Evolutionary trends of carbapenem-resistant and susceptible Acinetobacter baumannii isolates in a major tertiary care setting from North India.

Emergence of carbapenem-resistant A. baumannii (CRAB) is a global, ongoing healthcare concern. CRAB is among the topmost priority pathogens, with various studies focusing on its global population structure and resistant allelic profiles. However, carbapenem-susceptible A. baumannii (CSAB) isolates are often overlooked due to their sensitivity to beta-lactams, which can provide important insights into origin of CRAB lineages and isolates. In the present study, we report genomic investigation of CRAB and CSAB coexisting in Indian hospital setting. MLST based population structure and phylogenomics suggest they mainly follow distinct evolutionary routes forming two phylogroups. PG-I exclusively for a successful clone (ST2) of CRAB and PG-II comprises diversified CSAB isolates except PG3373, which is CRAB. Additionally, there are few CRAB isolates not belonging to PG-I and sharing clonal relationship with CSAB isolates indicating role of genome plasticity towards extensive drug resistance in the nosocomial environment. Further, genealogical analysis depicts prominent role of recombination in emergence and evolution of a major CRAB lineage. Further, CRAB isolates are enriched in resistomes as compared to CSAB isolates, which were encoded on the genomic island. Such comparative genomic insights will aid in our understanding and localized management of rapidly evolving pandrug resistant nosocomial pathogens.

Susceptibility of clinical isolates of novel pathogen Stenotrophomonas sepilia to novel benzoquinolizine fluoroquinolone levonadifloxacin.

Background: Stenotrophomonas sepilia, identified in 2021, is part of the Stenotrophomonas maltophilia complex (Smc) and shares high genomic identity with S. maltophilia. Resistance to levofloxacin, the recommended fluoroquinolone for S. maltophilia, is being increasingly reported. Recent studies indicate that levonadifloxacin, a novel benzoquinolizine, may be more effective. This study evaluates the antimicrobial efficacy of levofloxacin and levonadifloxacin against clinical isolates of S. sepilia. Objectives: To assess the antibacterial effectiveness of levofloxacin and levonadifloxacin against novel pathogen S. sepilia. Methods: A total of 116 S. maltophilia isolates, identified by MALDI-TOF MS, were collected from five centres across India. S. sepilia was confirmed by PCR using primers targeting a unique genomic sequence (NCBI accession number LXXZ00000000.1). Minimum inhibitory concentrations (MICs) of levonadifloxacin and levofloxacin were determined by using the microbroth-dilution method and Etest as per CLSI guidelines. The levofloxacin breakpoint was used to interpret MICs of levonadifloxacin. Results: Among a total of 116 circulating S. maltophilia isolates collected, 46 were identified as S. sepilia, representing a prevalence rate of (∼40%), thus highlighting its significance as an important pathogen within the Smc. Both levofloxacin and levonadifloxacin demonstrated a 98% inhibition rate against the 46 S. sepilia tested. Only one S. sepilia isolate resistant to levofloxacin showed intermediate susceptibility to levonadifloxacin, which consistently had lower MICs. Conclusions: Levofloxacin and levonadifloxacin show similar susceptibility rates against S. sepilia, with levonadifloxacin exhibiting lower MICs. Further studies are required to establish clinical utility of levonadifloxacin in managing these infections.

Papel da mudança nos níveis de marcadores inflamatórios pós drenagem na previsão de resultado em colangite aguda / Role of change in the levels of inflammatory markers post drainage in predicting outcome in acute cholangitis

ABSTRACT Background: Acute cholangitis (AC) is a gastro-intestinal emergency associated with significant mortality. Role of change in the levels of inflammatory markers post drainage in predicting outcome in acute cholangitis is uncertain. Objective: To evaluate the predictive value of changes in C-reactive protein (CRP) and procalcitonin levels after biliary drainage in relation to outcomes (survival or mortality) at 1 month. Methods A prospective observational study of consecutive adults presenting with AC was performed. At admission and at 48 hours post biliary drainage, procalcitonin and CRP were sent. Results: Between August 2020 till December 2020 we recruited 72 consecutive patients of AC. The median age of the patients was 55 years (range 43-62 years) and 42 (58.33%) were females. Although the delta change in serum procalcitonin (P value<0.001) and CRP (P value<0.001) was significant, it had no bearing on the outcome. Altered sensorium and INR were independently associated with mortality at 1 month. The 30-day mortality prediction of day 0 procalcitonin was measured by receiver operating characteristic analysis which resulted in an area under the curve of 0.697 with a 95% confidence interval (95%CI) of 0.545-0.849. The optimal cut-off of procalcitonin would be 0.57ng/mL with a sensitivity and specificity of 80% and 60% respectively to predict mortality. Conclusion: Change in serum procalcitonin and CRP levels at 48 hours post drainage although significant, had no impact on the outcome of acute cholangitis.

RESUMO Contexto: A colangite aguda (CA) é uma emergência gastro-intestinal associada à significativa mortalidade. O papel da mudança nos níveis de marcadores inflamatórios pós drenagem na previsão do desfecho em CA é incerto. Objetivo: Avaliar o valor preditivo das alterações nos níveis de proteína reativa C (PCR) e procalcitonina após drenagem biliar em relação aos desfechos (sobrevida ou mortalidade) em um mês. Métodos Realizou-se estudo observacional prospectivo de adultos consecutivos que apresentam CA. Na admissão e após 48 horas de drenagem biliar, foram analisadas a procalcitonina e a PCR. Resultados Entre agosto de 2020 e dezembro de 2020, foram recrutados 72 pacientes consecutivos de CA. A idade mediana dos pacientes foi de 55 anos (faixa de 43 a 62 anos) e 42 (58,33%) do sexo feminino. Embora a variação delta no soro procalcitonina (valor P<0,001) e PCR (valor P<0,001) tenha sido significativa, não houve influência sobre o resultado. Sensório alterado e INR foram independentemente associados à mortalidade em 1 mês. A previsão de mortalidade de 30 dias no dia 0 da procalcitonina foi medida pela análise característica operacional receptora que resultou em uma área sob a curva de 0,697 com intervalo de confiança de 95% (IC95%) de 0,545-0,849. O corte ideal de procalcitonina seria de 0,57ng/mL com sensibilidade e especificidade de 80% e 60% respectivamente para prever a mortalidade. Conclusão: A mudança nos níveis de procalcitonina sérica e PCR em 48 horas após a drenagem, embora significativa, não teve impacto no resultado da colangite aguda.

Sensitivity pattern of Salmonella serotypes in Northern India

BACKGROUND: Enteric fever continues to be a major public health problem, especially in the developing countries of the tropics. We determined the incidence of Salmonella bloodstream infections and their antimicrobial resistance patterns from May to August in the years 1997-2001 in Haryana, a large state of India. The minimum inhibitory concentration (MIC) was also determined for 60 isolates of S. typhi to various commonly used antimicrobial agents. MATERIAL AND METHODS: Blood cultures of 6,956 patients (PUO/septicemia) were processed by standard procedures and the Salmonella spp. isolates were identified with specific antisera and with standard biochemical tests. Antimicrobial susceptibilities were determined by Stokes disc diffusion method. The MIC of 60 randomly isolated strains of S. typhi was determined by agar dilution method using Mueller Hinton Agar medium. RESULTS: Isolation rates of Salmonella spp. increased in 2000 and 2001. Multidrug resistance (MDR) in S. typhi had increased while in S. paratyphi it had decreased markedly. Ninety per cent chloramphenicol sensitivity was seen in S. typhi by MIC method. There was a decrease in the susceptibility to ciprofloxacin of S. typhi with MIC showing an upward trend. All S. typhi tested were sensitive to third generation cephalosporins and aminoglycosides with MIC well below the breakpoint. DISCUSSION: Our study indicates that MDR in S. typhi is on the rise in our area. There is also re-emergence of chloramphenicol sensitivity. Rising MIC values of ciprofloxacin may lead to prolonged treatment, delayed recovery or pose treatment failure. Thus, sensitivity pattern of causative organism must be sought before instituting appropriate therapy to prevent further emergence of drug resistance.