Antibiotic Susceptibility Pattern of Aerobic Bacterial Pathogen Isolated from Endotracheal Aspirate.

BACKGROUND: Ventilator-associated pneumonia (VAP) is one of the major hospital-acquired infections and the emergence of bacterial resistance is common among patients in the intensive care units (ICUs). The aim of the study is to identify the common bacterial pathogen isolated from an endotracheal (ET) aspirate and its antibiotic susceptibility pattern. MATERIALS AND METHODS: A prospective analytical study was carried out in a tertiary care hospital for a period of 1 year. All ET aspirate sample sent to the microbiology laboratory was processed and identified by standard biochemical tests and antibiotic sensitivity was by disk diffusion method as per Clinical and Laboratory Standards Institute (CLSI) guidelines. RESULTS: Of the total 217 samples studied, 85 (39.17.1%) were culture sterile and 132 (60.82%) showed culture positive. Among 132 isolates, the predominant organism was Acinetobacter baumannii (36.36%) followed by Klebsiella pneumoniae (24.24%) and Pseudomonas aeruginosa (20.45%). We have reported a higher percentage of resistance among the isolated gram-negative bacilli to carbapenems, aminoglycosides, and third-generation cephalosporins, with increased sensitivity to piperacillin-tazobactam and cefoperazone-sulbactam. CONCLUSION: In our study, A. baumannii was the predominantly isolated gram-negative bacilli followed by K. pneumoniae and P. aeruginosa. One of the rising concerns to hospital-acquired respiratory pathogens is the surge of multidrug resistance patterns. Hence, strict adherence to antibiotic policy and appropriate use according to the guidelines will save the use of drugs in the future in life-threatening conditions.

Insights from Genomes and Genetic Epidemiology of SARS-CoV-2 isolates from the state of Andhra Pradesh

Coronavirus disease (COVID-19) emerged from a city in China and has now spread as a global pandemic affecting millions of individuals. The causative agent, SARS-CoV-2 is being extensively studied in terms of its genetic epidemiology using genomic approaches. Andhra Pradesh is one of the major states of India with the third-largest number of COVID-19 cases with limited understanding of its genetic epidemiology. In this study, we have sequenced 293 SARS-CoV-2 genome isolates from Andhra Pradesh with a mean coverage of 13,324X. We identified 564 high-quality SARS-CoV-2 variants, out of which 15 are novel. A total of 18 variants mapped to RT-PCR primer/probe sites, and 4 variants are known to be associated with an increase in infectivity. Phylogenetic analysis of the genomes revealed the circulating SARS-CoV-2 in Andhra Pradesh majorly clustered under the clade A2a (94%), while 6% fall under the I/A3i clade, a clade previously defined to be present in large numbers in India. To the best of our knowledge, this is the most comprehensive genetic epidemiological analysis performed for the state of Andhra Pradesh.

Odontogenic keratocyst arising in the maxillary sinus: A rare case report.

Odontogenic keratocyst is an aggressive cystic lesion and a common type of tooth derived cyst due to presence of odontogenic epithelial remnants in different regions of jaw. In majority of cases, it is located in mandibular posterior region. But it can also be found in the maxilla especially in the canine region. We present a rare case of OKC in maxillary sinus which associated with ectopic third molar. Also, it can be easily confused with other lesions of maxillary sinus like sinusitis or antral polyps, which usually resemble symptomatically. There can be malignant transformation of this benign condition towards squamous cell carcinoma or ameloblastoma. So an early and accurate diagnosis of odontogenic keratocyst is a challenge for pathologists.

A type IV secretion system contributes to intracellular survival and replication of Burkholderia cenocepacia.

Burkholderia cenocepacia is an important respiratory pathogen in persons with cystic fibrosis (CF). Recent studies indicate that B. cenocepacia survives within macrophages and airway epithelial cells in vitro by evading endosome-lysosome fusion. We investigated the role of a plasmid-encoded type IV secretion system in the intracellular survival, replication, and processing of B. cenocepacia. Both a wild-type strain (K56-2) and its type IV secretion system mutant (designated LC101) entered and replicated in CF airway epithelial cells and monocyte-derived macrophages. However, significantly more intracellular K56-2 than LC101 bacteria were found in both cell types at 24 h postinfection. Colocalization of bacteria with markers of the classical endocytic pathway indicated that although both K56-2 and LC101 reside transiently in early endosomes, a greater proportion of the mutant bacteria are targeted to lysosomal degradation. In contrast, wild-type bacteria escape from the classical endocytic pathway and traffic to the endoplasmic reticulum, where they replicate. Our results show that the intracellular processing of B. cenocepacia is similar in both professional and nonprofessional phagocytes and that a functional plasmid-encoded type IV secretion system contributes to the survival and replication of B. cenocepacia in eukaryotic cells.

Effect of chondroitinase ABC on purulent sputum from cystic fibrosis and other patients.

Cystic fibrosis (CF) patients develop chronic lung infections associated with airway obstruction by viscous and insoluble mucus secretions. Although mucus glycoproteins (mucins) are thought to be responsible for mucus plugs, other glycoconjugate components of airway secretions have not been systematically evaluated. The aim of the present study was to determine whether chondroitin sulfate proteoglycans (CSPG) contribute to the insolubility of CF sputum. Sputa obtained from 18 CF patients were incubated with chondroitinase ABC (ChABC) or buffer (control) for 18 h at 37 degrees C, and after centrifugation at 12,000 g, the volume of the insoluble pellet and turbidity of the supernatant were determined as measures of solubility. ChABC caused a 70-90% reduction in supernatant turbidity and a 60-70% decrease in pellet volume of the 13 purulent CF sputa, but had much less effect on the five nonpurulent CF sputa tested. Similar results were obtained with two non-CF purulent and two non-CF, nonpurulent sputa. Gel electrophoresis, Western blot, and slot blot immunoassays with antichondroitin sulfate and antimucin antibodies revealed that purulent sputa (CF and non-CF) contained more CSPG and less mucin than nonpurulent sputa. In vitro mixing experiments showed that mucin in nonpurulent sputa was reduced upon incubation with purulent sputa, presumably because of degradation or a loss of immunoreactive mucin epitopes from leukocyte and/or bacterial enzymes present in purulent sputa. Our results suggest that CSPG contribute more significantly than mucins to the insolubility of purulent tracheobronchial secretions from CF patients. Because purulent sputa from non-CF patients showed a similar pattern, our observations with CF sputa may have wider applicability.