ABSTRACT
Leprosy is a chronic infectious disease caused by Mycobacterium leprae. Identification of Mycobacterium leprae is difficult in part due to the inability of the leprosy bacillus to grow in vitro. A number of diagnostic methods for leprosy diagnosis have been proposed. Both serological tests and molecular probes have shown certain potential for detection and identification of Mycobacterium leprae in patients. In this study, we have investigated whether Mycobacterium leprae DNA from the nasal secretion of healthy household contacts and the non contacts could be detected through PCR amplification as a method to study the sub clinical infection in a community. A total of 200 samples, 100 each from contacts and non contacts representing all age groups and sex were included in this study. The M. leprae specific primer (proline-rich region) of pra gene was selected and PCR was performed using extracted DNA from the sample. A total of 13 samples were found to be positive for nasal PCR for pra gene among the male and female contacts out of which 7% were males and 6% were females. Even though several diagnostic tools are available to detect the cases of leprosy, they lack the specificity and sensitivity. PCR technology has demonstrated the improved diagnostic accuracy for epidemiological studies and requires minimal time. Although nasal PCR studies have been reported from many countries it is not usually recommended due to the high percentage of negative results in the contact.
Subject(s)
Asymptomatic Infections/epidemiology , Bodily Secretions/microbiology , Leprosy/diagnosis , Leprosy/epidemiology , Mycobacterium leprae/isolation & purification , Nose/microbiology , Polymerase Chain Reaction/methods , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Female , Humans , Infant , Leprosy/microbiology , Male , Middle Aged , Molecular Diagnostic Techniques/methods , Mycobacterium leprae/genetics , Sensitivity and Specificity , Time Factors , Young AdultABSTRACT
INTRODUCTION: The emergence and rapid spread of blaIMP and blaVIM metallo-beta-lactamase (MBL) producing Gram-negative bacteria causing nosocomial infections are of concern worldwide due to limited treatment options. METHODOLOGY: A total of 179 nonreplicate, consecutive, carbapenem resistant Pseudomonas aeruginosa (61), Acinetobacter baumannii (116), Acinetobacter lwoffii (1) and Pseudomonas stutzeri (1) isolated from patients hospitalized for 48 hours or more were included in the study. The minimum inhibitory concentrations (MIC) to imipenem and meropenem were determined and interpreted according to Clinical Laboratory Standards Institute guidelines. The Modified Hodge Test (MHT) and inhibitor potentiated disk diffusion tests with ethylenediaminetetraacetic acid (EDTA) were used for screening of carbapenamases and MBL production respectively. Polymerase chain reaction (PCR) was performed for the detection of MBL (blaVIM and blaIMP) genes. Gene sequencing was performed for representative isolates. RESULTS: MHT was positive in 94.4% (n = 169). MBL screening with EDTA was positive in 80.4% (n = 144). MBL genes bla VIM and bla IMP were detected in 92 (51.4%) isolates. Bla VIM alone was detected in 89 isolates while two isolates had bla IMP alone. One isolate had both bla VIM and bla IMP. Among the P. aeruginosa, 36 carried the MBL gene. In A. baumannii, 54 carried the MBL gene. Bla VIM was found in P. stutzeri and A. lwoffii isolates. CONCLUSION: Carbapenem resistance in P. aeruginosa and A. baumannii is chiefly mediated by MBL production. The common MBL gene is the blaVIM.
