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BACKGROUND AND PURPOSE: The predominant cause of candidiasis was Candida albicans which has recently changed to non-Candida albicans Candida (NCAC) (i.e., Candida spp. other than the C. albicans). The NCAC spp., earlier considered non-pathogenic or minimally virulent, are now considered a primary cause of morbidity and mortality in immunocompromised individuals. Given the NCAC spp.has become more common in clinical cases, this study aimed to determine the prevalence of NCAC spp. in different clinical specimens and assess a few of their virulence factors. MATERIALS AND METHODS: Routine samples for bacterial culture and sensitivity that showed colony characteristics, like Candida on Blood Agar and microscopic features resembling Candida spp., were processed further. Candida isolates underwent tests for chlamydospore formation and biochemical tests, including sugar fermentation and sugar assimilation tests. These were grown at 42oC, and their colony color was identified using HiCromeTM Candida Differential Agar (HiMedia Laboratories Pvt. Ltd., Mumbai, India), HiCandida TM Identification Kit (HiMedia Laboratories Pvt. Ltd., Mumbai, India), and VITEK-2® Compact (Biomérieux, France). Virulence factors, such as adherence to buccal epithelial cells (ABEC), biofilm formation, hemolytic activity, and production of coagulase enzyme were also tested. RESULTS: Mean age of the patients was 38.46 years with a male-female ratio of 1.36:1. In total, 137 Candida isolates were recovered; 45.3%, 19.7%, and 13.9% of the isolates were isolated from urine, vaginal swabs, and oropharyngeal swabs, respectively. Moreover, 55 (40.1%) isolates were those of C. albicans and 82 (59.9%) isolates belonged to NCAC spp., with C. tropicalis (23.4%) contributing highest among NCAC species. Furthermore, C. albicans (3; 50%) was the most common spp. in cases of candidemia. Haemolysin production (85.5%) and ABEC (78.2%) were the major virulence factors in C. albicans. C. tropicalis (59.4%) and C. dubliniensis (50%) showed maximum ABEC. Biofilm forming capacity was higher in C. tropicalis (78.1%) than C. albicans (67%). CONCLUSION: Results of this study suggest varied prevalence and virulence based on geographical locations, even within a subcontinent. It clearly indicates the emergence of the NCAC spp. and their predominance in different body fluids. Identification of Candida to the spp. level should become a routine in all laboratories.
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INTRODUCTION: The cases of cryptococcal meningitis and other forms of cryptococcosis have increased in recent time and the present scenario of the condition with significant morbidity and mortality is actually posing a serious threat to the community, so an early and prompt diagnosis is necessary to prevent serious complications and thus improving the overall disease outcome. AIM: Comparison of diagnostic efficacy of nested Polymerase Chain Reaction (PCR) with Latex Agglutination Test (LAT) in the Cerebro Spinal Fluid (CSF) samples of the cases of meningitis in HIV positive and negative cases. MATERIALS AND METHODS: We have compared the diagnostic efficacy of Latex Agglutination Test (LAT) with nested Polymerase Chain Reaction (PCR) in 200 Cerebrospinal Fluid (CSF) samples, including 14 HIV positive also, in the cases of suspected cryptococcal meningitis. Nested PCR was done in all cases reporting positive by LAT and results were then compared with that of India ink and culture on Sabouraud Dextrose Agar (SDA), and the isolates were further identified by urease, nitrate and sugar assimilation tests. RESULTS: Of the 200 cases, including 14 HIV positive, LAT was positive in 46 cases while 154 were negative. Out of these 46 LAT positive cases, nested PCR was positive in 40 cases only, while culture and India ink was positive in 38 and 33 cases respectively. Majority of the cases, 30 (65.2%) were between age group 21-50 years, while 2 (4.3%) in 0-20, and 14 (30.4%) in 51-80 years age group. CONCLUSION: Although negative staining like India ink and nigrosin are most widely used techniques, but these suffer with subjective error. Rapid method like LAT is available but it always has the scope of false positive and negative results. In such cases nested PCR can help in establishing final diagnosis.
ABSTRACT
BACKGROUND: This study was designed for comparative evaluation of two relatively newer recombinant hydrophilic antigens, rK9 and rK26 of Leishmania chagasi along with rK39 (a 39-aminoacid-repetitive immunodominant B-cell epitope of kinesin-related antigen from L. chagasi) and crude soluble antigen (CSA) for the serodiagnosis of Indian visceral leishmaniasis (VL) patients by quantitative ELISA. METHODOLOGY: In the present study a total of 80 subjects comprising of 55 confirmed VL cases and 25 endemic controls (EC) were subjected to ELISA using four different antigens, namely rK9, rK26, rK39 and CSA (derived from Leishmania donovani promastigotes). RESULTS: Sensitivity was as follows: 78% (95%CI 63-100%) for rK9, 38% (95%CI 28-59%) for rK26, 100% for rK39, and 80% (95% CI 65-100%) for CSA. The specificity of rK9, rK26, rK39 and CSA was found to be 84% (95%CI 61-100%), 80% (95%CI 56-100%), 96% (95%CI 75-100%) and 72% (95%CI 49-100%), respectively. CONCLUSIONS: rK39 was observed to be the most suitable antigen as compared to rK26 and rK9 whereas rK9 performed better than rK26. Hence rK9 antigen may either be used as an adjunct to rK39 for accurate diagnosis of VL or may be used in the absence or non-availability of rK39 antigen for the serodiagnosis.