Circulating serotypes and genotypes of dengue virus in North India: An observational study.

BACKGROUND OBJECTIVES: This study reports observation on circulating serotypes and genotypes of Dengue Virus in North India. METHODS: Serum samples were obtained from suspected cases of dengue referred to the virus diagnostic laboratory during 2014 to 2022. All samples were tested for anti-dengue virus IgM antibodies and NS1Ag by ELISA. NS1Ag positive samples were processed for serotyping and genotyping. RESULTS: Total 41,476 dengue suspected cases were referred to the laboratory of which 12,292 (29.6%) tested positive. Anti-Dengue Virus IgM antibodies, NS1Ag, both IgM and NS1Ag, were positive in 7007 (57.4%); 3200 (26.0%) and 2085 (16.0%) cases respectively. Total 762 strains were serotyped during 9-year period. DENV-1, DENV-2, DENV-3 and DENV-4 serotypes were found in 79 (10.37%), 506 (66.40%), 151 (19.82%) and 26 (3.41%) cases respectively. DENV-1, DENV-2 and DENV-3 were in circulation throughout. Total 105 strains were genotyped. Genotype IV of DENV-1 serotype was circulating till 2014 which was later replaced by genotype V. A distinct seasonality with increase in number of cases in post-monsoon period was seen. INTERPRETATION CONCLUSION: DENV-1, DENV-2 and DENV-3 were found to be in circulation in North India. Predominant serotype/genotype changed at times, but not at regular intervals.

Association of Virulence Markers With Resistance to Oral Antibiotics in Escherichia coli Isolates Causing Uncomplicated Community-Acquired Cystitis.

INTRODUCTION: Uropathogenic Escherichia coli (UPEC) strains equipped with putative virulence factors (VFs) are known to cause approximately 90% of lower urinary tract infections (UTIs) or cystitis affecting individuals of all age groups. Only limited laboratory-based data on the correlation of antimicrobial resistant patterns and VFs of UPEC are available. MATERIALS AND METHODS: A total of 100 non-duplicate E. coli isolates associated with community-acquired UTIs in sexually active women were analysed for antimicrobial susceptibility patterns and putative virulence-associated genes. Antimicrobial susceptibility testing (AST) was carried out by the Kirby-Bauer disk diffusion method, and results were interpreted as per Clinical and Laboratory Standards Institute (CLSI) guidelines. The isolates non-susceptible to ≥1 agent in ≥3 different antimicrobial categories were considered multidrug-resistant (MDR). Multiplex polymerase chain reaction assay was performed on each E. coli isolate to characterize putative virulence genes (VGs) such as papA, malX, PAI, ibeA, fimH, fyuA, sfa/focDE, papGIII, iutA, papGI, kpsMTII, hlyA, papGII, traT, afa/draBC, cnf1, vat, and yfcV. Results: Capsule synthesis gene kpsMTII (59%)was the most predominant VG present, followed by serum resistance-associated transfer protein gene traT (58%) and adhesin gene fimH (57%); however, adhesin gene papGI (2%) was the least present. The prevalence of antimicrobial resistance was relatively high for commonly used oral antimicrobials of UTI treatment, such as trimethoprim-sulfamethoxazole (68%) and fluoroquinolones (63%). The majority of isolates were MDR (78%) and resistant to extended-spectrum cephalosporins (63.5%). Isolates resistant to norfloxacin and trimethoprim-sulfamethoxazole were also resistant to almost all available oral antimicrobials. Isolates resistant to extended-spectrum cephalosporins showed increased resistance to aztreonam and trimethoprim-sulfamethoxazole (84.6% each) and fluoroquinolones (ciprofloxacin and norfloxacin; 81.5% each). Fosfomycin and nitrofurantoin were the most sensitive antimicrobials for all these resistant isolates. In a multivariate analysis, it was found that MDR isolates were associated with many of the VGs; fimH (65.4%) being the most frequent followed by traT (64.1%). traT (66.2%) and iutA (60.3%) were most commonly present in E. coli isolates resistant to trimethoprim-sulfamethoxazole, while66.7% norfloxacin-resistant isolates have them. Isolates resistant to extended-spectrum cephalosporins were most commonly associated with fimH and traT (66.2% each). However, E. coli isolates positive for sfa/focDE and vat were more sensitive to norfloxacin and trimethoprim-sulfamethoxazole and were non-MDR strains predominantly (p < 0.05). Only two VGs (fimH and traT) were significantly associated with MDR strains. DISCUSSION: The results of the present study clearly show the association of VFs with some of the commonly used oral antibiotics emphasizing the need for further molecular studies and surveillance programs to monitor drug-resistant UPEC so as to form optimized diagnostic stewardship and appropriate regimen for patient treatment. The reason behind this phenomenon of association has not been studied in much detail here but it can be assumed that genes responsible for drug resistance may share neighbouring loci with VGs on the mobile genetic elements (e.g., plasmid), which transfer together from one bacterium to another.

Virulence Genotyping and Multidrug Resistance Pattern of Escherichia coli Isolated From Community-Acquired and Hospital-Acquired Urinary Tract Infections.

Introduction Uropathogenic Escherichia coli(UPEC) strains consist of a plethora of putative virulence factors (VFs), which help them to establish infection in the urinary tract. We compared genotypic profiles of Escherichia coli (E. coli) strains associated with community-acquired (CA) urinary tract infection (UTI; n=100) and hospital-acquired (HA) UTI (n=50) in the present study in order to identify specific virulence determinants, if any, associated with either form of UTI and its association with antibiotic resistance pattern of the isolates. Materials and methods E. coli strains were analyzed for antimicrobial susceptibility patterns, phylogroups, and 10 putative virulence-associated genes. The bacterial culture and identification were done using standard conventional methods. Tests for antimicrobial susceptibility and phenotypic detection for extende- spectrum beta-lactamases (ESBL) were done by using the Kirby Bauer disc diffusion method, and results were interpreted as per Clinical & Laboratory Standards Institute (CLSI) guidelines. The phylotype (A, B1, B2, and D) of each E. coli isolate was determined by a triplex polymerase chain reaction (PCR) based phylotyping method. They were further analyzed for the presence of 10 putative virulence genes (VGs), including adhesins papA (P fimbrial structural subunit), papG alleles I, II (P fimbrial adhesin variants), fimH (type 1 fimbriae), toxins hlyA (hemolysin) siderophores chuA (heme-binding protein); yfcV (encodes a major subunit of a putative chaperone-usher fimbria) capsule synthesis specific for group II (K1, K5, K12, etc.) kpsMII; serum resistance-associated traT, and upaH by multiplex PCR. Results HA E. coli isolates were significantly more drug-resistant than CA isolates; carbapenem (80% vs. 16%), ceftazidime (92% vs. 63%). The majority (52%) of E.coli isolates associated with HA UTI belong to commensal phylogroup A and B1, whereas the majority (66%) in CA were from pathotypic phylogroups, i.e., B2 & D. Most of VFs were frequently present amongst CA group except for traT and yfc, kpsMTII, hlyA, chuA, and upaH were significantly associated with CA E.coli isolates while yfc was significantly present in HA E.coli isolates. Though adhesin genes such as papA, papGI, papGII, fimH were frequently found in the CA group, they were not significantly associated. The average virulence score was higher for CA UTI isolates (4.25) than for the HA strains (3.9). Multidrug resistance (MDR) was present in every HA E.coli isolate, and fimH, traT, and yfc genes showed significant association with MDR strains. Conclusion On detailed analysis, we found that HA E. coli isolates had a high frequency of MDR and comparatively reduced VFs content. Thus, it can be assumed that a strain with lesser virulence is able to cause HA UTIs, as compared to CA UTIs, which probably indicates that the host's immune status/general condition can be an important determinant in acquiring infection rather than virulence potential of the pathogen alone.

Chryseobacterium Indologenes-Associated Pneumonia in 2 Neonates.

Chryseobacterium species are widely distributed in nature and can rarely cause human infection. Few cases reported in hospitalized patients are in immunocompromised hosts with indwelling devices and associated comorbidities. Chryseobacterium species are usually multidrug resistant. We describe 2 cases of Chryseobacterium indologenes-associated pneumonia in neonates and review the published infant cases.