members of the families Campylobacteraceae, Comamonadaceae, Aeromonadaceae, Moraxellaceae, and Bacteroidaceae. Further knowledge of the dynamics of the bacterial community during wastewater treatment and its relationship with ARGs variations may contribute with information useful for wastewater treatment optimization, aiming at a more effective resistance control.