Spectrum of Bacterial Pathogens in Critical COVID-19 Patients Admitted in Intensive Care Units of a Tertiary Care Hospital During the First and Second Wave of the Pandemic

Objective: This study intends to compare the clinical characteristics and the prevalence and spectrum of bacterial pathogens in COVID-19 patients admitted to ICU during the first and second waves at a tertiary care, teaching and referral hospital of eastern India. Method: This is a hospital-based retrospective study which analysed demographic details, clinical profile and bacterial culture results of severe and critically ill COVID-19 patients admitted in intensive care units (ICU) during April -Oct 2020 (1 st wave) and April –July 2021 (2 nd wave). Result: The patients admitted during the 2 nd wave were comparatively older and had multiple comorbidities compared to the 1 st wave. (23.8%) (45/189) and 50% (173/346) of the COVID-19 patients admitted to ICU developed bacterial infection during the 1 st and 2 nd wave respectively. Overall, there was predominance of multidrug resistant Gram negative bacilli in both the waves. There was increased isolation of intrinsic colistin resistant microorganisms. Conclusion: Multidrug resistant Gram negative bacterial infections, remain a dreaded complication in severe and critically ill hospitalised COVID-19 patients requiring ICU care and high usage of colistin spirals the emergence and spread of pathogens intrinsically resistant to colistin.

Antibiotic susceptibilities, streptococcal pyrogenic exotoxin gene profiles among clinical isolates of group C or G Streptococcus dysgalactiae subsp. equisimilis & of group G S. anginosus group at a tertiary care centre.

Background & objectives: Group C and group G streptococci (together GCGS) are often regarded as commensal bacteria and their role in streptococcal disease burden is under-recognized. While reports of recovery of GCGS from normally sterile body sites are increasing, their resistance to macrolides, fluoroquinolone further warrants all invasive β haemolytic streptococci to be identified to the species level and accurately tested for antimicrobial susceptibility. This study was aimed to determine the prevalence, clinical profile, antimicrobial susceptibility and streptococcal pyrogenic exotoxin gene profile (speA, speB, speC, speF, smeZ, speI, speM, speG, speH and ssa) of GCGS obtained over a period of two years at a tertiary care centre from north India. Methods: The clinical samples were processed as per standard microbiological techniques. β-haemolytic streptococci (BHS) were characterized and grouped. Antimicrobial susceptibility of GCGS was performed using disk diffusion method. All GCGS were characterized for the presence of streptococcal pyrogenic exotoxins (spe) and spe genes were amplified by PCR method. Results: GCGS (23 GGS, 2GCS) comprised 16 per cent of β haemolytic streptococci (25/142 βHS, 16%) isolated over the study period. Of the 25 GCGS, 22 (88%) were recovered from pus, two (8%) from respiratory tract, whereas one isolate was recovered from blood of a fatal case of septicaemia. Of the total 23 GGS isolates, 18 (78%) were identified as Streptococcus dysgalactiae subsp equisimilis (SDSE, large-colony phenotype), five (21%) were Streptococcus anginosus group (SAG, small-colony phenotype). The two GCS were identified as SDSE. All GCGS isolates were susceptible to penicillin, vancomycin, and linezolid. Tetracycline resistance was noted in 50 per cent of SDSE isolates. The rates of macrolide and fluoroquinolone resistance in SDSE were low. Twelve of the 20 SDSE isolates were positive for one or more spe genes, with five of the SDSE isolates simultaneously carrying speA+ speB+ smeZ+ speF or speB+ smeZ+speF, speI+speM+speG+speH or, speI+spe M+speH or speA+ speB+ speC+ smeZ+ speF. One notable finding was the presence of spe B in four of the five isolates of the Streptococcus anginosus group. No isolate was positive for ssa. Interpretation & conclusions: Our study showed no association between GCGS isolates harbouring streptococcal pyrogenic exotoxins and disease severity. This might be attributed to the small sample size of spe-positive isolates.

Salmonella enterica enteritidis arthritis following trauma in a child with thalassemia major.

Osteoarticular infections caused by Non-typhi Salmonella are exceptionally encountered. We report a case of a bacteriologically documented knee joint infection due to Salmonella enterica serotype enteritidis, following trauma in a child with thalassemia major. Emergency arthrotomy combined with antimicrobial therapy was helpful in eradication of infection. Physicians should be aware of this rare manifestation of Non-typhi Salmonella infections in thalassemic patients.

Tigecycline susceptibility report from an Indian tertiary care hospital.

Background & objectives: Treatment of serious life threatening infections due to multi-drug resistant pathogens presents a difficult challenge due to the limited therapeutic options. Therefore, we studied the in vitro susceptibility of tigecycline, a new glycylcycline with promising broad spectrum of activity against Gram positive and Gram negative bacteria at a tertiary care hospital in north India. Methods: A total of 75 multi-drug resistant isolates of methicillin resistant Staphylococcus aureus (21), vancomycin resistant enterococci (14), vancomycin resistant Streptococcus spp. (3), extended spectrum β lactamase producing Gram negative bacteria (11) and multi-resistant Acinetobacter spp. (26) were tested for tigecycline susceptibility by the E- test and disc diffusion methods. An additional 83 multi-resistant Gram negative clinical isolates were screened by disc diffusion method alone. Results: All the isolates of MRSA, VRE, vancomycin resistant Streptococcus spp. and ESBL producing enteric bacteria were sensitive to tigecycline by the E-test and disc diffusion methods. However, only 42 per cent of Acinetobacter spp. were found to be sensitive to tigecycline by the E-test method. Interpretation & conclusions: In conclusion, tigecycline was found to be highly effective against Gram- positive bacteria and Gram-negative members of Enterobacteriaceae, but a high prevalence of resistance in members of Acinetobacter spp. is worrisome.