Histoplasmosis masquerading as tuberculosis: A report of three cases in immunocompetent children.

The most common cause of granulomatous lymphadenitis in countries like ours is mycobactrium tuberculosis followed by atypical mycobacterial infection, fungal infections, parasitic infection, cat scratch disease, lymphogranuloma venereum (inguinal lymphadenopathy), and leprosy Here, we present three cases of lymphadenopathy due to histoplasmosis in immunocompetent children. Two of them presented with fever, lymphadenopathy, initially diagnosed as granulomatous lymphadenitis consistent with tuberculosis on FNAC and were put on antitubercular drugs. However, their condition gradually became worse. As the patients continued to deteriorate, subsequent lymph node biopsies were done and diagnosed as histoplasmosis. Third case presented with acute loss of vision with hepatosplenomegaly and lymphadenopathy. Initially considered as acute leukemia, but eventually established as histoplasmosis. Histoplasmosis should be considered as one of the possible causes of granulomatous lymphadenitis in children.

Histological diagnosis of early and suspicious leprosy by in situ PCR.

Leprosy is a chronic mycobacterial disease whose diagnosis is primarily based on clinico-pathological examination and supported by slit skin smears for the presence of acid fast bacilli (AFB). However, definitive diagnosis of early leprosy and those suspected to have the disease but not histologically confirmed pose major public health problems. The present study reports the utility of the in situ Polymerase Chain Reaction amplification (PCR) directed at a 530bp fragment of DNA encoding the 36kd antigen of the causative Mycobacterium leprae for the diagnosis of such patients using skin biopsies of lesions. Twenty five adult patients (aged 15-50yrs) each from the clinical categories of Early and clinically Suspect leprosy were selected for the study after obtaining permission. They had solitary lesions, which were negative for AFB on slit skin smear examination. Routine histopathology confirmed the diagnosis of leprosy in 8/25 (32%) cases in the category of Early leprosy with AFB being seen in 2 biopsies, and in 5/25(20%) cases of Suspect leprosy with AFB being seen in a solitary case. The Direct in situ PCR procedure which was performed in the histologically unconfirmed cases improved the diagnosis with positive results observed in 12/17 (70.6%) cases of Early (p=0.001) and in 12/20 (60%) cases of Suspect Leprosy (p=0.005 indicating the usefulness of the Direct in situ PCR to establish the diagnosis of leprosy in histologically doubtful cases.

Mycobacterium indicus pranii as stand-alone or adjunct immunotherapeutic in treatment of experimental animal tuberculosis.

BACKGROUND & OBJECTIVES: Mycobacterium w (M.w) is a saprophytic cultivable mycobacterium and shares several antigens with M. tuberculosis. It has shown good immunomodulation in leprosy patients. Hence in the present study, the efficacy of M.w immunotherapy, alone or in combination with multi drug chemotherapeutic regimens was investigated against drug sensitive M. tuberculosis H37Rv and three clinical isolates with variable degree of drug resistance in mice. METHODS: BALB/c mice were infected with M. tuberculosis H37Rv (susceptible to all first and second line drugs) and three clinical isolates taken from the epository of the Institute. The dose of 200 bacilli was used for infection via respiratory route in an aerosol chamber. Chemotherapy (5 days/wk) was given one month after infection and the vaccinated group was given a dose of 1x107 bacilli by subcutaneous route. Bacterial load was measured at 4 and 6 wk after initiation of chemotherapy. RESULTS: M.w when given along with chemotherapy (4 and 6 wk) led to a greater reduction in the bacterial load in lungs and other organs of TB infected animals compared to. However, the reduction was significantly (P<0.05) more in terms of colony forming units (cfu) in both organs (lungs and spleen). CONCLUSION: M.w (as immunomodulator) has beneficial therapeutic effect as an adjunct to chemotherapy.

Molecular typing of Mycobacterium leprae strains from northern India using short tandem repeats.

BACKGROUND & OBJECTIVES: Due to the inability to cultivate Mycobacterium leprae in vitro and most cases being paucibacillary, it has been difficult to apply classical genotyping methods to this organism. The objective of this study was therefore, to analyze the diversity among M. leprae strains from Uttar Pradesh, north India, by targeting ten short tandem repeats (STRs) as molecular markers. METHODS: Ninety specimens including 20 biopsies and 70 slit scrappings were collected in TE buffer from leprosy patients, who attended the OPD of National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra, and from villages of Model Rural Health Research Unit (MRHRU) at Ghatampur, Kanpur, Uttar Pradesh. DNA was extracted from these specimens and ten STRs loci were amplified by using published and in-house designed primers. The copy numbers were determined by electrophoretic mobility as well as sequence analysis. Phylogenetic analysis was done on variable number of tandem repeats (VNTRs) data sets using start software. RESULTS: Diversity was observed in the cross-sectional survey of isolates obtained from 90 patients. Allelic index for different loci was found to vary from 0.7 to 0.8 except for rpoT for which allelic index was 0.186. Similarity in fingerprinting profiles observed in specimens from the cases from same house or nearby locations indicated a possible common source of infection. Such analysis was also found to be useful in discriminating the relapse from possible reinfection. INTERPRETATION & CONCLUSIONS: This study led to identification of STRs eliciting polymorphism in north Indian strains of M. leprae. The data suggest that these STRs can be used to study the sources and transmission chain in leprosy, which could be very important in monitoring of the disease dynamics in high endemic foci.

Nocardial mycetoma: diverse clinical presentations.

Nocardia spp are gram-positive, aerobic, acid-fast bacteria which exist as saprophytes in nature. Invasive disseminated infections are particularly common in immunocompromised or debilitated hosts. Superficial infections with Nocardia spp occur as a result of local trauma and contamination of the wound. Clinically, it presents as acute infection (abscesses or cellulitis), mycetoma, or sporotrichoid infection. Differential diagnosis includes eumycetoma, chromomycosis, blastomycosis, coccidioidomycosis, sporotrichosis, tuberculosis, botryomycosis, syphilis, yaws, and neoplasia. Its diagnosis is confirmed by demonstrating the causative organism in exudates (as granules), tissue specimens, or cultures. Early diagnosis will obviate need for drastic surgical measures as early institution of chemotherapy is effective in most patients. However, its diagnosis is often delayed due to diverse clinical presentations and for want of clinical suspicion, particularly in non-endemic areas. This paper presents 4 clinical forms of this not so uncommon disease, emphasizing the importance of high index of clinical suspicion, especially in non-endemic regions; and the significance of repeated examination of exudates for Nocardia granules for an early diagnosis.

Predominance of three copies of tandem repeats in rpoT gene of Mycobacterium leprae from Northern India.

This study has been carried out to get understanding of the origin among the strains of Mycobacterium leprae in patients from Northern India by using number of tandem repeats in rpoT gene as marker. Biopsies were collected from hundred leprosy cases (paucibacillary (PB) as well as multibacillary (MB)) across the spectrum from patients attending clinic at JALMA or diagnosed in Field Unit at Ghatampur (Kanpur). These biopsies were homogenized and DNA was extracted by a physiochemical procedure. rpoT region was amplified by using the primers and conditions earlier published. Among 100 strains from Northern Indian patients, 89% exhibited the presence of three copies of the 6bp tandem repeat in the rpoT gene, while 11% contained four copies. These profiles along with other genotyping data may help in studying the historical spread of leprosy by strains of M. leprae disseminated by various human races that migrated to Northern India from other places of Asian continent.

Analysis of quantitative relationship between viability determination in leprosy by MFP, ATP bioluminescence and gene amplification assay

Two hundred twenty-one untreated, borderline lepromatous/lepromatous (BL/LL) leprosy patients have been investigated for viability by the mouse foot pad method (MFP), adenosine triphosphate (ATP) and polymerase chain reaction (PCR). The biopsies were collected at the beginning of and 12/24 months after treatment. The patient group was treated with a) immunotherapy (BCG/Mw) + MDT; b) MDT + pyrazinamide; c) control MDT; d) MDT + minocycline 100 mg once a month supervised + ofloxacin 400 mg once a month supervised. Biopsies were divided in three parts for use in the mouse foot pad, molecular and ATP investigations. In untreated and treated patients (at 12 and 24 months), there was a general agreement among all three techniques, and PCR and ATP showed higher positivity as compared to MFP. Further, there was good correlation among the viable biomass estimated by bacillary ATP levels, PCR assay and growth in mouse foot pads. The positivity was observed by MFP as well as PCR assay (18-kDa and 36-kDa) from all of the specimens when the ATP content was more than 3.6 pg/million. When the ATP content was below 3.5 pg/million, the positive takes in MFP decreased but the PCR positivity correlated with ATP bioluminescence up to 0.04 pg/million. When the ATP content was even lower, the uptake in the MFP was possibly a matter of chance, while PCR positivity was observed in 96% of the cases. For specimens with undetectable ATP, positivity was seen in 1% of the cases, showing the inability of ATP bioluminescence method to detect low background due to host ATP. PCR signals in some cases could be due to the higher sensitivity of the method or persistence of DNA after bacterial death in some cases. On the whole, the PCR methods even though targeting DNA have shown good correlations with biomass which confirm their usefulness in monitoring therapeutic responses in leprosy.