scholarly journals Multilocus Sequence Typing and FlaA Sequencing Reveal the Genetic Stability of Campylobacter jejuni Enrichment during Coculture with Acanthamoeba polyphaga

2013 ◽  
Vol 79 (7) ◽  
pp. 2477-2479 ◽  
Author(s):  
Petra Griekspoor ◽  
Jenny Olofsson ◽  
Diana Axelsson-Olsson ◽  
Jonas Waldenström ◽  
Björn Olsen
Keyword(s):  
Campylobacter Jejuni ◽  
Genetic Stability ◽  
Environmental Samples ◽  
Molecular Techniques ◽  
Acanthamoeba Polyphaga ◽  
Culture Methods ◽  
Content Type ◽  
Conventional Culture ◽  
Low Concentrations ◽  
Genetic Specificity

ABSTRACTLow concentrations ofCampylobacter jejunicells in environmental samples make them difficult to study with conventional culture methods. Here, we show that enrichment by amoeba cocultures works well with low-concentration samples and that this method can be combined with molecular techniques without loss of genetic specificity.

scholarly journals Direct detection of Mycobacterium avium in environmental water and scale samples by loop-mediated isothermal amplification

2013 ◽  
Vol 12 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Yukiko Nishiuchi ◽  
Aki Tamaru ◽  
Yasuhiko Suzuki ◽  
Seigo Kitada ◽  
Ryoji Maekura ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Environmental Samples ◽  
Direct Detection ◽  
Culture Method ◽  
Environmental Water ◽  
Isothermal Amplification ◽  
Lamp Method ◽  
Culture Methods ◽  
Loop Mediated Isothermal Amplification ◽  
Conventional Culture

We previously demonstrated the colonization of Mycobacterium avium complex in bathrooms by the conventional culture method. In the present study, we aimed to directly detect M. avium organisms in the environment using loop-mediated isothermal amplification (LAMP), and to demonstrate the efficacy of LAMP by comparing the results with those obtained by culture. Our data showed that LAMP analysis has detection limits of 100 fg DNA/reaction for M. avium. Using an FTA® elute card, DNA templates were extracted from environmental samples from bathrooms in the residences of 29 patients with pulmonary M. avium disease. Of the 162 environmental samples examined, 143 (88%) showed identical results by both methods; 20 (12%) and 123 (76%) samples were positive and negative, respectively, for M. avium. Of the remaining 19 samples (12%), seven (5%) and 12 (7%) samples were positive by the LAMP and culture methods, respectively. All samples that contained over 20 colony forming units/primary isolation plate, as measured by the culture method, were also positive by the LAMP method. Our data demonstrate that the combination of the FTA elute card and LAMP can facilitate prompt detection of M. avium in the environment.

Rapid, Specific Detection of Salmonella Enteritidis in Pooled Eggs by Real-Time PCR

2004 ◽  
Vol 67 (5) ◽  
pp. 864-869 ◽  
Author(s):  
K. H. SEO ◽  
I. E. VALENTIN-BON ◽  
R. E. BRACKETT ◽  
P. S. HOLT
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Salmonella Enteritidis ◽  
Culture Method ◽  
Specific Detection ◽  
Culture Methods ◽  
Conventional Culture ◽  
Low Concentrations ◽  
Pcr Method ◽  
Group D

An assay was developed for the specific detection of Salmonella Enteritidis in eggs with the use of an application of the fluorogenic 5′ nuclease assay (TaqMan). In this assay, a segment of the gene sefA specific to Salmonella group D strains such as Salmonella Enteritidis was used. The amplification of the target gene products was monitored in real-time by incorporating a fluorescent dye–labeled gene-specific probe in the PCR reaction. This method correctly detected and distinguished Salmonella Enteritidis from nearly 50 of non–group D Salmonella and other non- Salmonella strains. Detection of the sefA gene was linear for DNA extracted from approximately 102 to 109 CFU/ml in phosphate-buffered saline and 103 to 108 CFU/ml in raw egg. In two trials, when applied to detection of Salmonella Enteritidis in homogenized egg pools and compared with conventional culture methods, the newly developed PCR method yielded a 100% correlation with results obtained by a conventional culture method. However, the PCR method required only 2 days, compared to the 5 days required by the culture method. The sensitivity of this assay was approximately less than 1 CFU/600 g of egg pool. The real-time PCR assay proved to be a rapid, highly sensitive test for detection and quantification of low concentrations of Salmonella Enteritidis in egg samples.

scholarly journals Rapid Filter-Based Detection and Culture of Burkholderia pseudomallei from Small Volumes of Urine

2017 ◽  
Vol 55 (9) ◽  
pp. 2698-2707 ◽  
Author(s):  
Pierre A. Michel ◽  
Christine Lascols ◽  
Jay E. Gee ◽  
Linda M. Weigel ◽  
David Sue
Keyword(s):  
Laboratory Testing ◽  
Burkholderia Pseudomallei ◽  
Dna Isolation ◽  
Urine Culture ◽  
Colony Growth ◽  
Detection Sensitivity ◽  
Culture Methods ◽  
Content Type ◽  
New Methods ◽  
Low Concentrations

ABSTRACTClinical outcomes of melioidosis patients improve when the infecting agent,Burkholderia pseudomallei, is rapidly detected and identified by laboratory testing. Detection ofB. pseudomalleiDNA or recovery of the pathogen by culture from urine can support a diagnosis of melioidosis and guide patient care. Two new methods, designated filter-capture DNA isolation (FCDI) and filter cellular recovery (FCR), were developed to increase the sensitivity of detection and recovery of viableB. pseudomalleicells from small volumes (0.45 ml) of urine. DNA from eight strains ofB. pseudomalleithat were spiked into synthetic urine at low concentrations (1 × 102CFU/ml) was detected in FCDI cell lysates using real-time PCR with greater consistency than with preparations from a QIAamp DNA Blood minikit. The FCR method showed greaterB. pseudomalleidetection sensitivity than conventional urine culture methods and resulted in typical colony growth at 24 h from as few as 1 × 102CFU/ml. In addition, the FCR method does not rely on precipitation of a urine pellet by centrifugation and requires a smaller volume of urine. The FCDI and FCR methods described here could improve time-to-results and decrease the number of negativeB. pseudomalleireports that are currently observed from urine culture as a consequence of samples containing low or variable bacterial cell concentrations.

scholarly journals CmeABC Multidrug Efflux Pump Contributes to Antibiotic Resistance and Promotes Campylobacter jejuni Survival and Multiplication in Acanthamoeba polyphaga

2017 ◽  
Vol 83 (22) ◽  
Author(s):  
Ana Vieira ◽  
Amritha Ramesh ◽  
Alan M. Seddon ◽  
Andrey V. Karlyshev
Keyword(s):  
Antibiotic Resistance ◽  
Campylobacter Jejuni ◽  
Molecular Mechanisms ◽  
Bacterial Resistance ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Microbial Pathogens ◽  
Bacterial Survival ◽  
Acanthamoeba Polyphaga ◽  
Content Type

ABSTRACT Campylobacter jejuni is a foodborne pathogen that is recognized as the leading cause of human bacterial gastroenteritis. The widespread use of antibiotics in medicine and in animal husbandry has led to an increased incidence of antibiotic resistance in Campylobacter. In addition to a role in multidrug resistance (MDR), the Campylobacter CmeABC resistance-nodulation-division (RND)-type efflux pump may be involved in virulence. As a vehicle for pathogenic microorganisms, the protozoan Acanthamoeba is a good model for investigations of bacterial survival in the environment and the molecular mechanisms of pathogenicity. The interaction between C. jejuni 81-176 and Acanthamoeba polyphaga was investigated in this study by using a modified gentamicin protection assay. In addition, a possible role for the CmeABC MDR pump in this interaction was explored. Here we report that this MDR pump is beneficial for the intracellular survival and multiplication of C. jejuni in A. polyphaga but is dispensable for biofilm formation and motility. IMPORTANCE The endosymbiotic relationship between amoebae and microbial pathogens may contribute to persistence and spreading of the latter in the environment, which has significant implications for human health. In this study, we found that Campylobacter jejuni was able to survive and to multiply inside Acanthamoeba polyphaga; since these microorganisms can coexist in the same environment (e.g., on poultry farms), the latter may increase the risk of infection with Campylobacter. Our data suggest that, in addition to its role in antibiotic resistance, the CmeABC MDR efflux pump plays a role in bacterial survival within amoebae. Furthermore, we demonstrated synergistic effects of the CmeABC MDR efflux pump and TetO on bacterial resistance to tetracycline. Due to its role in both the antibiotic resistance and the virulence of C. jejuni, the CmeABC MDR efflux pump could be considered a good target for the development of antibacterial drugs against this pathogen.

scholarly journals Waterborne Isolates of Campylobacter jejuni Are Able to Develop Aerotolerance, Survive Exposure to Low Temperature, and Interact With Acanthamoeba polyphaga

2021 ◽  
Vol 12 ◽  
Author(s):  
Ekaterina Shagieva ◽  
Katerina Demnerova ◽  
Hana Michova
Keyword(s):  
Low Temperature ◽  
Campylobacter Jejuni ◽  
Clinical Sample ◽  
Lethal Dose ◽  
Tetracycline Resistance ◽  
Environmental Parameters ◽  
Acanthamoeba Polyphaga ◽  
Culture Methods ◽  
Microaerobic Conditions ◽  
The Impact

Campylobacter jejuni is regarded as the leading cause of bacterial gastroenteritis around the world. Even though it is generally considered to be a sensitive microaerobic pathogen, it is able to survive in the environment outside of the intestinal tract of the host. This study aimed to assess the impact of selected environmental parameters on the survival of 14 C. jejuni isolates of different origins, including 12 water isolates. The isolates were tested for their antibiotic resistance, their ability to survive at low temperature (7°C), develop aerotolerance, and to interact with the potential protozoan host Acanthamoeba polyphaga. The antibiotic susceptibility was determined by standard disk diffusion according to EUCAST. Out of the 14 isolates, 8 were resistant to ciprofloxacin (CIP) and 5 to tetracycline (TET), while only one isolate was resistant to erythromycin (ERY). Five isolates were resistant to two different antibiotic classes. Tetracycline resistance was only observed in isolates isolated from wastewater and a clinical sample. Further, the isolates were tested for their survival at 7°C under both aerobic and microaerobic conditions using standard culture methods. The results showed that under microaerobic conditions, all isolates maintained their cultivability for 4 weeks without a significant decrease in the numbers of bacteria and variation between the isolates. However, significant differences were observed under aerobic conditions (AC). The incubation led to a decrease in the number of cultivable cells, with complete loss of cultivability after 2 weeks (one water isolate), 3 weeks (7 isolates), or 4 weeks of incubation (6 isolates). Further, all isolates were studied for their ability to develop aerotolerance by repetitive subcultivation under microaerobic and subsequently AC. Surprisingly, all isolates were able to adapt and grow under AC. As the last step, 5 isolates were selected to evaluate a potential protective effect provided by A. polyphaga. The cocultivation of isolates with the amoeba resulted in the survival of about 40% of cells treated with an otherwise lethal dose of gentamicin. In summary, C. jejuni is able to adapt and survive in a potentially detrimental environment for a prolonged period of time, which emphasizes the role of the environmental transmission route in the spread of campylobacteriosis.

scholarly journals Comparison of Loop-Mediated Isothermal Amplification Assay and Conventional Culture Methods for Detection of Campylobacter jejuni and Campylobacter coli in Naturally Contaminated Chicken Meat Samples

2009 ◽  
Vol 75 (6) ◽  
pp. 1597-1603 ◽  
Author(s):  
Wataru Yamazaki ◽  
Masumi Taguchi ◽  
Takao Kawai ◽  
Kentaro Kawatsu ◽  
Junko Sakata ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Lamp Assay ◽  
Chicken Meat ◽  
Isothermal Amplification ◽  
Campylobacter Coli ◽  
Culture Methods ◽  
Culture Test ◽  
Loop Mediated Isothermal Amplification ◽  
Conventional Culture ◽  
Meat Samples

ABSTRACT We investigated the efficacy of a loop-mediated isothermal amplification (LAMP) assay for detection of chicken meat samples naturally contaminated with Campylobacter jejuni and Campylobacter coli. A total of 144 Preston enrichment broth cultures from chicken meat samples were assessed by using the LAMP assay and conventional culture methods, which consist of a combination of Preston enrichment culturing and plating onto Butzler and modified charcoal cefoperazone deoxycholate agars. Compared with C. jejuni-C. coli isolation using the conventional culture test, the LAMP results showed 98.5% (67/68) and 97.4% (74/76) sensitivity and specificity, respectively, and the positive and negative predictive values were 97.1% (67/69) and 98.7% (74/75), respectively. The conventional culture test required more than 3 to 4 days to isolate and identify C. jejuni and C. coli in the Preston enrichment cultures. In contrast, the LAMP assay was markedly faster, requiring less than 90 min from the beginning of DNA extraction to final detection and differentiation of C. jejuni and C. coli. In total, the LAMP assay required 23.5 to 25.5 h from the beginning of the enrichment culture to final determination. These results suggest that our LAMP assay is a powerful tool for rapid, sensitive, and practical detection of C. jejuni and C. coli which may facilitate surveillance and control of C. jejuni-C. coli contamination in chicken, as well as investigations of food poisoning incidents caused by these organisms. This is the first report of a highly sensitive and specific LAMP assay to detect and differentiate C. jejuni and C. coli in chicken meat samples.

scholarly journals Evaluation of Molecular Methods To Improve the Detection of Burkholderia pseudomallei in Soil and Water Samples from Laos

2015 ◽  
Vol 81 (11) ◽  
pp. 3722-3727 ◽  
Author(s):  
Michael Knappik ◽  
David A. B. Dance ◽  
Sayaphet Rattanavong ◽  
Alain Pierret ◽  
Olivier Ribolzi ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Samples ◽  
Environmental Samples ◽  
Burkholderia Pseudomallei ◽  
Molecular Detection ◽  
Culture Methods ◽  
Environmental Distribution ◽  
Content Type ◽  
Culture Techniques ◽  
Enrichment Step

ABSTRACTBurkholderia pseudomalleiis the cause of melioidosis, a severe and potentially fatal disease of humans and animals. It is endemic in northern Australia and Southeast Asia and is found in soil and surface water. The environmental distribution ofB. pseudomalleiworldwide and within countries where it is endemic, such as the Lao People's Democratic Republic (Laos), remains unclear. However, this knowledge is important to our understanding of the ecology and epidemiology ofB. pseudomalleiand to facilitate public health interventions. Sensitive and specific methods to detectB. pseudomalleiin environmental samples are therefore needed. The aim of this study was to compare molecular and culture-based methods for the detection ofB. pseudomalleiin soil and surface water in order to identify the optimal approach for future environmental studies in Laos. Molecular detection by quantitative real-time PCR (qPCR) was attempted after DNA extraction directly from soil or water samples or after an overnight enrichment step. The positivity rates obtained by qPCR were compared to those obtained by different culture techniques. The rate of detection from soil samples by qPCR following culture enrichment was significantly higher (84/100) than that by individual culture methods and all culture methods combined (44/100;P< 0.001). Similarly, qPCR following enrichment was the most sensitive method for filtered river water compared with the sensitivity of the individual methods and all individual methods combined. In conclusion, molecular detection following an enrichment step has proven to be a sensitive and reliable approach forB. pseudomalleidetection in Lao environmental samples and is recommended as the preferred method for future surveys.

scholarly journals Emerging Diabetic Foot Ulcer Microbiome Analysis using Cutting Edge Technologies

2021 ◽  
pp. 193229682199009
Author(s):  
Brian M. Schmidt
Keyword(s):  
Diabetic Foot ◽  
Foot Ulcer ◽  
Diabetic Foot Ulcer ◽  
Standard Of Care ◽  
Molecular Techniques ◽  
Foot Ulcers ◽  
Care Practice ◽  
Antibiotic Administration ◽  
Diabetic Foot Ulcers ◽  
Conventional Culture

One of the most prevalent complications of diabetes mellitus are diabetic foot ulcers (DFU). Diabetic foot ulcers represent a complex condition placing individuals at-risk for major lower extremity amputations and are an independent predictor of patient mortality. DFU heal poorly when standard of care therapy is applied. In fact, wound healing occurs only approximately 30% within 12 weeks and only 45% regardless of time when standard of care is utilized. Similarly, diabetic foot infections occur in half of all DFU and conventional microbiologic cultures can take several days to process before a result is known. DFU represent a significant challenge in this regard because DFU often demonstrate polymicrobial growth, become resistant to preferred antibiotic therapy, and do not inform providers about long-term prognosis. In addition, conventional culture yields may be affected by the timing of antibiotic administration and collection of tissue for analysis. This may lead to suboptimal antibiotic administration or debilitating amputations. The microbiome of DFU is a new frontier to better understand the interactions between host organisms and pathogenic ones. Newer molecular techniques are readily available to assist in analyzing the constituency of the microbiome of DFU. These emerging techniques have already been used to study the microbiome of DFU and have clinical implications that may alter standard of care practice in the near future. Here emerging molecular techniques that can provide clinicians with rapid DFU-related-information and help prognosticate outcomes in this vulnerable patient population are presented.

Comparison of a Real-Time PCR Method with a Culture Method for the Detection of Salmonella enterica Serotype Enteritidis in Naturally Contaminated Environmental Samples from Integrated Poultry Houses

2012 ◽  
Vol 75 (4) ◽  
pp. 743-747 ◽  
Author(s):  
BWALYA LUNGU ◽  
W. DOUGLAS WALTMAN ◽  
ROY D. BERGHAUS ◽  
CHARLES L. HOFACRE
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Salmonella Enteritidis ◽  
Culture Method ◽  
Pcr Assay ◽  
Culture Methods ◽  
The Real ◽  
Selective Enrichment ◽  
Conventional Culture ◽  
Field Samples

Conventional culture methods have traditionally been considered the “gold standard” for the isolation and identification of foodborne bacterial pathogens. However, culture methods are labor-intensive and time-consuming. A Salmonella enterica serotype Enteritidis–specific real-time PCR assay that recently received interim approval by the National Poultry Improvement Plan for the detection of Salmonella Enteritidis was evaluated against a culture method that had also received interim National Poultry Improvement Plan approval for the analysis of environmental samples from integrated poultry houses. The method was validated with 422 field samples collected by either the boot sock or drag swab method. The samples were cultured by selective enrichment in tetrathionate broth followed by transfer onto a modified semisolid Rappaport-Vassiliadis medium and then plating onto brilliant green with novobiocin and xylose lysine brilliant Tergitol 4 plates. One-milliliter aliquots of the selective enrichment broths from each sample were collected for DNA extraction by the commercial PrepSEQ nucleic acid extraction assay and analysis by the Salmonella Enteritidis–specific real-time PCR assay. The real-time PCR assay detected no significant differences between the boot sock and drag swab samples. In contrast, the culture method detected a significantly higher number of positive samples from boot socks. The diagnostic sensitivity of the real-time PCR assay for the field samples was significantly higher than that of the culture method. The kappa value obtained was 0.46, indicating moderate agreement between the real-time PCR assay and the culture method. In addition, the real-time PCR method had a turnaround time of 2 days compared with 4 to 8 days for the culture method. The higher sensitivity as well as the reduction in time and labor makes this real-time PCR assay an excellent alternative to conventional culture methods for diagnostic purposes, surveillance, and research studies to improve food safety.

scholarly journals Key Role of Capsular Polysaccharide in the Induction of Systemic Infection and Abortion by Hypervirulent Campylobacter jejuni

2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Orhan Sahin ◽  
Samantha A. Terhorst ◽  
Eric R. Burrough ◽  
Zhangqi Shen ◽  
Zuowei Wu ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Campylobacter Jejuni ◽  
Capsular Polysaccharide ◽  
Systemic Infection ◽  
The United States ◽  
Content Type ◽  
Model Following ◽  
Capsule Production ◽  
Guinea Pig Model

ABSTRACT Campylobacter jejuni is a zoonotic pathogen, and a hypervirulent clone, named clone SA, has recently emerged as the predominant cause of ovine abortion in the United States. To induce abortion, orally ingested Campylobacter must translocate across the intestinal epithelium, spread systemically in the circulation, and reach the fetoplacental tissue. Bacterial factors involved in these steps are not well understood. C. jejuni is known to produce capsular polysaccharide (CPS), but the specific role that CPS plays in systemic infection and particularly abortion in animals remains to be determined. In this study, we evaluated the role of CPS in bacteremia using a mouse model and in abortion using a pregnant guinea pig model following oral challenge. Compared with C. jejuni NCTC 11168 and 81-176, a clone SA isolate (IA3902) resulted in significantly higher bacterial counts and a significantly longer duration of bacteremia in mice. The loss of capsule production via gene-specific mutagenesis in IA3902 led to the complete abolishment of bacteremia in mice and abortion in pregnant guinea pigs, while complementation of capsule expression almost fully restored these phenotypes. The capsule mutant strain was also impaired for survival in guinea pig sera and sheep blood. Sequence-based analyses revealed that clone SA possesses a unique CPS locus with a mosaic structure, which has been stably maintained in all clone SA isolates derived from various hosts and times. These findings establish CPS as a key virulence factor for the induction of systemic infection and abortion in pregnant animals and provide a viable candidate for the development of vaccines against hypervirulent C. jejuni.

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