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Chryseobacterium indologenes is found ubiquitously in the environment; it rarely causes human disease. Hence, we report a case of C. indologenes-associated pleural effusion in a patient with aortic dissection. Postoperatively, the patient developed massive right-sided pleural effusion with underlying consolidated lung. Culture of the pleural fluid yielded pure growth of C. indologenes which was susceptible to cotrimoxazole, minocycline, and tigecycline. Therapy was modified; tigecycline and cotrimoxazole were started following which the patient showed improvement, and subsequent cultures of the pleural fluid were sterile. This report promotes awareness of this organism as an emerging pathogen in lung infections and emphasizes the importance of targeted therapy.

Background Despite being in the 5th month of pandemic, knowledge with respect to viral dynamics, infectivity and RT-PCR positivity continues to evolve. Aim To analyse the SARS CoV-2 nucleic acid RT-PCR profiles in COVID-19 patients. Design It was a retrospective, observational study conducted at COVID facilities under AIIMS, New Delhi. Methods Patients admitted with laboratory confirmed COVID-19 were eligible for enrolment. Patients with incomplete details, or only single PCR tests were excluded. Data regarding demographic details, comorbidities, treatment received and results of SARS-CoV-2 RT-PCR performed on nasopharyngeal and oropharyngeal swabs, collected at different time points, was retrieved from the hospital records. Results 298 patients were included, majority were males (75·8%) with mean age of 39·07 years (0·6–88 years). The mean duration from symptom onset to first positive RT-PCR was 4·7 days (SD 3·67), while that of symptom onset to last positive test was 17·83 days (SD 6·22). Proportions of positive RT-PCR tests were 100%, 49%, 24%, 8·7% and 20·6% in the 1st, 2nd, 3rd, 4th & >4 weeks of illness. 12 symptomatic patients had prolonged positive test results even after 3 weeks of symptom onset. Age > = 60 years was associated with prolonged RT-PCR positivity (statistically significant). Conclusion This study showed that the average period of PCR positivity is more than 2 weeks in COVID-19 patients; elderly patients have prolonged duration of RT-PCR positivity and requires further follow up.

Introduction: Increasing occurrence of infections caused by multidrug-resistant Gram-negative bacteria resulted in colistin being the last agent for treatment. Apart from plasmid-mediated mcr genes, mutations involving several genes like mgrB, phoP/phoQ, pmrA, pmrB, pmrC, and crrABC genes, are leading causes of colistin resistance. Four colistin susceptibility testing methods were compared against broth microdilution (BMD) and determined the presence of the mcr1-5 gene. Methodology: A total of 100 carbapenem-resistant Enterobacterales isolates were tested for colistin susceptibility by commercial broth microdilution (cBMD), E-test, VITEK-2, and rapid polymyxin NP assay (RPNP) and compared with BMD. The presence of the mcr1-5 gene was determined by modified RPNP and PCR. Two non- mcr colistin-resistant XDR isolates were subjected to whole-genome sequencing using Illumina MiSeq sequencing platform. Results: Among 100 carbapenem-resistant Enterobacterales isolates, 15% were resistant to colistin. Essential agreement, categorical agreement, major error, and very major error for cBMD/E-test/VITEK-2/RPNP were 96%/73%/82%/NA; 99%/86%/88%/91%, 1.2%/9.4%/11.8%/8.2% and 0%/40%/13.3%/13.3%, respectively. Only one Klebsiella pneumoniae isolate harbored the mcr-1 gene, observed by both methods. Whole-genome sequencing of two non- mcr XDR Klebsiella pneumoniae showed multiple mutations in 10 genes responsible for lipopolysaccharide biosynthesis. Conclusions: The performance of cBMD was excellent, whereas the E-test was unacceptable. VITEK-2 and RPNP performed better but remained unreliable due to high error rates. Multiple mutations in the target proteins involving lipopolysaccharide formation, modification, and regulation were seen, resulting in colistin resistance.

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