Characterization of Transferrable Mechanisms of Quinolone Resistance (TMQR) among Quinolone-resistant Escherichia coli and Klebsiella pneumoniae causing Urinary Tract Infection in Nepalese Children.

BACKGROUND: Transferrable mechanisms of quinolone resistance (TMQR) can lead to fluoroquinolone non-susceptibility in addition to chromosomal mechanisms. Some evidence suggests that fluoroquinolone resistance is increasing among the pediatric population. We sought to determine the occurrence of TMQR genes among quinolone-resistant E. coli and K. pneumoniae causing urinary tract infections among Nepalese outpatient children (< 18 years) and identify molecular characteristics of TMQR-harboring isolates. METHODS: We performed antimicrobial susceptibility testing, phenotypic extended-spectrum ß-lactamase (ESBL) and modified carbapenem inactivation method tests, and investigated the presence of six TMQR genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr, oqxAB, qepA), three ESBL genes (blaCTX-M, blaTEM, blaSHV), and five carbapenemase genes (blaNDM, blaOXA-48, blaKPC, blaIMP, blaVIM). The quinolone resistance-determining region (QRDR) of gyrA and parC were sequenced for 35 TMQR-positive isolates. RESULTS: A total of 74/147 (50.3%) isolates were TMQR positive by multiplex PCR [aac(6')-Ib-cr in 48 (32.7%), qnrB in 23 (15.7%), qnrS in 18 (12.3%), qnrA in 1 (0.7%), and oqxAB in 1 (0.7%) isolate]. The median ciprofloxacin minimum inhibitory concentration of TMQR-positive isolates (64 µg/mL) was two-fold higher than those without TMQR (32 µg/mL) (p = 0.004). Ser-83→Leu and Asp-87→Asn in GyrA and Ser-80→Ile in ParC were the most common QRDR mutations (23 of 35). In addition, there was a statistically significant association between TMQR and two ß-lactamase genes; blaCTX-M (p = 0.037) and blaTEM (p = 0.000). CONCLUSION: This study suggests a high prevalence of TMQR among the quinolone-resistant E. coli and K. pneumoniae isolates causing urinary tract infection in children in this area of Nepal and an association with the carriage of ESBL gene. This is a challenge for the management of urinary infections in children. Comprehensive prospective surveillance of antimicrobial resistance in these common pathogens will be necessary to devise strategies to mitigate the emergence of further resistance.

Liver metastases - An unusual cause of portal hypertension: A case report.

Introduction: Portal hypertension is a rare complication of liver metastases. The study highlights that clinician should be aware of conditions mimicking cirrhosis with similar clinical presentation and imaging findings. Case presentation: We present the case of a 29-year-old non-alcoholic lady who presented to our hospital with a history of two months of progressive, painless abdominal distension and progressively increasing yellowish discoloration of the eyes. Physical examination, laboratory investigations, and imaging tests led to a diagnosis of multiple metastases from breast carcinoma to the liver leading to portal hypertension after exclusion of other causes of portal hypertension. However, after three weeks of presentation to the hospital, the patient died before any therapeutic measures were initiated to address breast carcinoma. Clinical discussion: Liver metastasis from primary breast carcinoma rarely presents with clinical symptoms of portal hypertension. Although portal hypertension secondary to pseudocirrhosis, predominantly linked to ongoing chemotherapy for known cancers, has been previously described in case studies, our case had an unusual presentation leading to diagnostic uncertainty. Conclusion: Our case highlights the rare cause of liver metastasis secondary to breast carcinoma, which presented as portal hypertension.