Antimicrobial Resistance, Virulence Profiles and Molecular Subtypes of Salmonella enterica Serovars Typhi and Paratyphi A Blood Isolates from Kolkata, India during 2009-2013

Abstract

Enteric fever, caused by Salmonella enterica, remains an unresolved public health problem in India and antimicrobial therapy is the main mode of treatment. The objective of this study was to characterize the Salmonella enterica isolates from Kolkata with respect to their antimicrobial resistance (AMR), virulence profiles and molecular subtypes. Salmonella enterica blood isolates were collected from clinically suspected enteric fever patients attending various hospitals in Kolkata, India from January 2009 to June 2013 and were tested for AMR profiles by standard protocols; for resistance gene transfer by conjugation; for resistance and virulence genes profiles by PCR; and for molecular subtypes by Pulsed Field Gel Electrophoresis (PFGE). A total of 77 Salmonella enterica serovar Typhi (S. Typhi) and 25 Salmonella enterica serovar Paratyphi A (S. Paratyphi A) from Kolkata were included in this study. Although multidrug resistance (resistance to chloramphenicol, ampicillin, co-trimoxazole) was decreasing in S. Typhi (18.2%) and absent in S. Paratyphi A, increased resistance to fluoroquinolone, the current drug of choice, caused growing concern for typhoid treatment. A single, non-conjugative non-IncHI1 plasmid of 180 kb was found in 71.4% multidrug resistant (MDR) S. Typhi; the remaining 28.6% isolates were without plasmid. Various AMR markers (bla TEM-1, catA, sul1, sul2, dfrA15, strA-strB) and class 1 integron with dfrA7 gene were detected in MDR S. Typhi by PCR and sequencing. Most of the study isolates were likely to be virulent due to the presence of virulence markers. Major diversity was not noticed among S. Typhi and S. Paratyphi A from Kolkata by PFGE. The observed association between AMR profiles and S. Typhi pulsotypes might be useful in controlling the spread of the organism by appropriate intervention. The study reiterated the importance of continuous monitoring of AMR and molecular subtypes of Salmonella isolates from endemic regions for better understanding of the disease epidemiology.

First case report of blood and urine cultures positive bacteraemia by Salmonella enterica serotype Choleraesuis from India

“…Following sample collection, the patient was immediately given empirical treatment with parenteral ceftriaxone (2 g twice daily) in anticipation that the patient was suffering from typhoid fever; most of the recent S. Typhi Kolkata isolates had shown decreased susceptibility to ciprofloxacin (Dutta et al, 2014). When the culture-susceptibility results became available, the clinician added ciprofloxacin (200 mg twice daily) for 10 days to prevent relapse, which is common with S. Choleraesuis infection .…”

ANTIMICROBIAL RESISTANCE OF Salmonella enterica serovars typhi and paratyphi FROM BLOOD ISOLATES IN CHILDREN FROM A NORTH DELHI TERTIARY CARE HOSPITAL

“…Infection in children is reportedly more as compared to elderly [2][3][4]. Mainstay of enteric fever treatment includes fluoroquinolones, third generation cephalosporin and azithromycin [2][3][4][5][6][7]. Emergence of antimicrobial resistance was reported for Salmonella isolates from 1960 onwards including multi drug resistance [5].…”

“…MDR Salmonella strains are more virulent in terms of morbidity and mortality, a troublesome fact concerning clinical management and prevention of these infections [1]. In India, first multi drug resistant Salmonella typhi (MDRST) outbreak was reported in 1960 from Calicut [6]. Increasing multi drug resistant isolates were being reported since then from all over the world.…”

“…Increasing multi drug resistant isolates were being reported since then from all over the world. MDR incidence has been reported as high as 80 % during 1980 to 2004 from various parts of India [6]. A variable declining trend was observed thereafter from India and other countries [9][10][11].…”

Distribution and Antimicrobial Resistance of Salmonella Serovars Isolated in Kayseri Region

“…Son yıllarda tüm dünyada Salmonella izolatlarındaki antimikrobiyal direnç oranlarının artığı bildirilmektedir (7,8). Ampisilin, kloramfenikol, trimetoprimsülfametoksazol gibi geleneksel birinci basamak ilaçların yanı sıra, seftriakson ve florokinolonlara da direnç bildirilmiştir (9)(10)(11)(12). Antibiyotik direncinin giderek artması, antibiyotik kullanımının gerekli olduğu durumlarda, ampirik tedavi seçenek-lerini etkilemesi bakımından oldukça önemlidir.…”