Diagnostic Approach to Extrapulmonary Tuberculosis by Cartridge-based Nucleic Acid Amplification Test.

BACKGROUND: Tuberculosis (TB) is a highly infectious disease causing millions of cases worldwide. Though pulmonary TB is the most common form of infection, extrapulmonary cases are also very rampant and are responsible for a large number of cases. But the diagnosis of extrapulmonary cases is quite difficult because of varied manifestations and the paucibacillary nature of the infection. Cartridge-based nucleic acid amplification test (CBNAAT) is a simple, rapid test that is very efficient in the early diagnosis of these extrapulmonary cases [extrapulmonary TB (EPTB)]. AIM: A study was done to establish the usefulness of CBNAAT in the early diagnosis of EPTB cases. MATERIALS AND METHODS: A comparative study was conducted in a rural tertiary care hospital in West Bengal, India, for 8 months (July 2021-February 2022). Samples were collected from different sites like pleural fluid, lymph nodes, cerebrospinal fluid (CSF), pus, ascitic fluid, and tissue aspirate and subjected to both CBNAAT and smear staining and examination under a fluorescent microscope. Positive samples were cultured, examined, and compared. RESULT: From 593 samples collected from different sites in suspected cases of EPTB-52 samples were positive by CBNAAT, and six cases showed rifampicin resistance (RIF resistant). Smear staining of the samples by auramine-rhodamine stains and examined under the fluorescent microscope for acid-fast bacilli identifying 33 samples; the rest were negative. Slides showing acid-fast bacilli were cultured on Lowenstein-Jensen media. CONCLUSION: Cartridge-based nucleic acid amplification test (CBNAAT) is a very useful assay for the early diagnosis of extrapulmonary cases as it can accurately identify false negative samples by smear microscopy.

Genomic, morphological, and biochemical analyses of a multi-metal resistant but multi-drug susceptible strain of Bordetella petrii from hospital soil.

Contamination of soil by antibiotics and heavy metals originating from hospital facilities has emerged as a major cause for the development of resistant microbes. We collected soil samples surrounding a hospital effluent and measured the resistance of bacterial isolates against multiple antibiotics and heavy metals. One strain BMCSI 3 was found to be sensitive to all tested antibiotics. However, it was resistant to many heavy metals and metalloids like cadmium, chromium, copper, mercury, arsenic, and others. This strain was motile and potentially spore-forming. Whole-genome shotgun assembly of BMCSI 3 produced 4.95 Mb genome with 4,638 protein-coding genes. The taxonomic and phylogenetic analysis revealed it, to be a Bordetella petrii strain. Multiple genomic islands carrying mobile genetic elements; coding for heavy metal resistant genes, response regulators or transcription factors, transporters, and multi-drug efflux pumps were identified from the genome. A comparative genomic analysis of BMCSI 3 with annotated genomes of other free-living B. petrii revealed the presence of multiple transposable elements and several genes involved in stress response and metabolism. This study provides insights into how genomic reorganization and plasticity results in evolution of heavy metals resistance by acquiring genes from its natural environment.

Filariasis of the breast--an unusual presentaion.

Filariasis of the breast presenting as a breast lump and clinically simulating as breast tumour is an unusual presentation. The present case is of a 30 years old female complaining of breast lump and on fine needle aspiration revealed microfilaria.