- Volume 1, Issue 2, 2019
Volume 1, Issue 2, 2019
- Editorial
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- Short Communication
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Phylogenomics insights into order and families of Lysobacterales
More LessOrder Lysobacterales (earlier known Xanthomonadales ) is a taxonomically complex group of a large number of gamma-proteobacteria classified in two different families, namely Lysobacteraceae and Rhodanobacteraceae . Current taxonomy is largely based on classical approaches and is devoid of whole-genome information-based analysis. In the present study, we have taken all classified and poorly described species belonging to the order Lysobacterales to perform a phylogenetic analysis based on the 16 S rRNA sequence. Moreover, to obtain robust phylogeny, we have generated whole-genome sequencing data of six type species namely Metallibacterium scheffleri , Panacagrimonas perspica , Thermomonas haemolytica , Fulvimonas soli , Pseudofulvimonas gallinarii and Rhodanobacter lindaniclasticus of the families Lysobacteraceae and Rhodanobacteraceae . Interestingly, whole-genome-based phylogenetic analysis revealed unusual positioning of the type species Pseudofulvimonas , Panacagrimonas , Metallibacterium and Aquimonas at family level. Whole-genome-based phylogeny involving 92 type strains resolved the taxonomic positioning by reshuffling the genus across families Lysobacteraceae and Rhodanobacteraceae . The present study reveals the need and scope for genome-based phylogenetic and comparative studies in order to address relationships of genera and species of order Lysobacterales .
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- Research Article
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Detection of different enteric viruses in children with diarrheal disease: evidence of the high frequency of mixed infections
More LessEnteric viruses play a major role in causing diarrhea in children. Early identification of the causative pathogen is still a challenge in the clinical laboratory. A multiplex PCR assay is a useful tool to screen a large number of clinical samples especially in an outbreak situation. In this study, a multiplex reverse transcription (RT)-PCR assay was developed to detect nine enteric viruses such as group A rotavirus, norovirus GGII, sapovirus, adenovirus, astrovirus, aichivirus, parechovirus, bocavirus and enterovirus in clinical samples of diarrheal cases. Stool samples (n=185) collected from infants and children with acute gastroenteritis cases in Pune, western India were analysed for nine different enteric viruses by currently developed multiplex RT- PCR. Predominance of group A rotavirus (76%) followed by enterovirus (11.5%), astrovirus (4.5%), adenovirus (2.7%) and norovirus GII (1.6%) was observed. A total of 44.8 % (82/185) samples analysed by this method showed high frequency of mixed infections. These results highlighted high prevalence and diversity of different enteric viruses in children. The multiplex PCR showed good concordance with monoplex RT-PCR for detection of these enteric viruses in clinical samples. This is the first report on the development of a multiplex RT-PCR assay for detection of multiple enteric viruses in diarrheal diseases from India.
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Serum separator tube method for matrix-assisted laser desorption/ionization time-of-flight analysis
More LessBackground. Without appropriate treatment, bloodstream infections have a high mortality rate. Quicker identification of the microbial pathogen allows the clinician to develop an initial strategy of antimicrobial therapy. Sample preparation protocols for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS; Bruker Daltonics for Microflex LT spectrometer) technology were evaluated in an attempt to identify pathogens directly from positive blood culture bottles and thus shorten the time to identify them. This application requires preparatory processing because blood culture bottles contain undesirable proteins. This study aimed to evaluate two methods for microbial preparation for identification by MALDI-ToF MS.
Methods. This study evaluated two methods for microbial preparation from 200 positive blood culture samples, half prepared by the differential centrifugation method and half with the serum separator tube method for identification by MALDI-ToF MS. Both methods were compared to conventional methods such as VITEK II and ChromAgar culture plates.
Results. All Gram-negative bacteria tested were identified correctly by MALDI-ToF MS compared to conventional methods, regardless of the preparation method. However, more Gram-positive bacteria were identified when the serum separator tube method was used (83.3%) compared with the differential centrifugation method (65.3 %). Moreover, the serum separator tube protocol requires 12–15 min, while the differential centrifugation protocol requires 30–45 min.
Conclusions. Sample preparation using the serum separator tube method is easy to perform, fast and reliable for accurate microbial identification by MALDI-ToF MS technology.
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Application of whole genome sequencing to query a potential outbreak of Elizabethkingia anophelis in Ontario, Canada
Bioinformatic analysis of whole genome sequence (WGS) data is emerging as a tool to provide powerful insights for clinical microbiology. We used WGS data to investigate the genetic diversity of clinical isolates of the bacterial pathogen Elizabethkingia anophelis to query the existence of a single-strain outbreak in Ontario, Canada. The Public Health Ontario Laboratory (PHOL) provides reference identification of clinical isolates of bacteria for Ontario and prior to 2016 had not identified E. anophelis . In the wake of the Wisconsin outbreak of 2015–2016 for which a source was never elucidated, the identification of E. anophelis from clinical specimens from five Ontario patients gave reason to question the presence of an outbreak. Genomic comparisons based on core genome multi-locus sequence typing conclusively refuted the existence of an outbreak, since the 5 Ontario isolates were genetically dissimilar, representing at least 3 distinct sub-lineages scattered among a set of 39 previously characterized isolates. Further interrogation of the genomic data revealed multiple antimicrobial resistance genes. Retrospective reidentification via rpoB sequence analysis of 22 clinical isolates of Elizabethkingia spp. collected by PHOL from 2010 to 2018 demonstrated that E. anophelis was isolated from clinical specimens as early as 2010. The uptick in E. anophelis in Ontario was not due to an outbreak or increased incidence of the pathogen, but rather enhanced laboratory identification techniques and improved sequence databases. This study demonstrates the usefulness of WGS analysis as a public health tool to quickly rule out the existence of clonally related case clusters of bacterial pathogens indicative of single-strain outbreaks.
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- Personal View
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Implementation of the Nagoya Protocol within the Collection of Institut Pasteur
More LessThe focus of the EU regulations on the Nagoya Protocol on Access and Benefit-Sharing leaves the control of access to genetic resources up to each member state. France has chosen to control access and is going to put in place regulations for it. All the materials received should have specific documentation regarding the accession of genetic resources, where there is a National Authority to issue them. The European commission will maintain a list of biological collections with registered status proposed by each country. The member states are responsible for considering inclusion and verification of these collections. In recent years, the Collection of Institut Pasteur (CIP) staff has expressed concern over how to interact with the implementation of the Nagoya Protocol in the collection but also at the national level with the aim that the CIP will be a registered collection. The advantage of accessing resources from a registered collection is that users of genetic resources will be considered as having exercised ‘due diligence’ if they source their genetic resources from these collections. This could facilitate the process for scientists when applying for research funding. The CIP organized the accession of new deposits and the distribution of micro-organisms in connection with it.
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- Case Report
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Novel gas producing Vibrio cholerae: a case report of gastroenteritis with acute kidney injury
Background. Bacterial characterization is important in clinical and epidemiological studies. We herein report the first case of gas-producing Vibrio cholera gastroenteritis with acute kidney injury.
Case presentation. A 30-year-old female presented to the emergency department with complaints of about ten episodes of watery diarrhea, four episodes of vomiting and elevated serum urea/creatinine levels. Although the bacteria were first misidentified as Vibrio furnissii by gas production on carbohydrate fermentation and triple sugar iron agar, it was later confirmed as Vibrio cholerae by 16 S rRNA gene sequencing and specific PCR. The treatment regimen was followed as for Vibrio species with intravenous fluids, ciprofloxacin and doxycycline. The patient recovered without relapse.
Conclusions. Literature survey from the PubMed database shows no gas-producing Vibrio cholerae isolate being reported in the world. Further, genotype studies are warranted to look into the gas production of Vibrio cholerae .
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Prevalence and resistance pattern of uropathogens from community settings of different regions: an experience from India
Sarita Mohapatra, Rajashree Panigrahy, Vibhor Tak, Shwetha J. V., Sneha K. C., Susmita Chaudhuri, Swati Pundir, Deepak Kocher, Hitender Gautam, Seema Sood, Bimal Kumar Das, Arti Kapil, Pankaj Hari, Arvind Kumar, Rajesh Kumari, Mani Kalaivani, Ambica R., Harshal Ramesh Salve, Sumit Malhotra and Shashi Kant
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