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Conventional and molecular investigation of Shigella isolates in relation to an outbreak in the area of Isfahan, Iran.

Dibaj R, Aslani MM, Heidarieh P, Hashemi A, Ataei B, Daei-Naser A, Shojaei H - Iran J Microbiol (2013)

Bottom Line: Outbreaks of shigellosis are associated with poor sanitation, natural calamities, contaminated food and crowded living conditions.This diarrheal outbreak appeared to be the result of shigellosis.The serologic testing supports this conclusion, as do the molecular patterns of the Shigella isolates.

View Article: PubMed Central - PubMed

Affiliation: Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.

ABSTRACT

Background and objective: Over 165 million cases of shigellosis occur in the world each year, mostly in developing countries. Outbreaks of shigellosis are associated with poor sanitation, natural calamities, contaminated food and crowded living conditions. In late summer 2006, during the final stage of an outbreak of shigellosis at a vast region of Isfahan province, Naein & Ardestan, our laboratory was assigned to investigate the outbreak in order to determine the causative agent.

Materials and methods: A total of 146 rectal swabs which had been collected from the patients by local laboratories on separate days were screened using a battery of conventional and molecular tests.

Results: Thirteen specimens tested positive for Shigella spp. They were identified as S. sonnei (6, 46.1%), S. dysenteriae (4, 30.8%), S. flexneri (2, 15.4%) and Shigella spp (1, 7.7%) by conventional and molecular microbiological tests. According to ribotyping results the isolates were grouped into 3 distinct clusters encompassing the majority of isolates and a single line of descent representing isolate S122 which was nonreactive with any Shigella polyvalent antisera.

Conclusion: This diarrheal outbreak appeared to be the result of shigellosis. Despite the fact that Shigella sonnei was the predominant organism isolated from patients, the causative agent of outbreak diarrhea remains obscure, since other Shigella species were also involved. The serologic testing supports this conclusion, as do the molecular patterns of the Shigella isolates. Having considered the time of investigation which was in the late stage of the outbreak, it was very likely that a collection of endemic and epidemic clinical samples was screened resulting in isolation of various Shigella species.

No MeSH data available.


Related in: MedlinePlus

Ribotype profiles of Shigella isolates; Lanes MW: Molecular Weight Marker (Citrobacter koseri CIP 105177 DNA was cleaved by MluI restriction endonuclease and the fragments were used as molecular size standards (the sizes are from top to bottom, respectively in base pairs): 16752, 12482, 7330, 6552, 5752, 5098, 4405, 3023, 2778, 1696, 1444 and1171).
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Figure 1: Ribotype profiles of Shigella isolates; Lanes MW: Molecular Weight Marker (Citrobacter koseri CIP 105177 DNA was cleaved by MluI restriction endonuclease and the fragments were used as molecular size standards (the sizes are from top to bottom, respectively in base pairs): 16752, 12482, 7330, 6552, 5752, 5098, 4405, 3023, 2778, 1696, 1444 and1171).

Mentions: DNA from all 13 outbreak Shigella isolates could be digested with endonuclease MluI and were typable. The reference strain of Citrobacter koseri CIP 105177 cleaved by MluI restriction endonuclease used as a molecular marker in the ribotyping (Fig. 1). Reproducibility was perfect and typeability was 100%. A total of 4 distinct ribotypes were obtained. The number of bands composing each ribotype varied from 9 to 13 and fragment sizes ranged from 1.2 to 16.8 Kbp (Fig. 1).


Conventional and molecular investigation of Shigella isolates in relation to an outbreak in the area of Isfahan, Iran.

Dibaj R, Aslani MM, Heidarieh P, Hashemi A, Ataei B, Daei-Naser A, Shojaei H - Iran J Microbiol (2013)

Ribotype profiles of Shigella isolates; Lanes MW: Molecular Weight Marker (Citrobacter koseri CIP 105177 DNA was cleaved by MluI restriction endonuclease and the fragments were used as molecular size standards (the sizes are from top to bottom, respectively in base pairs): 16752, 12482, 7330, 6552, 5752, 5098, 4405, 3023, 2778, 1696, 1444 and1171).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4385158&req=5

Figure 1: Ribotype profiles of Shigella isolates; Lanes MW: Molecular Weight Marker (Citrobacter koseri CIP 105177 DNA was cleaved by MluI restriction endonuclease and the fragments were used as molecular size standards (the sizes are from top to bottom, respectively in base pairs): 16752, 12482, 7330, 6552, 5752, 5098, 4405, 3023, 2778, 1696, 1444 and1171).
Mentions: DNA from all 13 outbreak Shigella isolates could be digested with endonuclease MluI and were typable. The reference strain of Citrobacter koseri CIP 105177 cleaved by MluI restriction endonuclease used as a molecular marker in the ribotyping (Fig. 1). Reproducibility was perfect and typeability was 100%. A total of 4 distinct ribotypes were obtained. The number of bands composing each ribotype varied from 9 to 13 and fragment sizes ranged from 1.2 to 16.8 Kbp (Fig. 1).

Bottom Line: Outbreaks of shigellosis are associated with poor sanitation, natural calamities, contaminated food and crowded living conditions.This diarrheal outbreak appeared to be the result of shigellosis.The serologic testing supports this conclusion, as do the molecular patterns of the Shigella isolates.

View Article: PubMed Central - PubMed

Affiliation: Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.

ABSTRACT

Background and objective: Over 165 million cases of shigellosis occur in the world each year, mostly in developing countries. Outbreaks of shigellosis are associated with poor sanitation, natural calamities, contaminated food and crowded living conditions. In late summer 2006, during the final stage of an outbreak of shigellosis at a vast region of Isfahan province, Naein & Ardestan, our laboratory was assigned to investigate the outbreak in order to determine the causative agent.

Materials and methods: A total of 146 rectal swabs which had been collected from the patients by local laboratories on separate days were screened using a battery of conventional and molecular tests.

Results: Thirteen specimens tested positive for Shigella spp. They were identified as S. sonnei (6, 46.1%), S. dysenteriae (4, 30.8%), S. flexneri (2, 15.4%) and Shigella spp (1, 7.7%) by conventional and molecular microbiological tests. According to ribotyping results the isolates were grouped into 3 distinct clusters encompassing the majority of isolates and a single line of descent representing isolate S122 which was nonreactive with any Shigella polyvalent antisera.

Conclusion: This diarrheal outbreak appeared to be the result of shigellosis. Despite the fact that Shigella sonnei was the predominant organism isolated from patients, the causative agent of outbreak diarrhea remains obscure, since other Shigella species were also involved. The serologic testing supports this conclusion, as do the molecular patterns of the Shigella isolates. Having considered the time of investigation which was in the late stage of the outbreak, it was very likely that a collection of endemic and epidemic clinical samples was screened resulting in isolation of various Shigella species.

No MeSH data available.


Related in: MedlinePlus