Multilocus genotyping of Cryptosporidium sp. isolates from human immunodeficiency virus-infected individuals in South India.
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ABSTRACT:
SUBMITTER: Muthusamy D
PROVIDER: S-EPMC1392691 | biostudies-literature | 2006 Feb
REPOSITORIES: biostudies-literature
Publications
Multilocus genotyping of Cryptosporidium sp. isolates from human immunodeficiency virus-infected individuals in South India.
Muthusamy Dheepa D Rao Sitara S SS Ramani Sasirekha S Monica Bindhu B Banerjee Indrani I Abraham Ooriapadickal C OC Mathai Dilip C DC Primrose Beryl B Muliyil Jayaprakash J Wanke Christine A CA Ward Honorine D HD Kang Gagandeep G
Journal of clinical microbiology 20060201 2
This study characterized cryptosporidial infections in 48 human immunodeficiency virus-infected individuals in India by multilocus genotyping. Cryptosporidium hominis, C. parvum, C. felis, C. muris, and C. meleagridis were identified. Cpgp40/15 PCR-restriction fragment length polymorphism identified six subgenotypes. Cryptosporidial diarrhea was associated with decreased CD4 counts, below 200 (P = 0.009), but not high viral loads. ...[more]
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Project description:The genetic analysis of oocysts recovered from the stools of humans and animals infected with Cryptosporidium parvum has consistently shown the existence of two distinct genotypes. One of the genotypes is found exclusively in some human infections, whereas the other genotype is found in human as well as in animal infections. On the basis of these observations and the results of published epidemiological studies with single polymorphic markers, the existence of two separate transmission cycles has been postulated, one exclusively anthroponotic and the other involving both animals and humans. To test this hypothesis, C. parvum isolates of different geographic and host origins were analyzed by using unlinked genetic polymorphisms. A total of 28 isolates originating from Europe, North and South America, and Australia were examined. Isolates clustered into two groups, one comprising both human and animal isolates and the other comprising isolates only of human origin. The absence of recombinant genotypes is consistent with two reproductively isolated populations within the species C. parvum.
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Project description:Listeria monocytogenes is responsible for serious invasive illness associated with consumption of contaminated food and places a significant burden on public health and the agricultural economy. We recently developed a multilocus genotyping (MLGT) assay for high-throughput subtype determination of L. monocytogenes lineage I isolates based on interrogation of single nucleotide polymorphisms (SNPs) via multiplexed primer extension reactions. Here we report the development and validation of two additional MLGT assays that address the need for comprehensive DNA sequence-based subtyping of L. monocytogenes. The first of these novel MLGT assays targeted variation segregating within lineage II, while the second assay combined probes for lineage III strains with probes for strains representing a recently characterized fourth evolutionary lineage (IV) of L. monocytogenes. These assays were based on nucleotide variation identified in >3.8 Mb of comparative DNA sequence and consisted of 115 total probes that differentiated 93% of the 100 haplotypes defined by the multilocus sequence data. MLGT reproducibly typed the 173 isolates used in SNP discovery, and the 10,448 genotypes derived from MLGT analysis of these isolates were consistent with DNA sequence data. Application of the MLGT assays to assess subtype prevalence among isolates from ready-to-eat foods and food-processing facilities indicated a low frequency (6.3%) of epidemic clone subtypes and a substantial population of isolates (>30%) harboring mutations in inlA associated with attenuated virulence in cell culture and animal models. These mutations were restricted to serogroup 1/2 isolates, which may explain the overrepresentation of serotype 4b isolates in human listeriosis cases.
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Project description:BackgroundImmune correlates of tuberculosis (TB) risk in populations infected with human immunodeficiency virus (HIV) remain understudied, despite HIV being associated with a high burden of TB disease. Here we describe plasma cytokine correlates of TB recurrence in a well-characterized cohort of HIV-infected individuals on antiretroviral therapy (ART) with a history of prior TB cure.MethodsStudy participants were drawn from a prospective cohort study initiated at the conclusion of a randomized clinical trial in which individuals presented with untreated HIV infection and active pulmonary TB. At baseline, ART was initiated, and TB successfully cured. Participants were screened for TB recurrence quarterly for up to 4 years. TB recurrent cases (n = 63) were matched to controls (n = 123) on sex, study arm assignment in the original trial, and month of enrollment with a subset of cases sampled longitudinally at several time-points.ResultsThree cytokines were associated with increased rates of TB recurrence in univariate models: interleukin 6 (IL6) (odds ratio [OR] 2.66, 95% confidence interval [CI] 1.34-5.28, P = .005), IP10 (OR 4.62, 95% CI 1.69-12.65, P = .003), monokine induced by IFN-? (MIG) (OR 3.11, 95% CI 1.10-8.82, P = .034). Conversely, interferon ? (IFN?) was associated with decreased TB risk (OR 0.34, 95% CI 0.13-0.87, P = .025). Following multivariate analyses adjusting for covariates IL6, interleukin 1? (IL1?), and interleukin 1R? (IL1R?) were associated with increased risk and IFN? with decreased TB risk. Longitudinal analysis showed that levels of many TB-associated markers, including IL6, IP10, sCD14, and interferon ? (IFN?) are reduced following TB treatment.ConclusionThese data show that TB recurrence, in HIV-infected individuals on ART is predicted by biomarkers of systemic inflammation, many of which are implicated in more rapid HIV disease progression.Clinical trials registrationNCT 01539005.
| S-EPMC5848260 | biostudies-literature