Antimicrobial Resistance and Genetic Diversity of
            <i>Shigella sonnei</i>
            Isolates from Western Ireland, an Area of Low Incidence of Infection

DeLappe, Niall; O’Halloran, Fiona; Fanning, Séamus; Corbett-Feeney, G.; Cheasty, T.; Cormican, Michael T.

doi:10.1128/jcm.43.8.4309.2005

Cited by 21 publications

(35 citation statements)

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“…In this study, class 1 integrons were the most prevalent, in keeping with the results of other studies of African Shigella isolates [18]. In contrast, integron prevalence is very low in other parts of the world [20,21,22]. We found class 2 integrons in half the 32 strains studied here.…”

Section: Discussionsupporting

confidence: 77%

“…The high prevalence of dfr and aadA1 gene cassettes in integron-containing Shigella strains may thus be related to the use of these antibiotics. However, the dfr and aadA cassettes are also very common in integrons harboured by other Enterobacteriaceae species isolated from patients in industrialized countries [20,21]. In a previous study in Senegal we also found a high prevalence of dfr and aadA cassettes in integron-containing enteroaggregative and enteroinvasive Escherichia coli (E. coli) strains [31].…”

Section: Discussionmentioning

confidence: 74%

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High prevalence of trimethoprim-resistance cassettes in class 1 and 2 integrons in Senegalese Shigella spp isolates

Sow

Aı̈dara-Kane

Barraud

et al. 2010

J Infect Dev Ctries

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Background: Integrons have a well-established role in the dissemination of resistance among Gram-negative pathogens and are thus a useful marker of antibiotic resistance. Shigellae are noteworthy for their multiple drug resistance, having gradually acquired resistance to most widely use and inexpensive antimicrobial drugs. Methodology: A total of 32 Shigella strains belonging to serotypes flexneri, dysenteriae, and boydii 20, a new Shigella serovar, resistant to at least four antibiotics were analyzed by molecular techniques. Results: Class 1 integrons were the most prevalent (92.8%); class 2 integrons were found in 16 strains (57.1%). Fifty percent of the strains harboured both class 1 and 2 integrons (intI1 and intI2 genes); this combination of integrase genes was most prevalent in S. boydii 20 and S. dysenteriae strains. The class 1 integrons detected contained dfr and aadA cassettes, alone or in combination (dfrA5/dfrA15, or dfrA15-aadA1, dfrA1-aadA2), and an atypical cassette array with an insertion sequence (oxa30-aadA1-IS1). For class 2 integrons, we detected either the same cassettes as those found in Tn7 (dfrA1-sat1-aadA1-orfX) or truncated class 2 integrons without aadA1 or orfX. The tns genes were absent from all class 2 integrons. The distribution of integrons among RAPD profiles and serotypes revealed a clonal spread of integrons into serotypes and a transfer of integrons between different serotypes. Conclusions: The detection of integrons in a new Shigella serovar, in addition with a high integron prevalence among Shigella strains, confirms the propensity of shigellae to acquire and disseminate resistance determinants.

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Section: Discussionsupporting

confidence: 77%

Section: Discussionmentioning

confidence: 74%

High prevalence of trimethoprim-resistance cassettes in class 1 and 2 integrons in Senegalese Shigella spp isolates

Sow

Aı̈dara-Kane

Barraud

et al. 2010

J Infect Dev Ctries

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“…At the present time, Cip is still one of the most potent antimicrobials available for medical treatment of invasive gastrointestinal infections in adults (7). Even a decrease in susceptibility to fluoroquinolones has become a major problem in medical practice.…”

Section: Discussionmentioning

confidence: 99%

“…In gram-negative clinical isolates, capture and spread of antibiotic resistance determinants by integrons underlies the rapid evolution of MDR phenotypes (18). It is well known that in S. sonnei, class 2 integrons are most frequently detected (2,7,17). They are associated with transposon Tn7 and are known to carry a classic gene cassette with three resistance genes, namely, dihydrofolate reductase (dfrA1), streptothricin acetyltransferase (sat1), and aminoglycoside adenyltransferase (aadA1), conferring resis- tance to Tmp, to streptothricin, and to Str and spectinomycin, respectively (8).…”

Section: Discussionmentioning

confidence: 99%

Surveillance of Antibiotic Susceptibility Patterns among Shigella sonnei Strains Isolated in Belgium during the 18-Year Period 1990 to 2007

Vrints¹,

Mairiaux

Meervenne³

et al. 2009

J Clin Microbiol

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This study was conducted to determine the frequency and pattern of antimicrobial susceptibility of Shigella sonnei, the predominant species causing shigellosis in Belgium. Between 1990 and 2007, a total of 7,307 strains, mainly (98.2%) isolated from stools, were diagnosed by peripheral laboratories before being confirmed as Shigella strains by serotyping by the National Reference Center of Salmonella and Shigella. A significant increase in resistances to tetracycline, streptomycin, trimethoprim, sulfonamides, and cotrimoxazole (i.e., trimethoprim in combination with sulfonamides) was observed during this period. Since 1998, resistance to nalidixic acid also increased to reach a peak (12.8%) of resistant isolates in 2004. Concomitantly, multidrug resistance (MDR) in this species emerged in 2007, with 82% of total isolates being MDR. However, during this 18-year period, all isolates remained fully susceptible to ciprofloxacin and gentamicin. The work includes the molecular characterization of mechanisms of resistance to ampicillin, tetracycline, chloramphenicol, and cotrimoxazole and class 1 and class 2 integrons. S. sonnei acquired antimicrobial resistance to traditional antibiotics (ampicillin and tetracycline) by horizontal gene transfer, while the genetic stability of transposons was responsible for a high (89%) proportion of resistance to a commonly prescribed antibiotic (cotrimoxazole). Therefore, cotrimoxazole should no longer be considered appropriate as empirical therapy for treatment of shigellosis in Belgium when antibiotics are indicated. Rates of resistance to nalidixic acid should also be attentively monitored to detect any shift in fluoroquinolone resistance, because it represents the first line among antibiotics used in the treatment of shigellosis.

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“…The results of genetic clustering analysis indicated that infection with a specific strain was confined to a In recent years, the rates of integron-associated multidrug resistance have increased rapidly, such as resistance type ACSSuT (ampicillin, chloramphenicol, streptomycin, trimethoprim-sulfamethoxazole, and tetracycline resistance) in the family Enterobacteriaceae, primarily in S. enterica serovar Typhimurium DT104, but also in Shigella spp. (8,17,27). As shown in Table 2, among the S. flexneri isolates, 2 type 4a strains belonging to antibiogram types G and H had the ACSSuT resistance type, 22 type 1a strains (antibiogram type A) had the ACST resistance type (resistance to ampicillin, chloramphenicol, streptomycin, and tetracycline), and 5 type 1a strains (antibiogram type B) had the ACS resistance type (resistance to ampicillin, chloramphenicol, and streptomycin).…”

Section: Pfge Typing and Dendrograms Of The S Flexneri Isolatesmentioning

confidence: 99%

Molecular Epidemiology ofShigella flexneriin a Long-Stay Psychiatric Nursing Center during 2001 to 2003

Lee

Liu

et al. 2005

J Clin Microbiol

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With six separate wards accommodating more than 1,600 patients, V Nursing Center (VNC) is a long-stay psychiatric nursing center in eastern Taiwan. During 2001 to 2003, 39 shigellosis cases occurred in VNC. Different from the notion that most cases of shigellosis are caused by Shigella sonnei, all except one of these cases were caused by S. flexneri, with the remaining one caused by an S. sonnei isolate. O-antigen serotyping showed that the 38 S. flexneri strains were of either type 1a (n ‫؍‬ 20) or 4a (n ‫؍‬ 18), two less prevalent serotypes in Taiwan. NotI-based pulsed-field gel electrophoresis analyses performed with 8 type 1a non-VNC strains and 9 type 4a non-VNC strains isolated from 1996 to 2003 for comparison divided the 28 type 1a strains and the 27 type 4a strains into 7 and 10 subtypes, designated subtypes P1A to P1G and subtypes P4A to P4J, respectively. Subtypes P1A and P4A, which appeared in three consecutive years in VNC as well as outside of VNC, are the most prevalent subtypes. Analyses of the relatedness of the VNC strains on the basis of the banding patterns grouped the type 1a and 4a strains into four and five clusters, respectively. All except one of the type 1a strains had 95% similarity, indicating that they had a common parent, whereas the type 4a strains had similarities that ranged from 77 to 93%, suggesting that they were of diverse origins. In two of the outbreaks, less related subtypes of the type 4a strains were found in the same VNC wards in consecutive years, suggesting the possible existence of different subtypes in VNC all the time. Antibiotic susceptibility testing showed that all except one of the S. flexneri strains were sensitive to at least seven antibiotics; the remaining isolate was sensitive to three antibiotics. The data from the latter tests should be helpful for selection of proper treatments for S. flexneri infections in Taiwan.

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Antimicrobial Resistance and Genetic Diversity of Shigella sonnei Isolates from Western Ireland, an Area of Low Incidence of Infection

Cited by 21 publications

References 0 publications

High prevalence of trimethoprim-resistance cassettes in class 1 and 2 integrons in Senegalese Shigella spp isolates

High prevalence of trimethoprim-resistance cassettes in class 1 and 2 integrons in Senegalese Shigella spp isolates

Surveillance of Antibiotic Susceptibility Patterns among Shigella sonnei Strains Isolated in Belgium during the 18-Year Period 1990 to 2007

Molecular Epidemiology ofShigella flexneriin a Long-Stay Psychiatric Nursing Center during 2001 to 2003

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