rDNA fingerprinting as a tool in epidemiological analysis ofSalmonella typhiinfections

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.

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rRNA gene restriction patterns and biotypes ofShigella sonnei

Epidemiology and Infection ◽

10.1017/s0950268800050640 ◽

1993 ◽

Vol 110 (1) ◽

pp. 23-30 ◽

Cited By ~ 16

Author(s):

A. Nastasi ◽

S. Pignato ◽

C. Mammina ◽

G. Giammanco

Keyword(s):

Phage Type ◽

Strain Differences ◽

Extended Period ◽

Diarrhoeal Disease ◽

Restriction Pattern ◽

Resistance Pattern ◽

Rrna Gene ◽

Chromosomal Dna ◽

Bacterial Clone ◽

Gene Restriction

SUMMARYShigella sonneiis a major agent of diarrhoeal disease in developed as well as in developing countries. Several phenotypic methods to define strain differences have been applied to this species ofShigellaincluding, more recently, analysis of extrachromosomal and chromosomal DNA.In this study, 432 endemic and epidemic strains isolated between 1975 and 1991 in Italy, France and Switzerland were submitted to rRNA gene restriction pattern analysis, after digestion of whole-cell DNA byHincII, and to concomitant biotyping.Thirteen ribotypes, HI to H13, and five biotypes, a, d, e, f, g, were detected. Xinety-five percent of the sporadic strains were assigned to ribotypes HI to H4, which could be subtvped, except for H4, in different biotypes. Strains from each of seven different outbreaks had indistinguishable ribotype-biotype patterns. In contrast, 65 strains, isolated in Sicily in 1980 over an extended period of apparently epidemic increase of isolations and which had previously been considered to be a single bacterial clone on the basis of resistance pattern and phage type, were found to belong to two different and scarcely related ribotypes.Ribotyping and biochemical subtyping appear to be a useful epidemiological tool in studies on the circulation and distribution of strains ofS. sonnei.

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Phage Types of multidrug resistant Salmonella species in a rural area of Maharashtra, India

Bangladesh Journal of Medical Science ◽

10.3329/bjms.v11i1.9821 ◽

1970 ◽

Vol 11 (1) ◽

pp. 37-39

Author(s):

ST Sabiha ◽

SL Nilekar

Keyword(s):

Antimicrobial Susceptibility ◽

Phage Type ◽

Antibiotic Sensitivity ◽

Salmonella Typhi ◽

Multidrug Resistant ◽

Phage Typing ◽

Diffusion Method ◽

Inappropriate Use ◽

Phage Types ◽

Sensitivity Pattern

Objective: The aim of the present study is to know Phage typing and antimicrobial susceptibility pattern of Salmonella species. Methods: A total of 32 Salmonella species isolated from stool and blood specimen were included in the study. They were sent for phage typing to Lady Hardinge Medical College, New Delhi. Antimicrobial susceptibility was done by using Kirby Bauer disc diffusion method. Results: Majority of Salmonella typhi belongs to phage type E1 and biotype I. Decreased susceptibility of the isolate was observed to Ampicillin, Cotrimoxazole, Cephalexin and Gentamicin. Majority of the isolates were sensitive to Ciprofloxacin. Conclusion: Predominant phage type was E1. The antibiotic sensitivity pattern is changing and resistant cases are emerging due to inappropriate use of antibiotics. DOI: http://dx.doi.org/10.3329/bjms.v11i1.9821 BJMS 2012; 11(1): 37-39

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Characterization ofNeisseria meningitidisisolates by ribosomal RNA gene restriction patterns and restriction endonuclease digestion of chromosomal DNA

Epidemiology and Infection ◽

10.1017/s0950268800048901 ◽

1991 ◽

Vol 107 (2) ◽

pp. 253-262 ◽

Cited By ~ 6

Author(s):

J. Z. Jordens ◽

T. H. Pennington

Keyword(s):

Neisseria Meningitidis ◽

Restriction Endonuclease ◽

Ribosomal Rna ◽

Restriction Pattern ◽

Rrna Gene ◽

Restriction Endonuclease Digestion ◽

Chromosomal Dna ◽

Restriction Patterns ◽

Gene Restriction ◽

Endonuclease Digestion

SUMMARYThe use of ribosomal RNA (rRNA) gene restriction patterns to study the molecular epidemiology ofNeisseria meningitidiswas investigated. Ninety-four isolates ofNeisseria meningitidiswere characterized by their rRNA gene restriction patterns with 16 + 23 S rRNA fromEscherichia colias a probe. Thirteen rRNA gene restriction patterns were recognized; each of these patterns represented between 1 and 30 isolates. Isolates with the outbreak-associated phenotype B15P1.16 (sulphonamide resistant) all gave a single rRNA gene restriction pattern but this pattern also contained isolates with other phenotypes. Further discrimination between isolates was achieved by comparison of banding patterns resulting from restriction endonuclease digestion of chromosomal DNA withBglII. This gave a banding pattern consisting of about ten bands which was simple to interpret. Using this technique 94 isolates were classified in 54 patterns containing between 1 and 14 isolates. Restriction endonuclease analysis withBglII characterized outbreak-associated isolates with the phenotype B15P1.16 and enabled strains not typable by conventional methods to be identified as probable outbreak-associated isolates. The techniques should prove useful for epidemiological studies.

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The distribution of serotype-specific plasmids among different subgroups of strains ofSalmonella entericaserotype Enteritidis: characterization of molecular variants by restriction enzyme fragmentation patterns

Epidemiology and Infection ◽

10.1017/s0950268800051888 ◽

1995 ◽

Vol 114 (1) ◽

pp. 25-40 ◽

Cited By ~ 11

Author(s):

S. C. Rankin ◽

C. E. Benson ◽

D. J. Platt

Keyword(s):

Restriction Enzyme ◽

Salmonella Enterica ◽

Phage Type ◽

Restriction Enzymes ◽

Additional Restriction ◽

Fragmentation Pattern ◽

Phage Types ◽

Molecular Variants ◽

Fragmentation Patterns

SUMMARYFour hundred and thirty-four isolates ofSalmonella entericaserotype Enteritidis were studied. They were grouped into five subsets defined by either the collection criteria or the parameter which formed the basis for subsequent analysis. Seventy-seven per cent harboured the serotype-specific plasmid (SSP). In 55% of the isolates this was the sole plasmid. Molecular variation in the SSP was detected in 17 (5%) of the isolates on the basis of restriction enzyme fragmentation pattern (REFP) analysis usingPstI andSmaI. The SSP variants were further characterized using additional restriction enzymes chosen to optimize the information content and analysed using a coefficient of similarity.A variant SSP designated pOG690 showed greater resemblance to the SSP ofSalmonella entericaserotype Typhimurium than Enteritidis; 89% and 68% respectively forPstI and 79% and 55% respectively forSmaI. In respect of thePstI data pOG690 shared at least 55 kb of DNA with the Typhimurium SSP and 37 kb with the SSP of Enteritidis. This variant was associated with poultry (duck, goose, chicken) and all isolates belonged to phage type 9b. Other variants were associated with phage types 4, 6, 6a, 9a, 11, 15 and 24. The epidemiological implications of these results are discussed.

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Characterization of multi-drug resistant Salmonella typhi isolated from Pakistan

Epidemiology and Infection ◽

10.1017/s0950268899003453 ◽

2000 ◽

Vol 124 (1) ◽

pp. 9-16 ◽

Cited By ~ 18

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.

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Characterization of resistance plasmids and carried phages in an epidemic clone of multi-resistantSalmonella typhimuriumin India

Journal of Hygiene ◽

10.1017/s0022172400070066 ◽

1982 ◽

Vol 88 (2) ◽

pp. 193-204 ◽

Cited By ~ 27

Author(s):

J. A. Frost ◽

B. Rowe ◽

L. R. Ward ◽

E. J. Threlfall

Keyword(s):

Phage Type ◽

Paediatric Hospital ◽

Phage Types ◽

Hospital Outbreak ◽

Group I ◽

Severe Gastroenteritis ◽

Single Clone ◽

Compatibility Group ◽

Resistant Strains

SummaryHospital outbreaks of severe gastroenteritis caused by multi-resistantSalmonellatyphimuriumhave occurred in a number of cities throughout India since 1977. The strains involved belong to phage types 66 or 122, or are untypable; the latter are derived from types 66 or 122 by acquisition of one or more of a number of temperate bacteriophages. Types 66 and 122 are closely related and react with the same phages of theS. typhimuriumtyping scheme.A plasmid belonging to compatibility group FImeencoding resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, sulphonamides, spectinomycin, tetracyclines, gentamicin and trimethoprim (R-type ACKSSuSpTGTm) is present in all of the multi-resistant strains. Several other plasmids have been identified including an SSu resistance determinant, a group I2, transfer factor and an R factor coding for resistance to kanamycin, streptomycin and sulphonamides which is compatible with plasmids of all the standard compatibility groups. These plasmids are only present in a proportion of the strains examined.Examination of strains from other sources has identified a paediatric hospital outbreak in Saudi Arabia and a number of sporadic infections in Great Britain which have been caused by the same organisms. These studies show that, despite differences in phage type and plasmid content, this group of strains belongs to a single clone which has become widespread in India with some extension to other countries.

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Molecular characterization of plasmids in Salmonella enteritidis phage types

Epidemiology and Infection ◽

10.1017/s0950268800068126 ◽

1993 ◽

Vol 110 (2) ◽

pp. 209-216 ◽

Cited By ~ 18

Author(s):

D. J. Brown ◽

E. J. Threlfall ◽

M. D. Hampton ◽

B. Rowe

Keyword(s):

Molecular Weight ◽

Dna Hybridization ◽

Type Strain ◽

Salmonella Enteritidis ◽

Phage Type ◽

Oligonucleotide Probes ◽

Phage Types ◽

Type Strains ◽

Weight Groups

SUMMARYPlasmids in selected type strains of 26 of the Salmonella enteritidis phage types have been characterized by restriction enzyme fingerprinting and by DNA–DNA hybridization with oligonucleotide probes for Salmonella plasmid virulence (Spv) genes. With one exception, the fingerprints of the 38 MDa plasmids studied were homogeneous but there was heterogeneity in the fingerprints of 59 MDa plasmids found in 4 of the type strains. However all 38 MDa and 59 MDa plasmids were related as was a 45 MDa plasmid identified in the type strain of phage type 19. A 3·5 kb fragment homologous to SpvC was conserved in Hind III digests of all 38 MDa and 59 MDa plasmids, and in the related 45 MDa plasmid. In contrast a 65 MDa plasmid found in the type strain of phage type 10 was not related to these three plasmid molecular weight groups and did not carry the SpvC gene.

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Salmonellosis in Indonesia: phage type distribution of Salmonella typhi

Journal of Hygiene ◽

10.1017/s0022172400025560 ◽

1979 ◽

Vol 82 (1) ◽

pp. 143-153 ◽

Cited By ~ 4

Author(s):

Warren R. Sanborn ◽

J.-F. Vieu ◽

S. Komalarini ◽

Sinta ◽

R. Trenggonowati ◽

...

Keyword(s):

Antibiotic Resistance ◽

East Asia ◽

Reductase Activity ◽

Phage Type ◽

Salmonella Typhi ◽

South East Asia ◽

Type Distribution ◽

Phage Types ◽

Steady Level ◽

Large Groups

SUMMARYThe distribution of phage types was studied among 577 strains of Salmonella typhi from Indonesia. Chemotype, colicinogeny, and tetrathionate reductase activity were also studied for most of these strains. The current phage type formula for Java was determined to be: A, D2, D6, E1a, E2, M1, and 46, but two other large groups of strains were also found, I +IV and degraded Vi + strains. Significant differences in S. typhi strain distributions were noted between two localities on Java with respect to phage type and tetrathionate reductase activity. Comparisons were made with past phage typing studies in Jakarta as well as with more recent studies in other parts of south-east Asia. Phage types A, Dl, D2, and El persisted at a rather steady level in Jakarta for 28 years. Evidence was found for epidemiological links to European and Asian areas. Antibiotic resistance among these Indonesian S. typhi strains was rare.

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Molecular characterization of multiresistant strains ofSalmonella typhifrom South Asia isolated in Ontario, Canada

Canadian Journal of Microbiology ◽

10.1139/w98-012 ◽

1998 ◽

Vol 44 (4) ◽

pp. 356-363 ◽

Cited By ~ 10

Author(s):

N Harnett ◽

S McLeod ◽

Y AuYong ◽

J Wan ◽

S Alexander ◽

...

Keyword(s):

Molecular Weight ◽

South Asia ◽

Antimicrobial Agents ◽

Phage Type ◽

Salmonella Typhi ◽

Mercury Resistance ◽

Temperature Sensitive ◽

K 12 ◽

Multiresistant Strains

Two hundred and fourteen isolates of Salmonella typhi submitted to our laboratory between 1992 and 1996 were tested for susceptibility to 20 antimicrobial agents. Forty-eight of the 214 isolates (22.4%), recovered from individuals who had travelled in South Asia, were multiresistant. Forty-four of the 48 isolates were resistant to ampicillin, chloramphenicol, tetracycline, streptomycin, sulfamethoxazole, trimethoprim, cotrimoxazole, ticarcillin, and piperacillin; the other four isolates were resistant to four to six agents. Forty-two of the multiresistant isolates belonged to Vi phage type E1, two isolates from the Punjab State belonged to phage type A, another from the Punjab State belonged to phage type E3, one isolate from Pakistan belonged to type M1, and one isolate from India belonged to type J1. Plasmids from 45 of 48 isolates showed a temperature-sensitive mechanism of transfer to Escherichia coli K-12 strains, characteristic of HI incompatibility group plasmids. The majority of plasmids had an estimated molecular weight of 120 MDa and encoded both citrate utilization and mercury resistance. Plasmids from three isolates had an estimated molecular weight of 112-115 MDa; one of these isolates encoded citrate utilization but not mercury resistance. Analysis of isolates by pulsed-field gel electrophoresis after digestion with XbaI and SpeI indicated that the majority of multiresistant isolates shared a common restriction profile, while four isolates had unique patterns.Key words: typing, multiresistant, Salmonella typhi.

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