Nested Polymerase Chain Reaction Approach Research Articles

Prevalence and risk factors of oral human papillomavirus infection among 4212 healthy adults in Hebei, China

BackgroundHuman papillomavirus (HPV) infection is an essential cause of oropharyngeal squamous cell carcinoma that is increasing in incidence worldwide. However, little is known about the epidemiology of oral HPV infection among healthy adults in China.MethodsA study in northern China was conducted in 2021 as baseline data of Diverse Life-Course Cohort (DLCC). Residents who aged above 20 were eligible to participate. Oral swab specimens and questionnaires were collected from 4226 participants. HPV DNA in oral exfoliated cells was tested by Nested Polymerase Chain Reaction approach and sequencing. Univariate and multivariate analyses were performed to assess the associations between exposure factors and oral HPV infection.ResultsOverall prevalence of oral HPV infection was 4.08% (95%CI, 3.69%-4.68%). The most prevalent HPV type detected was HPV-81 (1.35%; 95% CI, 1.00%–1.70%), followed by HPV-16 (0.64%; 95% CI, 0.40%–0.88%). Oral HPV infection presented a bimodal pattern with respect to age in male and female participants. Oral HPV prevalence of male participants was significantly higher than prevalence of female participants (5.0% versus 3.6%, P = 0.041). Prevalence of oral HPV was higher among current smokers (OR = 1.59; 95% CI, 1.11–2.29; P = 0.039) and current drinkers (OR = 1.60; 95% CI, 1.14–2.25; P = 0.023). Current alcohol consumption was independently associated with oral HPV infection (OR = 1.74; 95% CI, 1.22–2.50; P = 0.010).ConclusionsAmong healthy adults aged above 20 in Hebei, China, the prevalence of high-risk HPV infection was 1.92% (95%CI, 1.51%-2.34%). Oral HPV prevalence was independently associated with alcohol consumption. More tailored prevention strategies are needed to prevent oral HPV infection through smoking cessation, reduction of alcohol consumption, and HPV vaccination.

Molecular characterization of hepatitis B virus basal core promoter and precore region of isolates from chronic hepatitis B patients.

To analyse mutations in precore and core promoter regions of hepatitis B virus genome in chronic hepatitis B patients. The cross-sectional prospective study was conducted at the Centre of Biotechnology and Microbiology, University of Peshawar and Pakistan Health Research Council (PHRC), Research Centre, Khyber Medical College Peshawar from June 2014 to June 2015, and comprised samples from treatment-naïve chronic hepatitis B patients aged >15 years from three cities of Pakistan. The samples included patients who were both positive and negative for hepatitis B envelope antigen. Viral load, hepatitis B envelope antigen / anti-hepatitis B envelope status, hepatitis B virus enzyme-linked immunosorbent assay and alanine aminotransferase levels were determined. Direct sequencing of basal core promoter and precore regions of hepatitis B virus genome was carried out following a nested polymerase chain reaction approach. Phylogenetic tree was constructed using Molecular Evolutionary Genetics Analysis software version 6.0. Data was analysed using SPSS 16. Of the 50 patients, 33(66%) were males. The overall mean age was 28.5±11.4 years. Of all the subjects, 25(50%) each were positive and negative for hepatitis B envelope antigen. Precore stop codon mutation G1896A was detected in 19 (38%) isolates; 17(34%) among negative patients and 2(4%) in positive patients. Classic A1762T/G1764A double mutation was noted in 15(30%) isolates. Mutation at position 1764 was observed in 12(48%) samples. A rare G1764T mutation was also detected in 6(12%) isolates. The CG1802-1803 mutation was detected in 47(94%) isolates, while all the 50(100%) isolates had T1858A. The GCAC Kozak sequence was present in 43(86%) isolates; CAA1817-1819 in 49(98%); and G1888 in 49(98%). Overall, 9(18%) isolates had wild-type sequences at all important loci, including positions 1762, 1764 and 1896. The pattern of sequences at genotype specific positions and phylogenetic tree speculates that majority of study isolates belonged to genotype D. Basal core promoter and precore regions variants along with the preponderances of genotype D-specific mutations suggested a higher risk of hepatocellular carcinoma and poor clinical outcome in such patients.

Genetic Diversity of Babesia bovis MSA-1, MSA-2b and MSA-2c in China.

The apicomplexan parasite Babesia bovis is a tick-borne intracellular hemoprotozoan parasite that is widespread across China. Genetic diversity is an important strategy used by parasites to escape the immune responses of their hosts. In our present study, 575 blood samples, collected from cattle in 10 provinces, were initially screened using a nested PCR (polymerase chain reaction) for detection of B. bovis infection. To perform genetic diversity analyses, positive samples were further amplified to obtain sequences of three B. bovis merozoite surface antigen genes (MSA-1, MSA-2b, MSA-2c). The results of the nested PCR approach showed that an average of 8.9% (51/575) of cattle were positive for B. bovis infection. Phylogenetic analyses of the predicted amino acid sequences revealed that unique antigen variants were formed only by Chinese isolates. Our findings provide vital information for understanding the genetic diversity of B. bovis in China.

Low prevalence of human papillomavirus infection in sinonasal inverted papilloma and oncocytic papilloma.

The aim of this study was to investigate the role of human papillomavirus (HPV) in sinonasal inverted papilloma (SIP) and sinonasal oncocytic papilloma (SOP) from a single institution and whether p16 can serve as a surrogate marker for HPV infection. This study included 49 subjects with SIP and 36 subjects with SOP. Formalin-fixed paraffin-embedded tissues were used to extract genomic DNA, and HPV detection was performed by utilizing a valid nested polymerase chain reaction approach that can detect all known HPV subtypes. Immunohistochemistry was used to evaluate the expression of p16 in all tumor sections. The presence of HPV DNA was found in 6.1% (3/49) of the SIP patients and 11.1% (4/36) of the SOP patients. All identified HPV subtypes in SIP were high-risk HPV, including HPV-16 (two patients) and HPV-58 (one patient). Regarding SOP, there were three patients positive for HPV-16 and one with low-risk HPV (type 6). In total, 11/49 (22.4%) SIP lesions and 10/36 (27.8%) SOP lesions were considered p16 positive, with p16 staining in more than 70% of tumor cells. There was only one SIP and one SOP that were positive for both HPV (high-risk HPV type 16) and p16 staining. HPV does not play an etiologic role in inverted papilloma or oncocytic papilloma of the sinonasal region. p16 immunostaining should not be used as a surrogate marker to evaluate the HPV infection status in these lesions.

Fucosyltransferase Gene Polymorphisms and Lewisb-Negative Status Are Frequent in Swedish Newborns, With Implications for Infectious Disease Susceptibility and Personalized Medicine.

Single-nucleotide polymorphisms (SNPs) in the fucosyltransferase genes FUT2 and FUT3 have been associated with susceptibility to various infectious and inflammatory disorders. FUT variations influence the expression of human histo-blood group antigens (HBGAs) (H-type 1 and Lewis), which are highly expressed in the gut and play an important role in microbial attachment, metabolism, colonization, and shaping of the microbiome. In particular, FUT polymorphisms confer susceptibility to specific rotavirus and norovirus genotypes, which has important global health implications. We designed a genotyping method using a nested polymerase chain reaction approach to determine the frequency of SNPs in FUT2 and FUT3, thereby inferring the prevalence of Lewisb-positive, Lewisb-negative, secretor, and nonsecretor phenotypes in 520 Swedish newborns. There was an increased frequency of homozygotes for the minor allele for 1 SNP in FUT2 and 4 SNPs in FUT3. Overall, 37.3% of newborns were found to have Lewis b negative phenotypes (Le (a+b-) or Le (a-b-). Using our new, sensitive genotyping method, we were able to genetically define the Le (a-b-) individuals based on their secretor status and found that the frequency of Lewis b negative newborns in our cohort was 28%. Given the high frequency of fucosyltransferase polymorphisms observed in our newborn cohort and the implications for disease susceptibility, FUT genotyping might play a future role in personalized health care, including recommendations for disease screening, therapy, and vaccination.

Encephalitozoon cuniculi in Raw Cow's Milk Remains Infectious After Pasteurization.

This study describes the prevalence of Encephalitozoon cuniculi in raw cow's milk and evaluates the effect of different milk pasteurization treatments on E. cuniculi infectivity for severe combined immunodeficient (SCID) mice. Using a nested polymerase chain reaction approach, 1 of 50 milking cows was found to repeatedly shed E. cuniculi in its feces and milk. Under experimental conditions, E. cuniculi spores in milk remained infective for SCID mice following pasteurization treatments at 72 °C for 15 s or 85 °C for 5 s. Based on these findings, pasteurized cow's milk should be considered a potential source of E. cuniculi infection in humans.

Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections.

BackgroundMolecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques.MethodsA nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1–4), rhinovirus, adenovirus (A—F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011–2013. The results were corroborated in an independent cohort collected in the UK.ResultsA total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12–24 months age group. The most frequently observed co-infection patterns were RSV—Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV—bocavirus / bocavirus—influenza (5 patients, 5.2%, UK cohort).ConclusionThe presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12–24 months of age. The clinical significance of these findings is unclear but should warrant further analysis.

Detection of fetal mutations causing hemoglobinopathies by non-invasive prenatal diagnosis from maternal plasma

Prenatal diagnosis of hemoglobinopathies enables couples at risk to have a healthy child. Currently used fetal sampling procedures are invasive with some risk of miscarriage. A non-invasive approach to obtain fetal deoxyribonucleic acid (DNA) for diagnosis would eliminate this risk. To develop and evaluate a non-invasive prenatal diagnostic approach for hemoglobinopathies using cell-free fetal DNA circulating in the maternal plasma. Couples referred to us for prenatal diagnosis of hemoglobinopathies where the maternal and paternal mutations were different were included in the study. Maternal peripheral blood was collected at different periods of gestation before the invasive fetal sampling procedure was done. The blood was centrifuged to isolate the plasma and prepare DNA. A size separation approach was used to isolate fetal DNA. Nested polymerase chain reaction (PCR)-based protocols were developed for detection of the presence or absence of the paternal mutation. There were 30 couples where the parental mutations were different. Of these, in 14 cases the paternal mutation was absent and in 16 cases it was present in the fetus. Using cell-free fetal DNA from maternal plasma, the absence of the paternal mutation was accurately determined in 12 of the 14 cases and the presence of the paternal mutation was correctly identified in 12 of the 16 cases. Thus, this non-invasive approach gave comparable results to those obtained by the conventional invasive fetal sampling methods in 24 cases giving an accuracy of 80.0%. Although the nested PCR approach enabled amplification of small quantities of cell-free DNA from maternal plasma at different periods of gestation after size separation to eliminate the more abundant maternal DNA, an accurate diagnosis of the presence or absence of the paternal mutation in the fetus was not possible in all cases to make it clinically applicable.

ATTR amyloid in the carpal tunnel ligament is frequently of wildtype transthyretin origin

The carpal tunnel ligament often encloses transthyretin-derived (ATTR) amyloid deposits. In this study we tested the hypothesis that ATTR amyloid in the carpal tunnel ligament is most commonly of wildtype origin in a Caucasian population without endemic background of familial amyloid polyneuropathy. All resection specimens from the carpal tunnel ligament were retrieved from the Amyloid Registry of the University of Kiel spanning the period of 2004–2011 and dichotomized into two study groups: the first study group of 25 patients was obtained from diverse referring pathologists. The second group comprised a patient cohort of 73 patients obtained from a single-referring department of pathology. The selection of biopsies was based on the histological identification of amyloid by Congo red staining and polarization microscopy between crossed polars and immunohistochemical classification as ATTR amyloid. A novel anti-TTR-peptide antibody was raised in rabbits using a recombinant peptide (FHEHAEVVFTANDSGPRRYT) spanning residues 87–106 of the TTR protein. Amplification of the TTR exons 1, 2, 3 and 4 was done by a nested polymerase chain reaction approach. Ninety-eight biopsies were available from 98 patients, including 51 women and 47 men. All amyloid deposits showed strong immunoreactions with the novel anti-TTR peptide antibody. In 81 of 98 patients, genomic DNA was available. In 10 (12%) patients non-amyloidogenic TTR gene mutations were found with the following amino acid substitutions: p.G6S (normal allelic variant). A single patient carried a p.G6S and a p.M13I-variant. The remaining patients all showed wildtype sequence of the TTR gene (70 patients). No significant difference was found between the two study groups. ATTR amyloid in the carpal tunnel ligament is commonly of wildtype origin and genetic counseling is not mandatory in these patients.Abbreviations: ATTR, transthyretin derived amyloid; CTS, carpal tunnel syndrome; DNA, deoxyribnucleid acid; SSA, senile systemic amyloidosis; TTR, transthyretin

Impact of different polymerase chain reaction (PCR) strategies on denaturing gradient gel electrophoresis- based analysis of bacterial communities in soils/sediments from the Northern Jiangsu Oil Field, China

The selection of polymerase chain reaction (PCR) strategies is vital to a successful assessment of bacterial communities in soils/sediments by 16S rRNA gene-based denaturing gradient gel electrophoresis (DGGE) analysis. To obtain reliable information of the bacteria communities in soils/sediments from the Northern Jiangsu Oil Field (NJOF), the impact of six PCR strategies on DGGE analysis has been investigated. The results showed that one-step PCR approach with primer set 341f⊥GC/534r (Strategies 1 and 2) was not suitable for 16S rRNA gene amplification of the bacterial communities in the NJOF soils/sediments before DGGE analysis due to its non-specific DNA amplification and low efficiency of 16S rRNA gene amplification. Strategy 6 (one nested PCR approach with primer sets 27f/907r and 341f⊥GC/534r with a purification procedure) could be the most accurate assessment of community diversities, but only be suitable to perform DGGE analysis for a few samples and not for high-throughput DGGE analysis because it was time-consuming; and Strategies 5 (one nested PCR approach with a dilution procedure) and 3 (one two-step PCR approach with primer sets 341f /534r and 341f⊥GC/534r) could provide similar information on the bacterial diversity of the NJOF soils/sediments without a purification procedure comparing with Strategy 6. Therefore, we prefer to recommend Strategies 5 and 3 for high-throughput DGGE analysis, and have successfully obtained the useful information of bacterial communities in different NJOF soils/sediments by Strategies 5. Key words: Polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE) analysis, bacterial diversity, soils/sediments, Northern Jiangsu Oil Field (NJOF).

Identification of Naegleria fowleri in Warm Ground Water Aquifers

The free-living amoeba Naegleria fowleri was identified as the etiological agent of primary amoebic meningoencephalitis that caused the deaths of two children in Peoria, Arizona, in autumn of 2002. It was suspected that the source of N. fowleri was the domestic water supply, which originates from ground water sources. In this study, ground water from the greater Phoenix Metropolitan area was tested for the presence of N. fowleri using a nested polymerase chain reaction approach. Phylogenetic analyses of 16S rRNA sequences of bacterial populations in the ground water were performed to examine the potential link between the presence of N. fowleri and bacterial groups inhabiting water wells. The results showed the presence of N. fowleri in five out of six wells sampled and in 26.6% of all ground water samples tested. Phylogenetic analyses showed that beta- and gamma-proteobacteria were the dominant bacterial populations present in the ground water. Bacterial community analyses revealed a very diverse community structure in ground water samples testing positive for N. fowleri.

Genotyping the GGGCGG Tandem Repeat Promoter Polymorphism in the 5-Lipoxygenase Enzyme Gene (ALOX5) by Pyrosequencing Assay

Efficient genotyping methods for many biologically significant repeat genetic polymorphisms, particularly in GC-rich regions of the genome, are limited. In particular, a short tandem repeat polymorphism [GGCGGG] in the promoter region of ALOX5 has been implicated as an important marker for inflammatory diseases. We developed a pyrosequencing assay to genotype the ALOX5 short tandem repeat polymorphism using pyrosequencing technology that will make assessing this important genetic marker in large, diverse populations more accessible than using current methods. We used a nested polymerase chain reaction approach to amplify DNA for pyrosequencing. Population allele frequencies were assessed in two cohorts of previously collected human DNA samples with 188 and 1032 samples, respectively. Sixteen genetic samples with known genotypes were used to confirm the accuracy of the method. Genotypes were 100% concordant with samples of known genotype. Genotype frequencies in European American, Hispanic, and African American agreed with previously published results (wild-type homozygotes 66%, 64%, and 19%, respectively). The method presented here will facilitate both genetic association and pharmacogenomic research on this polymorphism in large samples that are ethnically and/or racially admixed.

Development of batch-culture enrichment coupled to molecular detection for screening of natural and man-made environments in search of anammox bacteria for N-removal bioreactors systems

This investigation probed for anammox bacterial populations that would be suitable to start-up a biological reactor for N-removal. Samples of sludge and sediments from different environments were screened and used as inoculum for enrichment of anammox bacteria in batch cultures. Enrichments were monitored in order to detect anammox bacteria or their potential activity. Candidatus “Brocadia anammoxidans” was successfully enriched, detected, and identified in five of the twelve batch cultures. Furthermore, this organism was retrieved for the first time from a brackish environment. Wide-range primers used in several Polymerase Chain Reaction (PCR) attempts were unable to successfully amplify the 16S rRNA sequence from anammox populations, but were used to search for hypothetical ecological partners of anammox. A nested PCR approach with specific primers was also employed since conventional PCR was unable to amplify anammox DNA from the inocula of the successful enrichments. However, it was impossible to obtain optimal results with the different strategies utilized to improve PCR performance (higher annealing temperature or more specific primers), and only the primer set Amx368F-Amx820R resulted in an acceptable balance between both specificity and sensitivity. Although the enrichment process is relatively slow and requires lengthy incubation periods, it proved to be useful as the molecular analyses were not sensitive enough to detect anammox in the original samples or even after short enrichment periods. Therefore, a batch enrichment procedure coupled with molecular techniques was an appropriate approach to achieve successful inocula for starting-up anammox biological reactor.

Evaluation of the Use of Monoclonal Antibodies and Nested PCR for Noninvasive Prenatal Diagnosis of Hemoglobinopathies in India

Our purpose was to develop and evaluate isolation and enrichment of fetal erythroblasts and a nested polymerase chain reaction (PCR) approach using fetal erythroblasts for detecting the beta-globin gene mutations for a noninvasive prenatal diagnosis of hemoglobinopathies. Maternal blood at different periods of gestation was layered on a Percoll density gradient for enrichment of fetal nucleated RBCs (NRBCs). A combination of 3 monoclonal antibodies (CD45-peridinin chlorophyll protein, glycophorin A-phycoerythrin, and anti-hemoglobin F-fluorescein isothiocyanate) was used for flow cytometric sorting of fetal NRBCs from enriched cells. Different nested PCR-based approaches were used for identification of fetal mutations. Owing to heterogeneity of beta-thalassemia mutations in the population of India, we had to screen for 12 mutations and were able to give an accurate diagnosis in 84 (84.0%) of 100 cases when compared with chorionic villus sampling or cordocentesis and DNA analysis.This nested PCR approach enabled amplification of small quantities of DNA from fetal erythroblasts, providing a cost-effective method for noninvasive diagnosis.

Evaluation of a Nested-PCR assay based on the phosphoglucosamine mutase gene ( glmM) for the detection of Helicobacter pylori from raw milk

Helicobacter pylori is an organism widespread in the human population and sometimes responsible for serious illnesses. Since H. pylori has been detected in Italy from an high percentage of sheep milk samples, it has been hypothesized that contaminated milk, may act as a vehicle of transmission of the microorganism to humans. In this work, a Nested Polymerase Chain Reaction approach has been used to detect H. pylori phosphoglucosamine mutase gene ( glmM) from sheep, goat and cow milk artificially contaminated with wild H. pylori strains isolated from human gastric biopsies and the reference strain ( H. pylori ATCC 43504). The technique showed a high sensitivity of 3 CFU/ml and proved to be both specific and rapid, The authors suggest that it could be used as a sensitive method for a rapid screening of sheep, goat and cow milk samples during the microbiological control of these large consumed foods.

Development and Validation of a Multiplex PCR-Based Assay for the Upper Respiratory Tract Bacterial Pathogens Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis.

Background: Conventional simplex polymerase chain reaction (PCR)-based assays are limited in that they only provide for the detection of a single infectious agent. Many clinical diseases, however, present in a nonspecific, or syndromic, fashion, thereby necessitating the simultaneous assessment of multiple pathogens. Panel-based molecular diagnostic testing can be accomplished by the development of multiplex PCR-based assays, which can detect, individually or severally, different pathogens that are associated with syndromic illness. As part of a larger program of panel development, an assay that can simultaneously detect Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis was developed. These organisms were chosen as they are the most common bacterial pathogens associated with both the acute and chronic forms of otitis media; they are also responsible for a high percentage of sinus infections in both children and adults. In addition, H. influenzae and S. pneumoniae are commonly associated with septic meningitits. Methods and Results: Multiple individual PCR-based assays were developed for each of the three target organisms which were then evaluated for sensitivity and specificity. Utilizing the simplex assays that met our designated performance criteria, a matrix style approach was used to develop a duplex H. influenzae-S. pneumoniae assay. The duplex assay was then used as a single component in the development of a triplex assay, wherein the various M. catarrhalis primer-probe sets were tested for compatibility with the existing assay. A single-step PCR protocol, with species-specific primers for each of the three target organisms and a liquid hybridization-gel retardation amplimer detection system, was developed, which amplifies and then discriminates among each of the amplification products according to size. This assay is able to detect all three organisms in a specific manner, either individually or severally. Dilutional experiments indicate a detection limit of 10 femtograms (fg)(6-7 genomic equivalents) or less of genomic DNA for each of the three microorganisms regardless of the presence of irrelevant DNA. Conclusions: The reliance on individual, robust, species-specific primers and the avoidance of a nested PCR approach make this bacterial multiplex assay suitable for use in the clinical laboratory. This assay has proved useful in both research and patient care applications.

Specific Detection of Pacific Oyster (Crassostrea gigas) Larvae in Plankton Samples Using Nested Polymerase Chain Reaction

Management of sustainable Pacific oyster fisheries would be assisted by an early, rapid, and accurate means of detecting their planktonic larvae. Reported here is an approach, based on polymerase chain reaction (PCR), for the detection of Pacific oyster larvae in plankton samples. Species-specific primers were designed by comparing partial mitochondrial cytochrome oxidase subunit I (COI) sequences from Crassostrea gigas, with other members of the family Ostreidae including those of Crassostrea angulata. Assay specificity was empirically validated through screening DNA samples obtained from several species of oysters. The assay was specific as only C. gigas samples returned PCR-positive results. A nested PCR approach could consistently detect 5 or more D-hinge-stage larvae spiked into a background of about 146 mg of plankton. The assay does not require prior sorting of larvae. We conclude that the assay could be used to screen environmental and ballast water samples, although further specificity testing against local bivalve species is recommended in new locations.

Viral Gastroenteritis in Mongolian Infants

Viral Gastroenteritis in Mongolian Infants

A new nested polymerase chain reaction method very efficient in detecting Plasmodium and Haemoproteus infections from avian blood.

Recently, several polymerase chain reaction (PCR)-based methods for detection and genetic identification of haemosporidian parasites in avian blood have been developed. Most of these have considerably higher sensitivity compared with traditional microscope-based examinations of blood smears. These new methods have already had a strong impact on several aspects of research on avian blood parasites. In this study, we present a new nested PCR approach, building on a previously published PCR method, which has significantly improved performance. We compare the new method with some existing assays and show, by sequence-based data, that the higher detection rate is mainly due to superior detection of Plasmodium spp. infections, which often are of low intensity and, therefore, hard to detect with other methods.

Utility of the Cryptosporidium oocyst wall protein (COWP) gene in a nested PCR approach for detection infection in cattle.

A preliminary molecular epidemiological study was carried out to investigate the utility of the Cryptosporidium oocyst wall protein (COWP) gene in the detection of Cryptosporidium oocysts in fecal samples. A nested polymerase chain reaction (PCR) approach using COWP gene primers was adopted for this purpose. Fecal samples were spiked with each of 1, 10, and 100 oocysts of C. parvum, four samples for each number, and the DNA was extracted from each sample using a glassbead method. The presence of oocysts was determined using the nested PCR with COWP gene primers, and the limit of detection of oocysts by the PCR was determined. The limit of detection was 100 oocysts spiked in 1 ml of fecal material (50% sold material) (four positives/four samples tested). Seventy-five percent of DNA extracted samples spiked with 1 and 10 oocysts was positive by the PCR (three positives/four samples tested). Based on this, small sample size using the COWP gene primers with a nested PCR analysis could reliably identify infected animals rather conveniently and accurately.