ABSTRACT
Next-generation sequencing (NGS) and the technique of DNA metabarcoding have provided more efficient and comprehensive options for testing water quality compared to traditional methods. Recent studies have shown the efficacy of DNA metabarcoding in characterizing the bacterial microbiomes of varied sources of drinking water, including rivers, reservoirs, wells, tanks, and lakes. We asked whether DNA metabarcoding could be used to characterize the microbiome of different private sources of stored freshwater on the Caribbean Island nation of Antigua and Barbuda. Two replicate water samples were obtained from three different private residential sources in Antigua: a well, an above-ground tank, and a cistern. The bacterial microbiomes of different freshwater sources were assessed using 16S rRNA metabarcoding. We measured both alpha diversity (species diversity within a sample) and beta diversity (species diversity across samples) and conducted a taxonomic analysis. We also looked for the presence of potentially pathogenic species. Major differences were found in the microbiome composition and relative abundances depending on the water source. A lower alpha diversity was observed in the cistern sample compared to the others, and distinct differences in the microbiome composition and relative abundance were noted between the samples. Notably, pathogenic species, or genera known to harbor such species, were detected in all the samples. We conclude that DNA metabarcoding can provide an effective and comprehensive assessment of drinking water quality and has the potential to identify pathogenic species overlooked using traditional methods. This method also shows promise for tracing the source of disease outbreaks due to waterborne microorganisms. This is the first study from small island countries in the Caribbean where metabarcoding has been applied for assessing freshwater water quality.
ABSTRACT
INTRODUCTION: Acinetobacter baumannii is an emerging multi-drug resistant opportunistic pathogen that causes a variety of nosocomial infections. In recent years, carbapenem resistance in A.baumannii has increased due to Ambler class B Metallo ß-lactamases or class D OXA Carbapenemases. OBJECTIVE: The present study was undertaken to detect and compare the various phenotypic methods for MBL production in nosocomial A.baumannii isolates. MATERIALS AND METHODS: One hundred sixty eight A.baumannii isolates were subjected to disc diffusion assay. Imipenem resistant isolates were subjected to 4 different phenotypic tests. MBL screening was done by Imipenem-EDTA double disc synergy test, Imipenem-EDTA combined disc test, Modified Hodge test and MBL E-test. RESULTS: Out of 168 A.baumannii isolates, 85 (50.59%) were imipenem resistant. Among these 85 isolates, 57 (67.05%) were MBL positive by DDST, 69 (81.18%) by CDT, 85 (100%) by MHT and all these 85 isolates were confirmed to be MBL positive by MBL E-test method. CONCLUSION: Combined disc test, Modified Hodge test & E-test are equally effective to detect MBL production. However, considering the cost constraints of E-test, simple MHT and CDT can be used. They are easy, economical and can be incorporated into routine testing in laboratories to monitor the emergence of MBLs in MDR A.baumannii.
ABSTRACT
Perforations of nasal septum are fairly frequent with an incidence of about 0.9 % and may lead to morbidity than mortality. Common causes are trauma (iatrogenic occasionally nose picking), malignancy, inflammations and infections such as tuberculosis, syphilis, Wegener's granulomatosis, sarcoidosis and fungal infections. Paranasal fungal sinusitis is frequently encountered in clinical practice in both immunocompromised and immunocompetent individuals. Nasal septal perforations caused by species of Aspergillus and Fusarium have been documented. We report a case of nasal septal perforation in a 35-years-old immunocompetent male patient due to Purpureocillium lilacinum, a soil and environmental fungus and an emerging pathogen, which is known to cause various infections in humans with normal and deficient immune system. Fungal aetiology was diagnosed by histopathology and direct smear examination and confirmed by culture. Patient was treated with voriconozole, following Antifungal susceptibility testing (AFST), to which the patient is responding.
