scholarly journals Characterization of multi-drug resistant Salmonella typhi isolated from Pakistan

2000 ◽  
Vol 124 (1) ◽  
pp. 9-16 ◽  
Author(s):  
P. M. A. SHANAHAN ◽  
K. A. KARAMAT ◽  
C. J. THOMSON ◽  
S. G. B. AMYES
Keyword(s):  
Susceptibility Testing ◽  
Antibiotic Resistance Genes ◽  
Salmonella Typhi ◽  
Pulsed Field Gel Electrophoresis ◽  
Type I ◽  
Drug Resistant ◽  
Antibiotic Susceptibility Testing ◽  
Chromosomal Dna ◽  
Incompatibility Group

Thirty-nine strains of Salmonella typhi, isolated in 1995 from four Districts in Pakistan, Rawalpindi, Islamabad, Kharian and Jehlem, were catalogued and examined. Chromosomal DNA from each isolate was digested with XbaI restriction endonuclease and subjected to pulsed-field gel electrophoresis. Three clonal variants comprising of 17–19 DNA fragments were identified. Antibiotic susceptibility testing identified that 37 of the S. typhi were resistant to chloramphenicol, trimethoprim and ampicillin. These antibiotic resistance genes were found to be located on one of four plasmids belonging to incompatibility group IncHI1 and ranging in size from 150–175 Kb. The genes responsible for this resistance in each case were the chloramphenicol acetyltransferase (CAT) type I, the dihydrofolate reductase (DHFR) type VII and the β-lactamase TEM-1 respectively.

Characterisation ofStaphylococcus aureusstrains isolated from mastitis bovine milk in Argentina

2018 ◽  
Vol 85 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Mariela E Srednik ◽  
Valentine Usongo ◽  
Sarah Lépine ◽  
Xavier Janvier ◽  
Marie Archambault ◽  
...  
Keyword(s):  
Large Scale ◽  
Susceptibility Testing ◽  
Restriction Analysis ◽  
Bovine Milk ◽  
Dairy Herds ◽  
Antibiotic Susceptibility Testing ◽  
Chromosomal Dna ◽  
Isolation Rate ◽  
Milk Samples ◽  
Mastitic Milk

The study reported in this Research Communication was conducted to characteriseStaphylococcus aureusisolates recovered from mastitic bovine milk from dairy herds in Argentina. A total of 829 mastitic milk samples, both clinical and subclinical, were collected from 21 farms by veterinarians and submitted to the laboratory for testing from which 229S. aureusisolates were recovered, an isolation rate of 28·1%. These isolates were tested for susceptibility to the antibiotics penicillin, erythromycin and clindamycin. Of the 229 isolates, 53 (23·1%) were resistant to penicillin, 31 (13·5%) to erythromycin and 28 (12·2%) to clindamycin. All isolates were negative for themecA,mecC andpvlgenes by PCR. Southernblot hybridisation revealed that theermC gene was located on plasmid bands. Eighty isolates were randomly selected from the 229 for further characterisation. Restriction analysis of chromosomal DNA with Cf9I followed by PFGE of the 80 isolates revealed 23 distinct pulsotypes at 80% similarity. Seven major types (A, B, N, P, S, T, U and V) accounted for 68·7% of these isolates and 12 pulsotypes (A, B, F, G, J, K, M, N, P, S, T and U) occurred on more than one farm indicating genetic diversity within the farms. MLST of a representative isolate from dominant types identified the STs 97 705, 746, 2102 and 2187 with ST97 being the most predominant. Antibiotic susceptibility testing showed that 53·7% of the 80 randomly selected isolates were resistant to at least one of the three antibiotics tested. To our knowledge, this study represents the first large scale molecular studies onS. aureusisolates from dairy farms in Argentina.

scholarly journals Molecular Characterization of a Novel Plasmid-Encoded Cefotaximase (CTX-M-12) Found in Clinical Klebsiella pneumoniae Isolates from Kenya

2001 ◽  
Vol 45 (7) ◽  
pp. 2141-2143 ◽  
Author(s):  
S. Kariuki ◽  
J. E. Corkill ◽  
G. Revathi ◽  
R. Musoke ◽  
C. A. Hart
Keyword(s):  
Klebsiella Pneumoniae ◽  
Gel Electrophoresis ◽  
Direct Sequencing ◽  
Hydrolytic Activity ◽  
Pulsed Field Gel Electrophoresis ◽  
Chromosomal Dna ◽  
National Hospital ◽  
Cephalosporin Resistance ◽  
M 12

ABSTRACT Nine Klebsiella pneumoniae isolates, six from blood and three from cerebrospinal fluid of newborn babies at Kenyatta National Hospital, Nairobi, Kenya, were analyzed for the mechanism of cephalosporin resistance. By using pulsed-field gel electrophoresis ofXbaI-digested chromosomal DNA, all the nine isolates were found to be clonal. PCR and direct sequencing revealed a novel extended-spectrum β-lactamase, which we designated CTX-M-12. It has a more potent hydrolytic activity against cefotaxime than against ceftazidime and a pI of 9.0 and is encoded on a large self-transferable ca. 160-kbp plasmid.

Characteristics of enteroaggregative Escherichia coli isolated from healthy carriers and from patients with diarrhoea

2013 ◽  
Vol 62 (12) ◽  
pp. 1828-1834 ◽  
Author(s):  
Magdalena T. Nüesch-Inderbinen ◽  
Eveline Hofer ◽  
Herbert Hächler ◽  
Lothar Beutin ◽  
Roger Stephan
Keyword(s):  
Escherichia Coli ◽  
Susceptibility Testing ◽  
Antibiotic Susceptibility Testing ◽  
Aetiological Agent ◽  
Healthy Humans ◽  
Faecal Samples ◽  
Gene Typing ◽  
Stool Samples ◽  
Healthy Carriers

The aim of this study was to compare the virulence characteristics and phylogenetic features of enteroaggregative Escherichia coli (EAEC) strains from adults with and without diarrhoea and to search for associations between the analysed genes and carrier or diarrhoeagenic strains, respectively. Faecal samples of 487 healthy humans were screened for EAEC strains and compared with isolates from diarrhoeal patients. Virulence and virulence-associated gene typing, serotyping, multilocus sequence typing and antibiotic susceptibility testing were performed for characterization of the isolates. Characteristics significantly linked to carrier strains or to diarrhoeagenic strains were determined. From 487 stool samples, 24 EAEC strains were obtained. Comparison with strains originating from diseased persons showed a statistically significant association of the genes sat (P = 0.002) and agg3C (P = 0.0139) with the carrier strains, and of pCVD432 (P = 0.0001), aap (P = 0.003), aggR (P = 0.0048) and air (P = 0.031) with the diarrhoeagenic strains. Our study indicates that a certain subset of EAEC is unrelated to diarrhoea, for which sat and agg3C may be markers. Our results further suggest that diarrhoeagenic EAEC strains are distinguishable from carrier strains and suggest that, in addition to well-established markers such as pCVD432 and aggR, aap and air may be useful additional markers to define EAEC as an aetiological agent of diarrhoea in adults.

scholarly journals Molecular Epidemiology of Penicillin-NonsusceptibleStreptococcus pneumoniae among Children in Greece

2000 ◽  
Vol 38 (12) ◽  
pp. 4361-4366 ◽  
Author(s):  
Debby Bogaert ◽  
George A. Syrogiannopoulos ◽  
Ioanna N. Grivea ◽  
Ronald de Groot ◽  
Nicholas G. Beratis ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Molecular Epidemiology ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Genetic Relatedness ◽  
Antibiotic Susceptibility Testing ◽  
Penicillin Binding Protein ◽  
Genetic Clusters

A total of 145 penicillin-nonsusceptible Streptococcus pneumoniae strains were isolated from young carriers in Greece and analyzed by antibiotic susceptibility testing, serotyping, restriction fragment end labeling (RFEL), and penicillin-binding protein (PBP) genotyping. The serotypes 23A and 23F (54%), 19A and 19F (25%), 9V (5%), 15A, 15B, and 15C (4%), 6A and 6B (4%), and 21 (4%) were most prevalent in this collection. Fifty-three distinct RFEL types were identified. Sixteen different RFEL clusters, harboring 2 to 32 strains each, accounted for 82% of all strains. Eight of these genetic clusters representing 60% of the strains were previously identified in other countries. A predominant lineage of 66 strains (46%) harboring five RFEL types and the serotypes 19F and 23F was closely related to the pandemic clone Spain23F-1 (genetic relatedness of ≥85%). Another lineage, representing 11 strains, showed close genetic relatedness to the pandemic clone France9V-3. Another lineage of 8 serotype 21 strains was Greece specific since the RFEL types were not observed in an international collection of 193 genotypes from 16 different countries. Characterization of the PBP genes pbp1a, pbp2b, and pbp2x revealed 20 distinct PBP genotypes of which PBP type 1-1-1, initially observed in the pandemic clones 23F and 9V, was predominantly present in 11 RFEL types in this Greek collection of penicillin-nonsusceptible strains (55%). Sixteen PBP types covering 52 strains (36%) were Greece specific. This study underlines the strong contribution of penicillin-resistant international clones to the prevalence and spread of penicillin-nonsusceptible pneumococci among young children in Greece.

scholarly journals Leuconostoc pseudomesenteroides as a Cause of Nosocomial Urinary Tract Infections

1999 ◽  
Vol 37 (12) ◽  
pp. 4124-4126 ◽  
Author(s):  
Elisabete A. Cappelli ◽  
Rosana R. Barros ◽  
Thereza Cristina F. Camello ◽  
Lúcia M. Teixeira ◽  
Vânia Lúcia C. Merquior
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Chromosomal Dna ◽  
Vancomycin Resistant ◽  
Tract Infections ◽  
Relationship Of ◽  
Leuconostoc Pseudomesenteroides

The phenotypic and genotypic characterization of five clinical isolates of Leuconostoc pseudomesenteroides associated with nosocomially acquired urinary tract infections is described. All the strains were susceptible to chloramphenicol, clindamycin, erythromycin, gentamicin, and tetracycline; all were resistant to nalidixic acid, norfloxacin, and vancomycin; and all were intermediately affected by ampicillin and penicillin. Analysis of chromosomal DNA by pulsed-field gel electrophoresis after treatment with SmaI indicated a clonal relationship of the isolates. The results provide evidence for the possibility of nosocomial transmission of this unusual opportunistic, vancomycin-resistant pathogen.

Sequencing and Characterization of Salmonella typhi Plasmid R27 (Incompatibility Group HI1) trhC, a Transfer Gene Encoding a Potential Nucleoside Triphosphate-Binding Domain

Plasmid ◽  
1999 ◽  
Vol 41 (3) ◽  
pp. 207-218 ◽  
Author(s):  
Diane E. Taylor ◽  
Peter J. Newnham ◽  
Craig Sherburne ◽  
Trevor D. Lawley ◽  
Michelle M. Rooker
Keyword(s):  
Salmonella Typhi ◽  
Binding Domain ◽  
Nucleoside Triphosphate ◽  
Transfer Gene ◽  
Incompatibility Group ◽  
Gene Encoding

Coagulase-negative staphylococci from non-mastitic bovine mammary gland: characterization ofStaphylococcus chromogenesandStaphylococcus haemolyticusby antibiotic susceptibility testing and pulsed-field gel electrophoresis

2011 ◽  
Vol 79 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Mateja Pate ◽  
Irena Zdovc ◽  
Jana Avberšek ◽  
Matjaž Ocepek ◽  
Andrej Pengov ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Dairy Cows ◽  
Gel Electrophoresis ◽  
Susceptibility Testing ◽  
Clinical Signs ◽  
Pulsed Field Gel Electrophoresis ◽  
Antibiotic Susceptibility Testing ◽  
Bovine Mammary Gland ◽  
Coagulase Negative Staphylococci ◽  
Milk Samples

During routine microbiological examination of milk samples from dairy cows without clinical signs of mastitis, quarter milk samples of 231 dairy cows from 12 herds were investigated for the presence of coagulase-negative staphylococci (CNS). The isolates were identified on the basis of colony morphology, Gram staining, catalase and coagulase test and the commercial kit, API Staph. CNS was detected in 29% (67/231) of the cows. A total of seven CNS species were identified with the most prevalent beingStaphylococcus (Staph.) chromogenes(30%) andStaph. haemolyticus(28·8%), followed byStaph. simulans(11·2%),Staph. xylosus(11·2%),Staph. epidermidis(7·5%),Staph. hyicus(6·3%) andStaph. sciuri(5%). The predominant species,Staph. chromogenesandStaph. haemolyticus, were further characterized by antibiotic susceptibility testing using the agar disc diffusion method (Kirby-Bauer) and by pulsed-field gel electrophoresis (PFGE). Considerable resistance to ampicillin and penicillin was observed in both species. Isolates with identical or highly similar PFGE profiles were detected at the herd level despite a marked heterogeneity seen for both species. On the basis of somatic cell count, absence of clinical signs of inflammation and heterogeneity of genotypes, we assume that CNS isolated in this study could not be considered as important causative agents of the bovine mammary gland inflammation.

scholarly journals rDNA fingerprinting as a tool in epidemiological analysis ofSalmonella typhiinfections

1991 ◽  
Vol 107 (3) ◽  
pp. 565-576 ◽  
Author(s):  
A. Nastasl ◽  
C. Mammina ◽  
M. R. Villafrate
Keyword(s):  
Phage Type ◽  
Salmonella Typhi ◽  
Restriction Pattern ◽  
Hybridization Technique ◽  
Chromosomal Dna ◽  
Phage Types ◽  
Sporadic Cases ◽  
Type C ◽  
Gene Restriction

SUMMARYCharacterization of 169 strainsof Salmonella typhiof phage types C1, C4, D1and D9isolated in 1975–88 was carried out by rDNA gene restriction pattern analysis. Twenty-four isolates had been recovered during four large waterbone outbreaks in the last 20 years in Sicily; 145 strains, isolated from apparently sporadic cases of infection in Southern Italy in the same period of time, were also examined.Application of rRNA–DNA hybridization technique after digestion of chromosomal DNA withClaI showed the identity of patterns of the epidemic strains of phage types C1and D1, confirming attribution of the outbreaks to single bacterial clones. Patterns of the two available strains of lysotype D9were slightly different, whilst the 12 epidemic strains of phage type C4could be assigned to two distinct patterns scarcely related to each other and, consequently, to two different clones. A considerable heterogeneity was detected among all apparently sporadic isolates of the four phage types under study.This fingerprinting method appears a reliable tool to complement phage typing in characterizing isolates ofS. typhi.In particular, epidemiological features of spread of this salmonella serovar in areas, where simultaneous circulation of indigenous and imported strains occurs, can be elucidated.

Comparative analysis ofShigella sonneibiotype g isolated from paediatric populations in Egypt, 1999–2005

2012 ◽  
Vol 141 (8) ◽  
pp. 1614-1624 ◽  
Author(s):  
J. DEJLI ◽  
R. A. NADA ◽  
A. MANSOUR ◽  
A. A. EL-MONIEM ◽  
M. O. WASFY ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Genetic Similarity ◽  
Susceptibility Testing ◽  
Biochemical Characterization ◽  
Multidrug Resistant ◽  
Pulsed Field Gel Electrophoresis ◽  
Antibiotic Susceptibility Testing ◽  
Severe Diarrhoea ◽  
Plasmid Profiling ◽  
High Degree

SUMMARYStrain characteristics of 51Shigella sonneiisolates obtained from children seeking medical care (MC) and 48 isolates recovered during a prospective diarrhoea birth cohort (BC) study were compared. Biochemical characterization and antibiotic susceptibility testing determined that allS. sonneiisolates were biotype g and multidrug-resistant. Plasmid profiling identified 15 closely related patterns andXbaI pulsed-field gel electrophoresis confirmed the high degree of genetic similarity between isolates. AllS.sonneiisolates harbouredipaHand class II integrase genes and 84·3 and 80% of the MC and BC isolates, respectively carried thesengene. Neither the class I integrase nor thesetgene was detected. Our results indicate thatS. sonneiisolates associated with severe diarrhoea were indistinguishable from those associated with mild diarrhoea. Additional genetic tests with greater discrimination might offer an opportunity to determine genetic differences within the globally disseminating biotype g clone.

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