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1.  Predicting Extensively Drug-Resistant Mycobacterium tuberculosis Phenotypes with Genetic Mutations 
Journal of Clinical Microbiology  2014;52(3):781-789.
Molecular diagnostic methods based on the detection of mutations conferring drug resistance are promising technologies for rapidly detecting multidrug-/extensively drug-resistant tuberculosis (M/XDR TB), but large studies of mutations as markers of resistance are rare. The Global Consortium for Drug-Resistant TB Diagnostics analyzed 417 Mycobacterium tuberculosis isolates from multinational sites with a high prevalence of drug resistance to determine the sensitivities and specificities of mutations associated with M/XDR TB to inform the development of rapid diagnostic methods. We collected M/XDR TB isolates from regions of high TB burden in India, Moldova, the Philippines, and South Africa. The isolates underwent standardized phenotypic drug susceptibility testing (DST) to isoniazid (INH), rifampin (RIF), moxifloxacin (MOX), ofloxacin (OFX), amikacin (AMK), kanamycin (KAN), and capreomycin (CAP) using MGIT 960 and WHO-recommended critical concentrations. Eight genes (katG, inhA, rpoB, gyrA, gyrB, rrs, eis, and tlyA) were sequenced using Sanger sequencing. Three hundred seventy isolates were INHr, 356 were RIFr, 292 were MOXr/OFXr, 230 were AMKr, 219 were CAPr, and 286 were KANr. Four single nucleotide polymorphisms (SNPs) in katG/inhA had a combined sensitivity of 96% and specificities of 97 to 100% for the detection of INHr. Eleven SNPs in rpoB had a combined sensitivity of 98% for RIFr. Eight SNPs in gyrA codons 88 to 94 had sensitivities of 90% for MOXr/OFXr. The rrs 1401/1484 SNPs had 89 to 90% sensitivity for detecting AMKr/CAPr but 71% sensitivity for KANr. Adding eis promoter SNPs increased the sensitivity to 93% for detecting AMKr and to 91% for detecting KANr. Approximately 30 SNPs in six genes predicted clinically relevant XDR-TB phenotypes with 90 to 98% sensitivity and almost 100% specificity.
PMCID: PMC3957771  PMID: 24353002
2.  Spectrum of Bacterial Colonization Associated with Urothelial Cells from Patients with Chronic Lower Urinary Tract Symptoms 
Journal of Clinical Microbiology  2013;51(7):2054-2062.
Chronic lower urinary tract symptoms (LUTS), such as urgency and incontinence, are common, especially among the elderly, but their etiology is often obscure. Recent studies of acute urinary tract infections implicated invasion by Escherichia coli into the cytoplasm of urothelial cells, with persistence of long-term bacterial reservoirs, but the role of infection in chronic LUTS is unknown. We conducted a large prospective study with eligible patients with LUTS and controls over a 3-year period, comparing routine urine cultures of planktonic bacteria with cultures of shed urothelial cells concentrated in centrifuged urinary sediments. This comparison revealed large numbers of bacteria undetected by routine cultures. Next, we typed the bacterial species cultured from patient and control sediments under both aerobic and anaerobic conditions, and we found that the two groups had complex but significantly distinct profiles of bacteria associated with their shed bladder epithelial cells. Strikingly, E. coli, the organism most responsible for acute urinary tract infections, was not the only or even the main offending pathogen in this more-chronic condition. Antibiotic protection assays with shed patient cells and in vitro infection studies using patient-derived strains in cell culture suggested that LUTS-associated bacteria are within or extremely closely associated with shed epithelial cells, which explains how routine cultures might fail to detect them. These data have strong implications for the need to rethink our common diagnoses and treatments of chronic urinary tract symptoms.
PMCID: PMC3697662  PMID: 23596238
3.  Next-Generation Ion Torrent Sequencing of Drug Resistance Mutations in Mycobacterium tuberculosis Strains 
Journal of Clinical Microbiology  2012;50(12):3831-3837.
A novel protocol for full-length Mycobacterium tuberculosis gene analysis of first- and second-line drug resistance was developed using the Ion Torrent Personal Genome Machine (PGM). Five genes—rpoB (rifampin), katG (isoniazid), pncA (pyrazinamide), gyrA (ofloxacin/fluoroquinolone), and rrs (aminoglycosides)—were amplified and sequenced, and results were compared to those obtained by genotypic Hain line probe assay (LPA) and phenotypic Bactec MGIT 960 analysis using 26 geographically diverse South African clinical isolates collected between July and November 2011. Ion Torrent sequencing exhibited 100% (26/26) concordance to phenotypic resistance obtained by MGIT 960 culture and genotypic rpoB and katG results by LPA. In several rifampin-resistant isolates, Ion Torrent sequencing revealed uncommon substitutions (H526R and D516G) that did not have a defined mutation by LPA. Importantly, previously uncharacterized mutations in rpoB (V194I), rrs (G878A), and pncA (Q122Stop) genes were observed. Ion Torrent sequencing may facilitate tracking and monitoring geographically diverse multidrug-resistant and extensively drug-resistant strains and could potentially be integrated into selected regional and reference settings throughout Africa, India, and China.
PMCID: PMC3502959  PMID: 22972833
4.  Molecular Characterization and Second-Line Antituberculosis Drug Resistance Patterns of Multidrug-Resistant Mycobacterium tuberculosis Isolates from the Northern Region of South Africa 
Journal of Clinical Microbiology  2012;50(9):2857-2862.
Despite South Africa being one of the high-burden multidrug-resistant tuberculosis (MDR-TB) countries, information regarding the population structure of drug-resistant Mycobacterium tuberculosis strains is limited from many regions of South Africa. This study investigated the population structure and transmission patterns of drug-resistant M. tuberculosis isolates in a high-burden setting of South Africa as well as the possible association of genotypes with drug resistance and demographic characteristics. A total of 336 consecutive MDR-TB isolates from four provinces of South Africa were genotyped using spoligotyping and mycobacterial interspersed repetitive-unit–variable number tandem repeat (MIRU-VNTR) typing. Drug susceptibility testing for ofloxacin, kanamycin, and capreomycin was performed using the agar proportion method. The results showed that 4.8% of MDR-TB isolates were resistant to ofloxacin, 2.7% were resistant to kanamycin, and 4.5% were resistant to capreomycin, while 7.1% were extensively drug resistant (XDR), and the remaining 83.6% were susceptible to all of the second-line drugs tested. Spoligotyping grouped 90.8% of the isolates into 25 clusters, while 9.2% isolates were unclustered. Ninety-one percent of the 336 isolates were assigned to 21 previously described shared types, with the Beijing family being the predominant genotype in the North-West and Limpopo Provinces, while the EAI1_SOM family was the predominant genotype in the Gauteng and Mpumalanga Provinces. No association was found between genotypes and specific drug resistance patterns or demographic information. The high level of diversity and the geographical distribution of the drug-resistant M. tuberculosis isolates in this study suggest that the transmission of TB in the study settings is not caused by the clonal spread of a specific M. tuberculosis strain.
PMCID: PMC3421812  PMID: 22649019
5.  Possible Laboratory Contamination Leads to Incorrect Reporting of Vibrio cholerae O1 and Initiates an Outbreak Response 
Journal of Clinical Microbiology  2012;50(2):480-482.
Vibrio cholerae O1 in a river water specimen in South Africa was reported, and a public health response followed in order to prevent an outbreak. Further investigation determined this to be a pseudoalert of V. cholerae O1, possibly linked to laboratory contamination. Following culture of bacteria from the water specimen, the testing laboratory possibly contaminated the culture with a V. cholerae O1 reference strain and then mistakenly reported isolation of V. cholerae O1.
PMCID: PMC3264189  PMID: 22162543
6.  Performance Characteristics and Comparison of Abbott and artus Real-Time Systems for Hepatitis B Virus DNA Quantification ▿  
Journal of Clinical Microbiology  2011;49(9):3215-3221.
Virological monitoring of hepatitis B virus (HBV) DNA is critical to the management of HBV infection. With several HBV DNA quantification assays available, it is important to use the most efficient testing system for virological monitoring. In this study, we evaluated the performance characteristics and comparability of three HBV DNA quantification systems: Abbott HBV real-time PCR (Abbott PCR), artus HBV real-time PCR with QIAamp DNA blood kit purification (artus-DB), and artus HBV real-time PCR with the QIAamp DSP virus kit purification (artus-DSP). The lower limits of detection of these systems were established against the WHO international standards for HBV DNA and were found to be 1.43, 82, and 9 IU/ml, respectively. The intra-assay and interassay coefficients of variation of plasma samples (1 to 6 log10 IU/ml) ranged between 0.05 to 8.34% and 0.16 to 3.48% for the Abbott PCR, 1.53 to 26.85% and 0.50 to 12.89% for artus-DB, and 0.29 to 7.42% and 0.94 to 3.01% for artus-DSP, respectively. Ninety HBV clinical samples were used for comparison of assays, and paired quantitative results showed strong correlation by linear regression analysis (artus-DB with Abbott PCR, r = 0.95; Abbott PCR with artus-DSP, r = 0.97; and artus-DSP with artus-DB, r = 0.94). Bland-Altman analysis showed a good level of agreement for Abbott PCR and artus-DSP, with a mean difference of 0.10 log10 IU/ml and limits of agreement of −0.91 to 1.11 log10 IU/ml. No genotype-specific bias was seen in all three systems for HBV genotypes A, C, and D, which are predominant in this region. This finding illustrates that the Abbott real-time HBV and artus-DSP systems show more comparable performance than the artus-DB system, meeting the current guidelines for assays to be used in the management of hepatitis B.
PMCID: PMC3165604  PMID: 21795507
7.  Genetic Characterization of Multidrug-Resistant, Extended-Spectrum- β-Lactamase-Producing Vibrio cholerae O1 Outbreak Strains, Mpumalanga, South Africa, 2008 ▿ †  
Journal of Clinical Microbiology  2011;49(8):2976-2979.
Thirty-one antimicrobial-resistant, extended-spectrum-β-lactamase-producing strains of Vibrio cholerae O1 serotype Ogawa associated with an outbreak of cholera in South Africa (2008) were investigated. Ten selected cholera strains were PCR positive for the SXT element, harbored mutations in the quinolone resistance-determining regions of GyrA (Ser83-Ile) and ParC (Ser85-Leu), and produced TEM-63 β-lactamase.
PMCID: PMC3147719  PMID: 21653763
8.  Evaluation of TBc Identification Immunochromatographic Assay for Rapid Identification of Mycobacterium tuberculosis Complex in Samples from Broth Cultures▿ 
Journal of Clinical Microbiology  2011;49(5):1939-1942.
Tuberculosis (TB) is a disease of major public health concern worldwide, especially in developing countries. In addition, the human immunodeficiency virus (HIV) epidemic has increased the incidence of infection with nontuberculous mycobacteria (NTM). Rapid, accurate, and simple methods for differentiation of Mycobacterium tuberculosis complex (MTBC) isolates from NTM is greatly needed for successful control of the TB epidemic. This study was done to evaluate the clinical performance of the BD MGIT TBc identification test (TBc ID) for rapid identification of MTBC in samples from broth cultures. A total of 229 Ziehl-Neelsen (ZN) stain-positive MGIT cultures were tested using the TBc ID test, and the results were compared with those of the AccuProbe MTBC identification test (GenProbe, San Diego, CA). The agreement between the TBc ID test and the AccuProbe assay was 96% (kappa = 0.92; confidence interval [CI] = 0.869 to 0.971). The sensitivity, specificity, and negative and positive predictive values of the TBc ID test compared to the AccuProbe assay were 100%, 92.4%, 100%, and 92.2%, respectively. After additional molecular testing, the agreement between the two methods increased to 97.8% (kappa = 0.96; CI = 0.917 to 0.994), and the specificity and positive predictive value increased to 95.6% and 95.7%, respectively. The TBc ID test is a simple, sensitive, and specific test for identification of MTBC in samples from acid-fast bacillus (AFB) smear-positive cultures. The TBc ID test could be a good alternative to the AccuProbe test in TB diagnostic laboratories.
PMCID: PMC3122657  PMID: 21411594
9.  Isolation and Detection of Campylobacter concisus from Saliva of Healthy Individuals and Patients with Inflammatory Bowel Disease▿  
Journal of Clinical Microbiology  2010;48(8):2965-2967.
The presence of Campylobacter concisus in the saliva of healthy individuals and patients with inflammatory bowel disease (IBD) was examined. C. concisus was detected in 97% of the healthy individuals and 100% of the patients with IBD tested. The C. concisus culture positivity rate in younger children was significantly lower than that in the other age groups.
PMCID: PMC2916630  PMID: 20519479
10.  Regional Profiling for Determination of Genotype Diversity of Mastitis-Specific Staphylococcus aureus Lineage in Canada by Use of Clumping Factor A, Pulsed-Field Gel Electrophoresis, and spa Typing▿  
Journal of Clinical Microbiology  2009;48(2):375-386.
One of the major concerns in global public health and the dairy industry is the emergence of host-specific virulent Staphylococcus aureus strains. The high degree of stability of the species genome renders detection of genetic microvariations difficult. Thus, approaches for the rapid tracking of specialized lineages are urgently needed. We used clumping factor A (clfA) to profile 87 bovine mastitis isolates from four regions in Canada and compared the results to those obtained by pulsed-field gel electrophoresis (PFGE) and spa typing. Twenty-five pulsotypes were obtained by PFGE with an index of discrimination of 0.91. These were assigned to six PFGE lineage groups A to F and seven spa types, including two novel ones. Group A had 48.3% of the isolates and group D had 43.7% of the isolates, while only 8% of the isolates were variable. The results of antimicrobial susceptibility testing indicated that all isolates were sensitive to methicillin and the non-beta-lactam antibiotics, while three isolates were resistant to penicillin and one isolate was resistant to tetracycline. All isolates had the clfA gene and belonged to 20 clfA repeat types with an index of discrimination of 0.90. The dominant clfA types, types X, Q, C, and Z, formed 82% and 43% of PFGE groups A and D, respectively, and had copy numbers that varied only within a narrow range of between 46 and 52 copies, implying clonal selection. The rest were variable and region specific. Furthermore, the dominant groups contained subpopulations in different regions across Canada. Sequence information confirmed the relatedness obtained by the use of clfA repeat copy numbers and other methods and further revealed the occurrence of full-repeat deletions and conserved host-specific codon-triplet position biases at 18-bp units. Thus, concordant with the results of PFGE and spa typing, clfA typing proved useful for revealing the clonal nature of the mastitis isolate lineage and for the rapid profiling of subpopulations with comparable discriminatory powers.
PMCID: PMC2815643  PMID: 19955267
11.  Similarity of Bacterial Populations in Saliva from African-American Mother-Child Dyads▿  
Journal of Clinical Microbiology  2007;45(9):3082-3085.
Using PCR-based denaturing gradient gel electrophoresis analyses of oral bacterial samples in 20 mother-child dyads, this study demonstrated a high degree of similarity of bacterial compositions between the mothers and their children; the two may share as much as 94% of their oral bacterial spectra, including cariogenic species.
PMCID: PMC2045297  PMID: 17634300
12.  Evaluation of the New Chromogenic Medium Candida ID 2 for Isolation and Identification of Candida albicans and Other Medically Important Candida Species 
Journal of Clinical Microbiology  2006;44(9):3340-3345.
The usefulness of Candida ID 2 (CAID2) reformulated medium (bioMérieux, France) has been compared with that of the former Candida ID (CAID; bioMérieux), Albicans ID 2 (ALB2; bioMérieux), and CHROMagar Candida (CAC; Chromagar, France) chromogenic media for the isolation and presumptive identification of clinically relevant yeasts. Three hundred forty-five stock strains from culture collections, and 103 fresh isolates from different clinical specimens were evaluated. CAID2 permitted differentiation based on colony color between Candida albicans (cobalt blue; sensitivity, 91.7%; specificity, 97.2%) and Candida dubliniensis (turquoise blue; sensitivity, 97.9%; specificity, 96.6%). Candida tropicalis gave distinguishable pink-bluish colonies in 97.4% of the strains in CAID2 (sensitivity, 97.4%; specificity, 100%); the same proportion was reached in CAC, where colonies were blue-gray (sensitivity, 97.4%; specificity, 98.7%). CAC and CAID2 showed 100% sensitivity values for the identification of Candida krusei. However, with CAID2, experience is required to differentiate the downy aspect of the white colonies of C. krusei from other white-colony-forming species. The new CAID2 medium is a good candidate to replace CAID and ALB2, and it compares well to CAC for culture and presumptive identification of clinically relevant Candida species. CAID2 showed better results than CAC in some aspects, such as quicker growth and color development of colonies from clinical specimens, detection of mixed cultures, and presumptive differentiation between C. albicans and C. dubliniensis.
PMCID: PMC1594741  PMID: 16954270
13.  Supplementation of CHROMagar Candida Medium with Pal's Medium for Rapid Identification of Candida dubliniensis 
Journal of Clinical Microbiology  2005;43(11):5768-5770.
CHROMagar Candida medium is used for the isolation and identification of Candida species, but it does not differentiate Candida albicans from Candida dubliniensis. This differentiation can be achieved by using Pal's agar, which cannot be used in primary isolation. We have combined both media to obtain a new medium that can be used for the isolation and identification of C. dubliniensis in primary cultures.
PMCID: PMC1287798  PMID: 16272515
14.  A Novel Shigella dysenteriae Serovar Isolated in Canada 
Journal of Clinical Microbiology  2005;43(2):740-744.
The etiological agent most commonly associated with bacillary dysentery is Shigella. As part of its mandate, the Bacteriology and Enteric Disease Program of Health Canada identifies and serotypes unusual isolates of Shigella received from provincial laboratories of public health. In this report, six unusual isolates from three provinces were analyzed biochemically and serologically using slide and tube agglutinations and molecularly using standard pulsed-filed gel electrophoresis (PFGE), PCR, and PCR-restriction fragment length polymorphism (RFLP) techniques. All six isolates were identical. PFGE analysis grouped these strains; biochemically, they were mannitol negative and consistent with the profile of Shigella. Serologically, these strains produced weak reactions in Shigella dysenteriae serovars 4 and 16 and Escherichia coli O159 and O173 antisera. Molecular serotyping by PCR-RFLP of the rfb gene produced an S. dysenteriae serovar 2/E. coli O112ac pattern. They were positive by PCR for ipaH and ial enteroinvasive genes but negative for all other genes tested. Antiserum was prepared from one of the isolates and tested against Shigella and E. coli reference strains as well as the other isolates. The antiserum reacted with the five remaining isolates and showed cross-reactivity with S. dysenteriae serovars 1, 4, and 16; Shigella flexneri type 3; and E. coli O118, O159, O168, O172, and O173 antigens. Absorbing the sera with E. coli O159 and S. dysenteriae serovar 4 antigen removed all cross-reactions and only slightly reduced the homologous titer. Based on biochemical, molecular, and complete serological analysis, we propose that these six isolates represent a new provisional serovar of S. dysenteriae, type strain BEDP 02-5104.
PMCID: PMC548111  PMID: 15695673
15.  Laboratory Evaluation of a Fully Automated Chemiluminescence Immunoassay for Rapid Detection of HBsAg, Antibodies to HBsAg, and Antibodies to Hepatitis C Virus 
Journal of Clinical Microbiology  2004;42(2):610-617.
The performance of a fully automated, random access, enhanced chemiluminescence immunoassay (Ortho/ECi) for the detection of antibody to hepatitis C virus (HCV) (anti-HCV), HBsAg, and antibody to HBsAg (anti-HBsAg), in human serum was compared to a Abbott second-generation enzyme immunoassay (EIA 2.0). The Ortho/ECi assays employ an immunometric technique with enhanced chemiluminescence for optimal assay performance. With regard to the study of clinical laboratory performance, six groups of sera prescreened with Abbott EIAs were assayed: anti-HCV-negative samples (n = 318), anti-HCV-positive samples (n = 177), anti-HBsAg-negative samples (n = 241), anti-HBsAg-positive samples (n = 239), HBsAg-positive samples (n = 158), and HBsAg-negative samples (n = 312). Sera with discrepant results in the two serological assays were resolved by confirmatory tests. Sera with indeterminate results by one or more confirmatory tests were evaluated by reviewing medical records. The overall concordance between the Ortho/ECi assay and the Abbott EIA were 97.78, 93.54, and 97.66% for anti-HCV antibodies, anti-HBsAg antibodies, and HBsAg, respectively. After resolving the discrepancies, the specificities of the new assay for anti-HCV and anti-HBsAg antibodies and HBsAg were 98.1, 92.8, and 100%, respectively. The sensitivities of the new assay for anti-HCV, anti-HBsAg, and HBsAg were 100, 98.8, and 97.4%, respectively. In conclusion, The Ortho/ECi assays for diagnosis of HCV and hepatitis B virus (HBV) infections are highly specific and sensitive assays. The rapid turnaround time, random access, full automation, and high throughput make it an effective assay system for clinical laboratory diagnosis of HCV and HBV infections.
PMCID: PMC344481  PMID: 14766824
16.  Evaluation of Dipstick Serologic Tests for Diagnosis of Brucellosis and Typhoid Fever in Egypt 
Journal of Clinical Microbiology  2002;40(9):3509-3511.
Two dipstick assays for the detection of Brucella- and typhoid-specific immunoglobulin M, recently developed by the Royal Tropical Institute of The Netherlands, were evaluated by use of 85 plasma samples from Egyptian patients. Both dipsticks were simple and accurate rapid diagnostic assays, and they can be useful adjuncts for the diagnosis of typhoid fever and brucellosis.
PMCID: PMC130816  PMID: 12202606
17.  Development of a Canadian Standardized Protocol for Subtyping Methicillin-Resistant Staphylococcus aureus Using Pulsed-Field Gel Electrophoresis 
Journal of Clinical Microbiology  2001;39(10):3481-3485.
A panel of 24 methicillin-resistant Staphylococcus aureus strains was distributed to 15 laboratories in Canada to evaluate their in-house pulsed-field gel electrophoresis (PFGE) protocols and interpretation criteria. Attempts to compare fingerprint images using computer-aided analysis were not successful due to variability in individual laboratory PFGE protocols. In addition, individual site interpretation of the fingerprint patterns was inadequate, as 7 of 13 sites (54%) made at least one error in interpreting the fingerprints from the panel. A 2-day standardized PFGE protocol (culture to gel image) was developed and distributed to all of the sites. Each site was requested to use the standardized protocol on five strains from the original panel. Thirteen sites submitted gel images for comparisons. The protocol demonstrated excellent reproducibility and allowed interlaboratory comparisons with Molecular Analyst DST software (Bio-Rad) and 1.5% band tolerance.
PMCID: PMC88375  PMID: 11574559
18.  Rapid Detection of a Schistosoma mansoni Circulating Antigen Excreted in Urine of Infected Individuals by Using a Monoclonal Antibody 
Journal of Clinical Microbiology  1999;37(2):354-357.
Schistosoma circulating antigens were used to indicate the infection intensity and to assess cure. An immunoglobulin G2a (IgG2a) mouse monoclonal antibody was used in a fast dot-enzyme-linked immunosorbent assay (ELISA; FDA) for rapid and simple diagnosis of schistosomiasis in the field. Seven hundred Egyptians were parasitologically examined for Schistosoma mansoni and other parasitic infections. A rectal biopsy was done as a “gold standard” for individuals showing no S. mansoni eggs in their feces. Egg counts were obtained by the Kato smear method for only 100 of 152 individuals with eggs in their feces. Specific anti-schistosome IgG antibodies were evaluated in sera by ELISA. Urine samples from the 700 individuals were tested by FDA for detection of the circulating antigen. The assay showed a sensitivity of 93% among 433 infected individuals and a specificity of 89% among 267 noninfected individuals. FDA showed the highest efficiency of antigen detection (91%) compared with the efficiency of antibody detection by ELISA (75%) and stool analysis (60%). In addition, FDA detected infected patients with 20 eggs/g of feces. Also, the sensitivity of FDA ranged from 90 to 94% among samples from patients with different clinical stages of schistosomiasis. All the assay steps can be completed within 30 min at room temperature for 96 urine samples. The monoclonal antibody identified a 74-kDa antigen in different antigenic extracts of S. mansoni and Schistosoma haematobium and in the urine of infected individuals. In addition, a 30-kDa degradation product was identified only in the urine samples. On the basis of these results, FDA should be used as a rapid tool for the sensitive and specific diagnosis of Schistosoma infection.
PMCID: PMC84306  PMID: 9889217
19.  Identification of an immunodominant 32-kilodalton membrane protein of Leishmania donovani infantum promastigotes suitable for specific diagnosis of Mediterranean visceral leishmaniasis. 
Journal of Clinical Microbiology  1994;32(10):2474-2480.
Sera from 35 patients suffering from Mediterranean visceral leishmaniasis (caused by Leishmania donovani infantum) and 59 patients with various forms of cutaneous leishmaniasis prevalent in the sub-Mediterranean countries (caused by Leishmania major, L. donovani infantum, or Leishmania tropica) were tested by immunoblotting and enzyme-linked immunosorbent assay (ELISA) with both membrane and soluble antigens prepared from L. donovani infantum parasites. Control sera were from healthy children (n = 41), adults with nonleishmanial diseases (n = 40), and patients with Chagas' disease (n = 12). A P32 antigen present in the membrane preparation from L. donovani infantum parasites was recognized by 95% of serum specimens from patients with Mediterranean visceral leishmaniasis but not by serum specimens from patients with cutaneous leishmaniasis or sera from control individuals. An ELISA with electroeluted P32 antigen was found to have a specificity and sensitivity of 94% in the serodiagnosis of Mediterranean visceral leishmaniasis. Healthy children with asymptomatic Leishmania infection were seronegative for the P32 antigen by ELISA. These results suggest that antibodies to P32 antigen develop only in patients with visceral leishmaniasis and that the P32 ELISA may be useful in areas where the disease is endemic for discriminating between patients with this disease and those with other clinical conditions.
PMCID: PMC264086  PMID: 7814485

Results 1-19 (19)