scholarly journals Molecular evaluation of drug resistance in clinical isolates of Salmonella enterica serovar Typhi from Pakistan

2013 ◽  
Vol 7 (12) ◽  
pp. 929-940 ◽  
Author(s):  
Amna Afzal ◽  
Yasra Sarwar ◽  
Aamir Ali ◽  
Abbas Maqbool ◽  
Muhammad Salman ◽  
...  

Introduction: This study aimed to determine the drug susceptibility patterns and genetic elements related to drug resistance in isolates of Salmonella enterica serovar Typhi (S. Typhi) from the Faisalabad region of Pakistan. Methodology: The drug resistance status of 80 isolates were evaluated by determining antimicrobial susceptibility, MICs, drug resistance genes involved, and the presence of integrons. Nalidixic acid resistance and reduced susceptibility to ciprofloxacin were also investigated by mutation screening of the gyrA, gyrB, parC, and parE genes. Results: Forty-seven (58.7%) isolates were multidrug resistant (MDR). Among the different resistance (R) types, the most commonly observed (13/80) was AmChStrTeSxtSmzTmp, which is the most frequent type observed in India and Pakistan. The most common drug resistant genes were blaTEM-1, cat, strA-strB, tetB, sul1, sul2, and dfrA7. Among the detected genes, only dfrA7 was found to be associated in the form of a single gene cassette within the class 1 integrons. Conclusions: MIC determination of currently used drugs revealed fourth-generation gatifloxacin as an effective drug against multidrug-resistant S. Typhi, but its clinical use is controversial. The Ser83→Phe substitution in gyrA was the predominant alteration in nalidixic acid-resistant isolates, exhibiting reduced susceptibility and increased MICs against ciprofloxacin. No mutations in gyrB, parC, or parE were detected in any isolate.

Author(s):  
Dr. Manish Kulshrestha ◽  
Dr. Anjali Kulshrestha

INTRODUCTION: Enteric fever includes typhoid and paratyphoid fever. Peak incidence is seen in children 5–15 years of age; but in regions where the disease is highly endemic, as in India, children younger than 5 years of age may have the highest infection rates. There are about 22 million new typhoid cases occur each year. Young children in poor, resource limited areas, who make up the majority of the new cases and there is a mortality figures of 215,000 deaths annually. A sharp decline in the rates of complications and mortality due to typhoid fever is observed as a result of introduction of effective antibiotic therapy since 1950s. MDR-ST became endemic in many areas of Asia, including India soon after multidrug-resistant strains of Salmonella enterica serotype typhi (MDR-ST) that were resistant to all the three first-line drugs then in use, namely chloramphenicol, amoxycillin and co-trimoxazole emerged in early 1990s. MATERIAL AND METHODS: Only blood culture or bone marrow culture positive cases were included. The patients with culture isolated enteric fever were included in the study. Antimicrobial susceptibility testing was carried out by disk diffusion method using antibiotic discs. The analysis of the antimicrobial susceptibility was carried out as per CLSI interpretative guidelines. RESULTS: A total of 82 culture positive cases were included in the present study. 80 culture isolates were from blood culture and 2 from the bone marrow culture. Salmonella entericasubspecies enterica serovartyphi (S typhi) was isolated from 67 (81.70%) patients while Salmonella enterica subspecies entericaserovarparatyphi (S paratyphi A) was isolated from 13 (15.85%) cases and 2 (2.44%) were Salmonella enterica subspecies entericaserovarschottmuelleri (S paratyphi B). Of the 82 cases 65(79.3%) isolates were resistant to ciprofloxacin, 17 (20.7%) were resistant to nalidixic acid, one (1.2%) case each was resistant to Cefotaxime and ceftriaxone, 2 (2.4%) were resistant to chloramphenicol, 10 (12.2%) were resistant and to cotrimoxazole 3 (3.7%) were resistant. CONCLUSION: In a culture positive cases 65(79.3%) isolates were resistant to ciprofloxacin and 17 (20.7%) were resistant to nalidixic acid. Multidrug resistant isolates were 65(79.3%).


2003 ◽  
Vol 47 (6) ◽  
pp. 2006-2008 ◽  
Author(s):  
Hyunjoo Pai ◽  
Jeong-hum Byeon ◽  
Sunmi Yu ◽  
Bok Kwon Lee ◽  
Shukho Kim

ABSTRACT Six strains of Salmonella enterica serovar Typhi which were resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, streptomycin, tetracycline, and gentamicin were isolated in Korea. This multidrug resistance was transferred by a conjugative plasmid of about 50 kb. The plasmid harbored a class 1 integron, which included six resistance genes, aacA4b, catB8, aadA1, dfrA1, aac(6′)-IIa, and the novel blaP2, in that order. All of the isolates showed the same-size plasmids and the same ribotyping patterns, which suggests a clonal spread of these multidrug-resistant isolates.


2020 ◽  
Vol 48 (10) ◽  
pp. 030006052096229
Author(s):  
Jiachang Liu ◽  
Ruikai Wang ◽  
Ming Fang

Objectives To investigate the clinical and drug resistance characteristics of Providencia stuartii infections in the Huainan region of Anhui and provide a reference for the clinical selection of antimicrobial agents. Methods This single-center retrospective analysis included 76 patients with P. stuartii infection in Huainan during the period from October 2018 to March 2020. The hospital department in which the patients were treated and the drug susceptibility characteristics of the P. stuartii isolates were recorded. Results Among the 76 patients, the lung was the most common site of infection, and intensive care unit was the main hospital department. Extended spectrum beta-lactamase screening revealed expression by all 76 isolates of P. stuartii. Of the 76 isolates, 92.1% exhibited multiple drug resistance or extensive drug resistance. P. stuartii isolates were sensitive to cefepime and imipenem, but not to other beta-lactam antibiotics. Twenty isolates were resistant to all 21 types of antibiotics. Of the 20 patients infected with extensively drug-resistant isolates, nine (45%) died. Conclusions Drug resistance is increasing in P. stuartii. The antimicrobial agent imipenem may be effective for treatment of P. stuartii infections. Fluoroquinolones, aminoglycosides, and fourth-generation cephalosporins are suitable options for antibiotic therapy.


2010 ◽  
Vol 76 (11) ◽  
pp. 3657-3667 ◽  
Author(s):  
Janine Beutlich ◽  
Irene Rodr�guez ◽  
Andreas Schroeter ◽  
Annemarie K�sbohrer ◽  
Reiner Helmuth ◽  
...  

ABSTRACT Recently, Salmonella enterica subsp. enterica serovar Saintpaul has increasingly been observed in several countries, including Germany. However, the pathogenic potential and epidemiology of this serovar are not very well known. This study describes biological attributes of S. Saintpaul isolates obtained from turkeys in Germany based on characterization of their pheno- and genotypic properties. Fifty-five S. Saintpaul isolates from German turkeys and turkey-derived food products isolated from 2000 to 2007 were analyzed by using antimicrobial agent, organic solvent, and disinfectant susceptibility tests, isoelectric focusing, detection of resistance determinants, plasmid profiling, pulsed-field gel electrophoresis (PFGE), and hybridization experiments. These isolates were compared to an outgroup consisting of 24 S. Saintpaul isolates obtained from humans and chickens in Germany and from poultry and poultry products (including turkeys) in Netherlands. A common core resistance pattern was detected for 27 German turkey and turkey product isolates. This pattern included resistance (full or intermediate) to ampicillin, amoxicillin-clavulanic acid, gentamicin, kanamycin, nalidixic acid, streptomycin, spectinomycin, and sulfamethoxazole and intermediate resistance or decreased susceptibility to ciprofloxacin (MIC, 2 or 1 μg/ml, respectively) and several third-generation cephalosporins (including ceftiofur and cefoxitin [MIC, 4 to 2 and 16 to 2 μg/ml, respectively]). These isolates had the same core resistance genotype, with bla TEM-1, aadB, aadA2, sul1, a Ser83→Glu83 mutation in the gyrA gene, and a chromosomal class 1 integron carrying the aadB-aadA2 gene cassette. Their XbaI, BlnI, and combined XbaI-BlnI PFGE patterns revealed levels of genetic similarity of 93, 75, and 90%, respectively. This study revealed that a multiresistant S. Saintpaul clonal line is widespread in turkeys and turkey products in Germany and was also detected among German human fecal and Dutch poultry isolates.


2004 ◽  
Vol 48 (11) ◽  
pp. 4130-4135 ◽  
Author(s):  
Kyungwon Lee ◽  
Dongeun Yong ◽  
Jong Hwa Yum ◽  
Young Sik Lim ◽  
Hyun Sook Kim ◽  
...  

ABSTRACT A chloramphenicol-resistant strain of Salmonella enterica serovar Typhi was first noted in Korea in 1992, when a resistant isolate was detected in a returned traveler. Continued isolation of multidrug-resistant (MDR) strains thereafter in other settings prompted a retrospective analysis of laboratory records and phenotypic and genotypic analyses of 12 chloramphenicol-resistant isolates. Among these, one isolate was resistant only to chloramphenicol, and the other isolates were also resistant to ampicillin and co-trimoxazole. MDR was transferred by conjugation from 9 of the 11 isolates. PCR showed that all isolates had an incompatible group HI1 plasmid, and oriT was detected in 10 isolates, which included strains with an unsuccessful transfer of resistance. All of the ampicillin-resistant isolates had a β-lactamase band of pI 5.4 and bla TEM alleles. A PCR amplicon from an isolate showed that the sequences were identical to those of bla TEM-1, suggesting that all isolates had a TEM-1 β-lactamase. All isolates had class 1 integrons: 10 isolates had integrons of ca. 1.2 kb with dhfr7 gene cassettes, and 1 isolate had an integron of ca. 2.3 kb with aacA4 and bla OXA-1-like gene cassettes. The pulsed-field gel electrophoresis patterns of 7 of 11 MDR isolates were identical and indistinguishable from those reported for isolates in India and Indonesia. In conclusion, some of the MDR strains in Korea are related to those in other Asian countries. Susceptibility testing became necessary for selection of antimicrobial agents for the optimal treatment of patients with the emergence of MDR Salmonella serovar Typhi in Korea.


2019 ◽  
Vol 147 ◽  
Author(s):  
S. Yukawa ◽  
I. Uchida ◽  
Y. Tamura ◽  
S. Ohshima ◽  
T. Hasegawa

AbstractDog treats might be contaminated withSalmonella. In Canada and the USA, outbreaks of human salmonellosis related to exposure to animal-derived dog treats were reported. Consequently, surveillance data onSalmonellacontamination of dog treats have been gathered in many countries, but not in Japan. In the current study, we investigated whether dog treats in Japan were contaminated withSalmonella. Overall, 303 dog treats (of which 255 were domestically produced) were randomly collected and the presence ofSalmonellainvestigated. Seven samples were positive forSalmonella entericasubsp.enterica. Among these isolates, three were identified as serovar 4,5,12:i:–; two were serovar Rissen; and two were serovar Thompson. All serovar 4,5,12:i:– and Thompson isolates were resistant to one or more drugs. Two serovar Rissen isolates were fully susceptible to all tested antimicrobial agents. AllSalmonellaisolates were susceptible to cefotaxime, ciprofloxacin and nalidixic acid. The geneblaTEMwas detected in two serovar 4,5,12:i:– isolates. TheblaCTX−MandblaCMYgenes were not detected in any isolates. This study demonstrated that dog treats in Japan could constitute a potential source of dog and humanSalmonellainfections, including multidrug-resistantSalmonellaisolates.


Biologia ◽  
2013 ◽  
Vol 68 (2) ◽  
Author(s):  
Jasmine Kaur ◽  
Swatantra Jain

AbstractTyphoid fever is systemic illness caused by Salmonella enterica serovar Typhi (S. Typhi) in humans. Increasing multidrug resistant strains of S. Typhi and limited effect of available vaccines has necessitated exploring of new immunogens for protection against it. Earlier studies have shown that a crude preparation of outer membrane proteins (OMPs) of S. Typhi evokes strong immune response and induces a protective immunity against infection caused by diverse Gram-negative bacteria. In the present study we have evaluated the protective effect of a purified recombinant 49 kDa (r49kDa) OMP of S. Typhi alone or along with alum or complete Freund’s adjuvant, against a challenge by S. Typhi (0.4 × 50% lethal dose) by biochemical estimation of serum enzymes and oxidative stress enzymes in Swiss albino mice. There was a decrease in activity of alanine aminotransferase by 14.28%, 38.09%, 23.80%; aspartate aminotransferase by 6.25%, 25%, 16.25%; lipid peroxidation by 4.34%, 18.84%, 11.59%; and catalase by 8%, 14%, 10%, respectively, whereas increase in activity of reduced glutathione by 33.33%, 61.11%, 44.44%; glutathione peroxidase by 7%, 16%, 10%; and glutathione reductase by 8%, 20%, 12%, respectively, as compared to control animals challenged with bacteria without pre-immunization. The results indicated that immunization of mice with r49kDa OMP alone or in combination with adjuvants protected and normalized the liver. It reduces the development of oxidative stress in mice against Salmonella infection and the risk of getting typhoid. These results represent an additional supplement to our earlier reported data on protective immunity evoked by this protein.


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