Culture Methods For Detection Research Articles

Francisella noatunensis subsp. orientalis infection in Indo‐Pacific reef fish entering the United States through the ornamental fish trade

Journal of Fish DiseasesVolume 36, Issue 7 p. 681-684 Short Communication Francisella noatunensis subsp. orientalis infection in Indo-Pacific reef fish entering the United States through the ornamental fish trade A C Camus, A C Camus Department of Pathology, College of Veterinary Medicine, University of Georgia Athens, Athens, GA, USASearch for more papers by this authorJ A Dill, J A Dill Department of Pathology, College of Veterinary Medicine, University of Georgia Athens, Athens, GA, USASearch for more papers by this authorA J McDermott, A J McDermott Department of Veterinary Services, Georgia Aquarium, Atlanta, GA, USASearch for more papers by this authorT M Clauss, T M Clauss Department of Veterinary Services, Georgia Aquarium, Atlanta, GA, USASearch for more papers by this authorA L Berliner, A L Berliner Memphis Zoo, Memphis, TN, USASearch for more papers by this authorS M Boylan, S M Boylan South Carolina Aquarium, Charleston, SC, USASearch for more papers by this authorE Soto, Corresponding Author E Soto Department of Pathobiology, School of Veterinary Medicine, Ross University, Basseterre, St. Kitts, West Indies Correspondence E Soto, Ross University, School of Veterinary Medicine, Department of Pathobiology, P.O. Box 334, Basseterre, St. Kitts, West Indies (e-mail: esoto@rossvet.edu.kn)Search for more papers by this author A C Camus, A C Camus Department of Pathology, College of Veterinary Medicine, University of Georgia Athens, Athens, GA, USASearch for more papers by this authorJ A Dill, J A Dill Department of Pathology, College of Veterinary Medicine, University of Georgia Athens, Athens, GA, USASearch for more papers by this authorA J McDermott, A J McDermott Department of Veterinary Services, Georgia Aquarium, Atlanta, GA, USASearch for more papers by this authorT M Clauss, T M Clauss Department of Veterinary Services, Georgia Aquarium, Atlanta, GA, USASearch for more papers by this authorA L Berliner, A L Berliner Memphis Zoo, Memphis, TN, USASearch for more papers by this authorS M Boylan, S M Boylan South Carolina Aquarium, Charleston, SC, USASearch for more papers by this authorE Soto, Corresponding Author E Soto Department of Pathobiology, School of Veterinary Medicine, Ross University, Basseterre, St. Kitts, West Indies Correspondence E Soto, Ross University, School of Veterinary Medicine, Department of Pathobiology, P.O. Box 334, Basseterre, St. Kitts, West Indies (e-mail: esoto@rossvet.edu.kn)Search for more papers by this author First published: 11 January 2013 https://doi.org/10.1111/jfd.12071Citations: 20Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume36, Issue7July 2013Pages 681-684 RelatedInformation

Diagnostic value of latex agglutination test in diagnosis of acute bacterial meningitis

Objectives:To know the incidence of bacterial meningitis in children below five years of age. To compare conventional culture and antigen detection methods (Latex agglutination test).Materials and Methods:100 CSF samples of clinically suspected meningitis cases in children below 5 years of age were included. The samples were subjected to cell count, Gram stain, culture and LAT. The organisms isolated in the study were characterized according to standard procedures.Results:Of the 100 cases studied, 31 cases were diagnosed as ABM by Gram stain, culture and latex agglutination test as per WHO criteria. The hospital frequency of ABM was 1.7%. 15 (48.38) cases were culture positive. Gram stain was positive in 22(70.96) cases and LAT in 17(54.83) cases. Haemophilus influenzae was the most common causative agent of acute bacterial meningitis followed by S.pneumoniae. Case fatality rate was 45.16%. The sensitivity and specificity of LAT was 66.66% and 87.91% respectively.Conclusion:Bacterial meningitis is a medical emergency and early diagnosis and treatment is life saving and reduces chronic morbidity. LAT was more sensitive compared to conventional Gram stain and Culture technique in identifying the fastidious organisms like H.influenzae, S.pneumoniae and Group B Streptococcus. However, the combination of Gram stain, Culture and LAT proved to be more productive than any of the single tests alone.

Effectiveness and clinical applications of real-time fluorescence-based quantitative PCR system for the detection of Clostridium perfringens

2cfu/ml pure C. perfringens, or 9 cfu/reaction. The procedure was stable, repeatable and fast, taking only 3 h in total. Detection results of 500 wound secretions using this PCR method were consistent with those obtained using conventional culture detection methods, demonstrating for the first time that this fluorescence-based quantitative PCR system is effective, accurate and applicable on a large sample scale under clinical conditions. We have thus provided a highly specific, sensitive, fast, and accurate fluorescence-based quantitative PCR technique that can quickly diagnose the early stages of gas gangrene. This may be especially valuable in batch testing, such as in the event an earthquake or other emergency.

A review of the current status of cultural and rapid detection of Vibrio parahaemolyticus

SummaryVibrio parahaemolyticus is ubiquitous in estuarine environments and can be commonly found in seafood products. This bacterial pathogen continues to emerge as an important cause of foodborne illness, and several foodborne disease outbreaks caused by V. parahaemolyticus have been linked to the consumption of contaminated seafood, in particular those consumed raw such as oysters. In response to these outbreaks, especially during the 1990s, several cultural, immunological‐based and molecular detection methods have been developed, which allow for rapid detection and quantification of total and pathogenic V. parahaemolyticus. The development of molecular methodology has allowed for clinical and environmental isolates of V. parahaemolyticus to be subtyped, thus providing the framework for risk‐based strategies aimed at controlling foodborne outbreaks cause by this pathogen. It is important that the detection and typing methods strive to accomplish detection and differentiation of the pathogenic strains from environmental (non‐pathogenic) ones, as well as to detect the presence of the organism and not just the presence of V. parahaemolyticus produced toxins, which can also be produced by closely related species. This review covers the current status of detection and typing methodology for identification and characterisation of V. parahaemolyticus from seafood.

Development and validation of real‐time PCR for the detection of Yersinia ruckeri

Yersiniosis (enteric red mouth disease) is a contagious bacterial disease caused by Yersinia ruckeri, which primarily affects salmonids. A real-time PCR assay using a molecular beacon has been developed and validated to improve the detection of the causative biotypes of Y. ruckeri. The assay, which targets the glnA (glutamine synthetase) gene, proved to have 100% analytical specificity and analytical sensitivities of 5 fg and 3 × 10(3) CFU g(-1) for DNA and seeded kidney tissue, respectively. The assay was highly repeatable with low % CV for intra- and inter-run experiments, and the optimized parameters transferred easily between different real-time PCR platforms. Following analytical validation, diagnostic specificity was determined using New Zealand farmed Chinook salmon (n = 750) from 10 farms during 2007/08. The real-time PCR was run in parallel with the bacterial culture detection method, and all fish tested were found to be negative by both methods for Y. ruckeri, resulting in 100% diagnostic specificity (95% confidence interval). The molecular beacon real-time PCR system is specific, sensitive, reproducible and a rapid method for the detection of Y. ruckeri and has the potential to be used for routine diagnostic testing, health certification and active surveillance programmes.

Real-Time Qualitative PCR for 57 Human Adenovirus Types from Multiple Specimen Sources

Human adenoviruses (HAdVs) are ubiquitous double-stranded DNA viruses that cause a wide array of diseases in humans including pharyngitis, pneumonia, gastroenteritis, hemorrhagic cystitis, and keratoconjunctivitis. They also cause life-threatening opportunistic infections in immunocompromised individuals and are responsible for outbreaks in certain populations. Diagnosis is traditionally by cell culture or antigen detection methods. However, some HAdVs can take up to 4 weeks to isolate, and diarrheagenic types 40 and 41 will not grow in routine cell culture. Therefore, the goal of this study was to design a rapid, real-time PCR assay to detect all known 57 HAdV types from multiple different specimen sources. Primers and fluorescence resonance energy transfer hybridization probes were designed to target a 185-bp region of the penton base gene of HAdV. The analytical sensitivity was determined to be 10 copies/μl for HAdV types showing exact primer/probe homology in specimen matrix. Using whole-virus strains, the analytical sensitivity for representative HAdV types ranged from 10(-1) to 10(3) 50% tissue culture infective dose (TCID(50))/ml. The assay demonstrated 100% sensitivity and 99% specificity. This real-time PCR assay provides a rapid method for the detection of all 57 known HAdV types from respiratory specimens, blood, stool, urine, and ocular swabs.

Reveal® Salmonella 2.0 Test for Detection of Salmonella spp. in Foods and Environmental Samples

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A-E in a variety of food and environmental samples. A Performance Tested Method validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A-E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time.

Reveal®Salmonella 2.0 Test for Detection of Salmonella spp. in Foods and Environmental Samples

Abstract Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A–E in a variety of food and environmental samples. A Performance Tested MethodSM validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A–E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time.

Comparison of Two Multiplex Methods for Detection of Respiratory Viruses: FilmArray RP and xTAG RVP

We compared the FilmArray RP (Idaho Technology, Inc., Salt Lake City, UT) and the xTAG RVP (Luminex Corporation, Toronto, Canada) multiplex respiratory virus PCR methods for the detection of respiratory viruses in a set of 200 patient specimens frozen at -70 °C after standard viral culture and antigen detection methods were done. Both systems detected between 40 to 50% more viruses than traditional methods, primarily rhinoviruses and human metapneumovirus. The FilmArray RP detected significantly more total viruses either alone or as part of mixed infections than the xTAG RVP, as well as an additional 21.6% more respiratory syncytial viruses. The xTAG RVP requires 5 to 6 h with 2.5 to 3 h of hands-on time, while the FilmArray RP takes about an hour with 3 to 5 min of hands-on time, making it much easier to perform.

Use of culture and molecular analysis to determine the effect of antibiotic treatment on microbial community diversity and abundance during exacerbation in patients with cystic fibrosis

BackgroundAnaerobic bacteria are increasingly regarded as important in cystic fibrosis (CF) pulmonary infection. The aim of this study was to determine the effect of antibiotic treatment on aerobic and anaerobic...

Prevalence of Salmonella in pig ear pet treats

Salmonella is one of the most important causes of foodborne disease throughout the world. In recent years there have been documented outbreaks of Salmonella infection in humans associated with pet treats of animal origin; in particular pig ear pet treats in Canada and the United States. The main objectives of this study were to determine the degree of Salmonella contamination in dried pig ear dog treats on sale in Limerick City, Ireland and to examine pet dogs for Salmonella carriage. Over a 12month period, from October 2008 to September 2009, 102 pig ear pet treats were sampled using both a conventional culture detection method and a PCR method. Salmonella was detected in 24.5% of samples by the culture method, while 28.4% tested positive using a PCR method. Resistance to at least one antimicrobial agent was observed in 50% of Salmonella isolates. Salmonella was not detected in any of 86 rectal swabs from dogs attending 2 different veterinary clinics between February and April and August and October of that period. The contaminated ears were traced back to a single distributor. This study emphasises that there is a long term continuing risk of human exposure to Salmonella associated with pig ear treats.

P113 Diagnostic algorithm using a sensitive broth culture method for detection of Clostridium difficile toxin from stool samples

P113 Diagnostic algorithm using a sensitive broth culture method for detection of Clostridium difficile toxin from stool samples

Evaluation of a new one-step enrichment in conjunction with a chromogenic medium for the detection of Cronobacter spp. (Enterobacter sakazakii) in powdered infant formula.

The aim of the present study was to evaluate a new one-step enrichment protocol, consisting of a combined preenrichment and enrichment broth (Cronobacter Enrichment Broth [CEB]) used in conjunction with selective-differential agar ChromID Sakazakii, to facilitate a shortened 2-day cultural method for detection of Cronobacter spp. (Enterobacter sakazakii) in powdered infant formula (PIF). The CEB was evaluated using samples artificially inoculated with low concentrations of 10 lyophilized strains, representative of the genus Cronobacter. The detection of strains was compared in parallel with the enrichment medium from ISO/TS 22964 and a recently proposed differential screening broth for the detection of Cronobacter. All of the Cronobacter strains were recovered using the CEB, and a significantly higher final bacterial concentration was obtained with the CEB than with the other enrichment broths (P < 0.01). There was no significant difference between the cell concentrations for cultures grown in CEB at 37 degrees C and those grown at 41.5 degrees C. Cronobacter was recovered from both 1/10 (50 g:450 ml) and 1/5.5 (100 g:450 ml) sample-to-broth ratios, with no significant difference observed between the final bacterial concentrations obtained from the two ratios. Further studies on a wider range of PIFs, including naturally contaminated samples, are warranted to determine if the use of this protocol may facilitate the rapid release (within 40 to 48 h) of PIF.

Application of magnetic immuno-polymerase chain reaction assay for detection of Salmonella spp. in chicken meats

Since contaminated chicken meats have been the principal foodborne source of the contamination of Salmonella to human beings and cultural detection methods are labor-intensive and time-consuming, a study evaluating the performance of the combination of two techniques that are immunomagnetic separation (IMS) and polymerase chain reaction (PCR) for the detection of Salmonella in chicken meats was conducted. The IMS and PCR assay combines selective extraction of Salmonella by specific antibodies with primer-specific (primer pair based on the sequence of invA gene) PCR amplification. Initially chicken meat samples, in which no Salmonella contamination had been determined by using ISO 6579 reference method, were inoculated with Salmonella Enteritidis culture and subsequently the shortest non-selective pre-enrichment time, that had been needed for the detection of approximately 1 or 10 CFU/mL chicken meat levels of target bacteria by magnetic immuno-PCR assay, was found by using 14, 12, 10 and 8-h periods. In conclusion, it was found that magnetic immuno-PCR assay was able to detect 1–10 CFU Salmonella/25 g chicken meat, after only incorporating a non-selective pre-enrichment period of 12 h. Therefore, an overall 16-h (magnetic immuno-PCR assay in conjunction with 12-h non-selective pre-enrichment) magnetic immuno-PCR assay statistically evaluated as sufficient (p = 0.182 > 0.05) for rapid and sensitive detection of approximately 1–10 CFU Salmonella from 25 g chicken meat samples. Accordingly, 16-h magnetic immuno-PCR assay can be promising for routine use in the detection of Salmonella in chicken meat samples, and it consequently may prevent the risk of Salmonella infections in regard to chicken meats.

Cell‐culture‐based immunochromatography for rapid detection of group A human rotaviruses in aquatic environments

In an effort to detect rapidly and conveniently the infectious waterborne group A human rotaviruses that cause diarrhea in infants and children, the authors developed the first‐ever cell‐culture‐based immunochromatography method. An immunochromatography kit interacted only with the human rotaviruses VP6 antigen, and the cell‐culture‐based immunochromatography detected group A human rotaviruses with a sensitivity as low as 1.99 TCID50 ml−1. This detection sensitivity was similar to that of the cytopathic effect‐based method. There were no actual differences between the sensitivity of this method and that of the real‐time reverse transcription polymerase chain reaction method, which is known as a method with a relatively high sensitivity. Furthermore, while cell culture detection methods, that is total culturable virus assay, can determine only the presence of infectious waterborne viruses, the cell‐culture‐based immunochromatography is advantageous for the accurate detection of group A human rotaviruses. Compared with the real‐time reverse transcription polymerase chain reaction method, the cell‐culture‐based immunochromatography is advantageous because it requires a relatively simple process that enables easy quality controls and low test costs. Thus, this study proposed a new method for the identification of group A human rotaviruses, and it is suggested that this cell‐culture‐based immunochromatography may be applied to detect group A human rotaviruses in aquatic environments.

Real-Time PCR with an Internal Control for Detection of All Known Human Adenovirus Serotypes

The "gold standard" for the diagnosis of adenovirus (AV) infection is virus culture, which is rather time-consuming. Especially for immunocompromised patients, in whom severe infections with AV have been described, rapid diagnosis is important. Therefore, an internally controlled AV real-time PCR assay detecting all known human AV serotypes was developed. Primers were chosen from the hexon region, which is the most conserved region, and in order to cover all known serotypes, degenerate primers were used. The internal control (IC) DNA contained the same primer binding sites as the AV DNA control but had a shuffled probe region compared to the conserved 24-nucleotide consensus AV hexon probe region (the target). The IC DNA was added to the clinical sample in order to monitor extraction and PCR efficiency. The sensitivity and the linearity of the AV PCR were determined. For testing the specificity of this PCR assay for human AVs, a selection of 51 AV prototype strains and 66 patient samples positive for other DNA viruses were tested. Moreover, a comparison of the AV PCR method described herein with culture and antigen (Ag) detection was performed with a selection of 151 clinical samples. All 51 AV serotypes were detected in the selection of AV prototype strains. Concordant results from culture or Ag detection and PCR were found for 139 (92.1%) of 151 samples. In 12 cases (7.9%), PCR was positive while the culture was negative. In conclusion, a sensitive, internally controlled nonnested AV real-time PCR assay which is able to detect all known AV serotypes with higher sensitivity than a culture or Ag detection method was developed.

Direct nucleic acid-based detection of MRSA from clinical specimens1

Over the past few years a dramatic increase in the methicillin resistance of S. aureus isolates has been observed worldwide. Infections with methicillin-resistant Staphylococcus aureus (MRSA) are accompanied by higher rates of morbidity and mortality, extended length of stay and increased overall costs. Large-scale hygienic measures are necessary to prevent the spread of the resistant isolates to patients not yet infected or colonized by MRSA. It has been demonstrated that the sooner such measures are taken, the smaller the probability of transmission to other patients. To achieve this result requires rapid identification of MRSA carriers. Even more recent culture-based detection methods can provide results only after 24 h. The use of modern PCR-supported detection methods opens the possibility to record findings within only a few hours. While the original test concepts, which are based on the separate detection of the mecA gene and various markers for S. aureus, have proven to be a good culture verification test, they are of limited usefulness for the rapid and meaningful direct detection of MRSA in clinical specimens. Recently developed, innovative test concepts based on the targeted detection of the integration of a so-called SCCmec element (a gene cluster typically also harboring the methicillin-resistance transmitting mecA-gen) in the S. aureus genome are better suited for this purpose. At present there exist a number of commercial test systems as well as a multitude of test concepts developed in-house, all of which are based on this fundamental principle. Although these assays usually display high levels of sensitivity (90–100%), specificity (93–99%) and positive predictive values above 95%, their negative predictive values are usually distinctly lower (80–95%). Meanwhile, with the increasingly broader use of these test methods several disturbance variables have been identified that can lead to false positive or false negative results. In view of these limits a combination of PCR-supported and cultural detection methods would appear to present a sensible policy.

Invasive infections caused by Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae among children in St Petersburg, Russia

This study investigated the causes of invasive bacterial infections in children aged <15 years in St Petersburg, Russia, during 2001-2003, using culture and antigen detection methods (rapid antigen latex agglutination (RAL)) for normally sterile body fluids. A pathogen was detected in 90 cases (culture 50, RAL 40). Neisseria meningitidis was the most common pathogen (66%), followed by Haemophilus influenzae (19%) and Streptococcus pneumoniae (16%). Meningitis was the main clinical diagnosis (68/90, 76%), with N. meningitidis serogroup B, H. influenzae type b (Hib), and S. pneumoniae serogroup 1 being the most common isolates. Hib was less prevalent in St Petersburg than it was in industrialised countries before the introduction of Hib vaccinations.

Application of duplex-PCR in rapid and reliable detection of toxigenic Vibrio cholerae in water samples in Thailand

Toxigenic Vibrio cholerae, the cause of cholera, is a native flora of the aquatic environment which is transmitted through drinking water and still remains the leading cause of morbidity and mortality in many developing countries including Thailand. The culture method (CM), which is routinely used for assessing water quality, has not proven as efficient as molecular methods because the notorious pathogen survives in water mostly in a non-culturable state. We employed duplex-polymerase chain reaction (duplex-PCR) for detection of tcpA and ctxA genes in toxigenic V. cholerae, and compared PCR detection with CM in various waters of Khon Kaen Municipality, Thailand. We also evaluated the effect of different pre-PCR conditions on the results of ctxA and tcpA detection including: 1) water filtered and enriched in alkaline peptone water (APW) for 3 h before PCR, 2) water filtered without enrichment before PCR, and 3) use of only enrichment in APW for 6 h before PCR. Of the 96 water samples (taken from waste-water, potable and waste-water from patients' houses, and from rivers) tested, 48 (50%) were positive for ctxA and tcpA by duplex-PCR, whereas only 29 (30%) were positive for V. cholerae by CM. Of the 29 V. cholerae isolated by CM, 2 (7%) were toxigenic V. cholerae belonging to serovar O1, while the rests were non-O1/ non-O139. Results revealed, therefore, that ctxA and tcpA-targeted duplex PCR is more sensitive than CM for detection of toxigenic V. cholerae from water samples because CM detected much less toxigenic V. cholerae than the non-toxigenic V. cholerae. Template DNA as low as 100 fg or 23 cells of V. cholerae in the water sample was detected in duplex PCR. Pre-PCR filtration followed by enrichment for 3 h significantly increase in the efficiency of duplex-PCR detection of toxigenic V. cholerae.

Cultural and Immunological Detection Methods for Salmonella spp. in Animal Feeds – A Review

Food-borne salmonellosis continues to be a major public health concern, and contamination with Salmonella spp. in pre-harvest animal production is considered a primary contributor to this problem. Animal feeds can easily become contaminated during primary production, feed mixing and processing as well as during feeding. Consequently, monitoring and surveillance of feeds and feed ingredients for Salmonella spp. contamination may be useful or necessary in the prevention and control of this organism. Cultural and immunological detection methods for salmonellae have been used or suggested as possible approaches for use in animal feeds. Cultural methods remain advantageous owing to their ability to detect viable bacterial cells, while immunological methods have the capability of detecting nonculturable bacterial cells. Advancements and improvements in both methodologies offer opportunities for eventual routine use of these detection technologies in animal feed assays.