scholarly journals Recovery of Salmonella from biofilms in a headwater spring ecosystem

2011 ◽  
Vol 9 (3) ◽  
pp. 458-466 ◽  
Author(s):  
James P. Gaertner ◽  
Joseph A. Mendoza ◽  
Michael R. J. Forstner ◽  
Dittmar Hahn
Keyword(s):  
Pathogenic Bacteria ◽  
Chain Reaction ◽  
Selective Enrichment ◽  
Animal Wastes ◽  
San Marcos ◽  
Polymerase Chain ◽  
Spring Lake ◽  
Precipitation Events

Salmonellae are pathogenic bacteria often detected in waters impacted by human or animal wastes. In order to assess the fate of salmonellae in supposedly pristine environments, water and natural biofilm samples along with snails (Tarebia granifera) and crayfish (Procambarus clarkia) were collected before and up to 7 days following four precipitation events from sites within the headwater springs of Spring Lake, San Marcos, TX. The samples were analyzed for the presence of salmonellae by polymerase chain reaction (PCR) after semi-selective enrichment. Salmonellae were detected in one water sample directly after precipitation only, while detection in ten biofilm and two crayfish samples was not related to precipitation. Salmonellae were not detected in snails. Characterization of isolates by rep-PCR revealed shared profiles in water and biofilm samples, biofilm and crayfish samples, and biofilm samples collected 23 days apart. These results suggest that salmonellae are infrequently washed into this aquatic ecosystem during precipitation runoff and can potentially take up residency in biofilms which can help facilitate subsequent long-term persistence and eventual transfer through the food chain.

scholarly journals Temporal analyses of Salmonellae in a headwater spring ecosystem reveals the effects of precipitation and runoff events

2008 ◽  
Vol 7 (1) ◽  
pp. 115-121 ◽  
Author(s):  
James P. Gaertner ◽  
Tiffany Garres ◽  
Jesse C. Becker ◽  
Maria L. Jimenez ◽  
Michael R. J. Forstner ◽  
...  
Keyword(s):  
Molecular Techniques ◽  
Precipitation Event ◽  
Rainfall Events ◽  
Before And After ◽  
San Marcos ◽  
Polymerase Chain ◽  
Spring Lake ◽  
Events Detection ◽  
Precipitation Events

Sediments and water from the spring and slough arm of Spring Lake, the pristine headwaters of the San Marcos River, Texas, were analyzed for Salmonellae by culture and molecular techniques before and after three major precipitation events, each with intermediate dry periods. Polymerase chain reaction (PCR)-assisted analyses of enrichment cultures detected Salmonellae in samples after all three precipitation events, but failed to detect them immediately prior to the rainfall events. Detection among individual locations differed with respect to the precipitation event analyzed, and strains isolated were highly variable with respect to serovars. These results demonstrate that rainwater associated effects, most likely surface runoff, provide an avenue for short-term pollution of aquatic systems with Salmonellae that do not, however, appear to establish for the long-term in water nor sediments.

scholarly journals Detection of Salmonella in the intestine of Hypostomus plecostomus from the upper San Marcos River, Texas

2018 ◽  
Vol 16 (3) ◽  
pp. 460-471
Author(s):  
Anna Y. Gates ◽  
Trina M. Guerra ◽  
Fritzina B. Morrison ◽  
Michael R. J. Forstner ◽  
Thomas B. Hardy ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Sampling Period ◽  
Selective Enrichment ◽  
Fish Intestine ◽  
San Marcos ◽  
Element Sequence ◽  
Sampling Event ◽  
Sampling Times ◽  
Precipitation Events

Abstract The prevalence of salmonellae in the intestines of the invasive suckermouth catfish Hypostomus plecostomus was assessed in the San Marcos River, just down-stream of its spring-fed headwaters. In 2014, H. plecostomus, sediment, and water samples were collected during 15 sampling events. A combination of semi-selective enrichment and quantitative polymerase chain reaction (qPCR) revealed the presence of salmonellae in 45% of the fish intestines across the entire year, with a prevalence range of 13–100% per sampling event. Repetitive element sequence-based PCR (rep-PCR) and multi-locus sequence typing (MLST) revealed a high diversity of salmonellae from fish intestine samples at individual sampling times, single or multiple presence of rep-PCR patterns and serotypes within individual fish, and identical rep-PCR patterns and serotypes for different fish within and across sampling events. Overall, 15 serotypes were identified by MLST, with a diversity range between one and seven serotypes per sampling event. Some serotypes were retrieved only once, while others were detected more frequently. A few serotypes were retrieved at several sampling times, nearly evenly distributed over the entire sampling period. Prevalence and diversity were independent of precipitation events, indicating the potential presence of environmental strains that are capable of long-term persistence in the environment.

scholarly journals Molecular Characterization of Microbiota Associated With Sperm of Malaysian Mahseer Tor tambroides

2019 ◽  
Vol 15 ◽  
pp. 117693431985082
Author(s):  
Ivan Chong Chu Koh ◽  
Bin Hassan Badrul Nizam ◽  
Yazid Muhammad Abduh ◽  
Ambok Bolong Abol Munafi ◽  
Shumpei Iehata
Keyword(s):  
Gel Electrophoresis ◽  
Pathogenic Bacteria ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Sperm Quality ◽  
Good Prospect ◽  
Chain Reaction ◽  
Gradient Gel Electrophoresis ◽  
Polymerase Chain ◽  
Staphylococcus Spp

Malaysian Mahseer ( Tor tambroides) is considered as a good prospect for aquaculture in Malaysia. However, knowledge about Malaysian Mahseer-associated sperm microbiota is still limited, although some studies reported that sperm-related bacteria are a factor in the decline of sperm quality, as sperm may become the carrier of pathogenic bacteria to the egg. The goal of this study was to evaluate the sperm microbiota associated with Malaysian Mahseer from 3 different locations (Universiti Malaysia Terengganu [UMT], Ajil, and Pahang) using polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting and to compare location differences by cluster analysis. Our results showed that the UMT sample had different sperm microbiota composition and a different trend in its relationship with sperm quality. Correlation analysis showed a relationship between bacterial diversity and sperm quality. Phylogenetic analysis indicated that sperm microbiota was composed of diverse phyla, including Proteobacteria, Firmicutes, and Actinobacteria. Interestingly, bacteria such as Salinisphaera sp., Pelomonas sp., and Staphylococcus spp. were detected in all the locations, suggesting that these bacteria are indigenous bacterial members of the Malaysian Mahseer sperm microbiota, although their function is still unclear.

scholarly journals Acceptance of a Symptom-Based Approach for COVID-19 rtRT-PCR Testing to Conserve Resources in a Lower Middle-Income Setting

2021 ◽  
Vol 12 ◽  
pp. 215013272098771
Author(s):  
S. M. Rashed Ul Islam ◽  
Tahmina Akther ◽  
Md. Abdullah Omar Nasif ◽  
Sharmin Sultana ◽  
Saif Ullah Munshi
Keyword(s):  
Primary Method ◽  
Chain Reaction ◽  
Middle Income ◽  
Clinical Recovery ◽  
Clinical Presentations ◽  
Long Time ◽  
Nasopharyngeal Secretion ◽  
Polymerase Chain ◽  
Set Up

SARS-CoV-2 initially emerged in Wuhan, China in late 2019. It has since been recognized as a pandemic and has led to great social and economic disruption globally. The Reverse Transcriptase Real-Time Polymerase Chain Reaction (rtRT-PCR) has become the primary method for COVID-19 testing worldwide. The method requires a specialized laboratory set up. Long-term persistence of SARS-CoV-2 RNA in nasopharyngeal secretion after full clinical recovery of the patient is regularly observed nowadays. This forces the patients to spend a longer period in isolation and test repeatedly to obtain evidence of viral clearance. Repeated COVID-19 testing in asymptomatic or mildly symptomatic cases often leads to extra workload for laboratories that are already struggling with a high specimen turnover. Here, we present 5 purposively selected cases with different patterns of clinical presentations in which nasopharyngeal shedding of SARS-CoV-2 RNA was observed in patients for a long time. From these case studies, we emphasized the adoption of a symptom-based approach for discontinuing transmission-based precautions over a test-based strategy to reduce the time spent by asymptomatic and mildly symptomatic COVID-19 patients in isolation. A symptom-based approach will also help reduce laboratory burden for COVID-19 testing as well as conserve valuable resources and supplies utilized for rtRT-PCR testing in an emerging lower-middle-income setting. Most importantly, it will also make room for critically ill COVID-19 patients to visit or avail COVID-19 testing at their convenience.

scholarly journals Characterization of a new human apolipoprotein A-I Yame by direct sequencing of polymerase chain reaction-amplified DNA.

1991 ◽  
Vol 32 (8) ◽  
pp. 1275-1280
Author(s):  
Y Takada ◽  
J Sasaki ◽  
M Seki ◽  
S Ogata ◽  
Y Teranishi ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Direct Sequencing ◽  
Chain Reaction ◽  
Human Apolipoprotein ◽  
Apolipoprotein A ◽  
Polymerase Chain

scholarly journals Characterization of Xanthomonas axonopodis pv. phaseoli isolates

2008 ◽  
Vol 34 (3) ◽  
pp. 228-231 ◽  
Author(s):  
Willian Mário de Carvalho Nunes ◽  
Maria Júlia Corazza ◽  
Silvana Aparecida Crestes Dias de Souza ◽  
Siu Mui Tsai ◽  
Eiko Eurya Kuramae
Keyword(s):  
Xanthomonas Campestris ◽  
Random Amplified Polymorphic Dna ◽  
Hypersensitive Reaction ◽  
Chain Reaction ◽  
Xanthomonas Axonopodis ◽  
Paulo State ◽  
Total Dna ◽  
Polymerase Chain ◽  
Bacterial Plant Pathogen

A simple, quick and easy protocol was standardized for extraction of total DNA of the bacteria Xanthomonas axonopodis pv. phaseoli. The DNA obtained by this method had high quality and the quantity was enough for the Random Amplified Polymorphic DNA (RAPD) reactions with random primers, and Polymerase Chain Reaction (PCR) with primers of the hypersensitivity and pathogenicity gene (hrp). The DNA obtained was free of contamination by proteins or carbohydrates. The ratio 260nm/380nm of the DNA extracted ranged from 1.7 to 1.8. The hrp gene cluster is required by bacterial plant pathogen to produce symptoms on susceptible hosts and hypersensitive reaction on resistant hosts. This gene has been found in different bacteria as well as in Xanthomonas campestris pv. vesicatoria (9). The primers RST21 and RST22 (9) were used to amplify the hrp gene of nine different isolates of Xanthomonas axonopodis pv. phaseoli from Botucatu, São Paulo State, Brazil, and one isolate, "Davis". PCR amplified products were obtained in all isolates pathogenic to beans.

Characterization of Giardia duodenalis by polymerase-chain-reaction fingerprinting

1998 ◽  
Vol 84 (9) ◽  
pp. 707-714 ◽  
Author(s):  
Wieger L. Homan ◽  
Margriet Gilsing ◽  
Hafida Bentala ◽  
Louis Limper ◽  
Frans van Knapen
Keyword(s):  
Polymerase Chain Reaction ◽  
Giardia Duodenalis ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals Rhodococcus equi Infections in Goats: Characterization of Virulence Plasmids

2017 ◽  
Vol 55 (2) ◽  
pp. 273-276 ◽  
Author(s):  
Lauren W. Stranahan ◽  
Quinci D. Plumlee ◽  
Sara D. Lawhon ◽  
Noah D. Cohen ◽  
Laura K. Bryan
Keyword(s):  
Polymerase Chain Reaction ◽  
Lymph Nodes ◽  
Rhodococcus Equi ◽  
Caseous Lymphadenitis ◽  
Chain Reaction ◽  
Disseminated Infection ◽  
Virulence Plasmids ◽  
Visceral Organs ◽  
Polymerase Chain

Rhodococcus equi is an uncommon cause of systemic pyogranulomatous infections in goats with macroscopic similarities to caseous lymphadenitis caused by Corynebacterium pseudotuberculosis. Caprine cases have previously been reported to be caused by avirulent R. equi strains. Six cases of R. equi infection in goats yielding 8 R. equi isolates were identified from 2000 to 2017. Lesions varied from bronchopneumonia, vertebral and humeral osteomyelitis, and subcutaneous abscesses, to disseminated infection involving the lungs, lymph nodes, and multiple visceral organs. Isolates of R. equi from infected goats were analyzed by polymerase chain reaction for R. equi virulence-associated plasmid ( vap) genes. Seven of 8 isolates carried the VapN plasmid, originally characterized in bovine isolates, while 1 isolate lacked virulence plasmids and was classified as avirulent. The VapN plasmid has not been described in isolates cultured from goats.

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