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Epidemic cholera has been registered several times within recent years in Iran. The dominant genotype was Ogawa until 2011, but this gradually changed to Inaba. However, in 2015, the re-appearance of a previous Ogawa genotype was detected by the Iranian CDC. This raised worries because no evidence was found for its origin abroad. The aim of the pre...
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... different outbreaks in the last year of the study period occurred at least 3 months apart. In the first outbreak, in late spring, 45 Ogawa specimens were detected. They were detected in Ahvaz and its suburb (southwest Iran), although one case of this type was reported in Semnan, a city in central northern Iran (Fig. 1). The second outbreak was observed in the autumn, in a few cities, and comprised 23 cases. This time, all specimens were identified as Inaba type. These strains have been isolated from the following area: central cities (Arak, Qom, Karaj and Tehran), northern part (Golestan), Mashhad (a tourist town in the northeast), Gonabad (an ...
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... were identified as Inaba type. These strains have been isolated from the following area: central cities (Arak, Qom, Karaj and Tehran), northern part (Golestan), Mashhad (a tourist town in the northeast), Gonabad (an eastern city near the Afghan border), Bushahr (a port town in the south of Iran) and Ahvaz (a city in southwest Iran) ( Table 2 and Fig. ...
Context 3
... different outbreaks in the last year of the study period occurred at least 3 months apart. In the first outbreak, in late spring, 45 Ogawa specimens were detected. They were detected in Ahvaz and its suburb (southwest Iran), although one case of this type was reported in Semnan, a city in central northern Iran (Fig. 1). The second outbreak was observed in the autumn, in a few cities, and comprised 23 cases. This time, all specimens were identified as Inaba type. These strains have been isolated from the following area: central cities (Arak, Qom, Karaj and Tehran), northern part (Golestan), Mashhad (a tourist town in the northeast), Gonabad (an ...
Context 4
... were identified as Inaba type. These strains have been isolated from the following area: central cities (Arak, Qom, Karaj and Tehran), northern part (Golestan), Mashhad (a tourist town in the northeast), Gonabad (an eastern city near the Afghan border), Bushahr (a port town in the south of Iran) and Ahvaz (a city in southwest Iran) ( Table 2 and Fig. ...
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Cholera, caused by the pathogenic Vibrio cholerae bacteria, remains a severe public health threat. Although a lot of emphasis has been placed on the population-level spread of the disease, the infection itself starts within the body. As such, we formulated a multi-scale model that explicitly connects the within-host and between-host dynamics of the...
Citations
... As an endemic disease, cholera outbreaks are annually reported from Iran; However, cross-border cases from neighbor countries including Pakistan, Afghanistan and Iraq, are also observed in some provinces. To our knowledge, approximately 400 cholera cases have been reported from Iran during 2012-2016 (mainly May-November) [41,42]. This prompted us to undertake the genetic characterization of recent cholera outbreaks and better understanding of endemic cholera. ...
Vibrio cholerae, as a natural inhabitant of the marine environment is among the world-leading causes of diarrheal diseases. The present study aimed to investigate the genetic relatedness of Iran 2012–2016 V. cholerae outbreaks with 7th pandemic cholera and to further characterize the non-ST69/non-ST75 sequence types strains by whole-genome sequencing (WGS).
Twenty V. cholerae isolates related to 2012, 2013, 2015 and 2016 cholera outbreaks were studied by two genotyping methods – Pulsed-field Gel Electrophoresis (PFGE) and Multi-locus Sequence Typing (MLST)–and by antimicrobial susceptibility testing. Seven sequence types (STs) and sixteen pulsotypes were detected. Sequence type 69 was the most abundant ST confirming that most (65%, 13/20) of the studied isolates collected in Iran between 2012 and 2016 belonged to the 7th pandemic clone. All these ST69 isolates (except two) exhibited similar pulsotypes. ST75 was the second most abundant ST. It was identified in 2015 and 2016. ST438, ST178, ST579 and STs of 983 and 984 (as newfound STs) each were only detected in one isolate. All strains collected in 2016 appeared as distinct STs and pulsotypes indicative of probable different originations. All ST69 strains were resistant to nalidixic acid. Moreover, resistance to nalidixic acid, trimethoprim-sulfamethoxazole and tetracycline was only observed in strains of ST69. These properties propose the ST69 as a unique genotype derived from a separate lineage with distinct resistance properties. The circulation of V. cholerae ST69 and its traits in recent years in Iran proposes the 7th pandemic strains as the ongoing causes of cholera outbreaks in this country, although the role of ST75 as the probable upcoming dominant ST should not be ignored.
Genomic analysis of non-ST69/non-ST75 strains in this study showed ST579 is the most similar ST type to 7th pandemic sequence types, due to the presence of wild type-El Tor sequences of tcpA and VC-1319, VC-1320, VC-1577, VC-1578 genes (responsible for polymyxin resistance in El Tor biotype), the traits of rstC of RS1 phage in one strain of this ST type and the presence of VPI-1 and VSP-I islands in ST579 and ST178 strains. In silico analysis showed no significant presence of resistance genes/cassettes/plasmids within non-ST69/non-ST75 strains genomes. Overall, these data indicate the higher susceptibility of V. cholerae non-ST69/non-ST75 strains in comparison with more ubiquitous and more circulating ST69 and ST75 strains.
In conclusion, the occurrence of small outbreaks and sporadic cholera cases due to V. cholerae ST69 in recent years in Iran shows the 7th pandemic strains as the persistent causes of cholera outbreaks in this country, although the role of ST75 as the second most contributed ST should not be ignored. The occurrence of non-ST69/non-ST75 sequence types with some virulence factors characteristics in border provinces in recent years is noteworthy, and further studies together with surveillance efforts are expected to determine their likely route of transport.
Cholera caused by toxigenic Vibrio cholerae is a major public health problem in many developing countries, where outbreaks and sporadic infections occur at regular intervals. WHO has registered 499,447 cases, including 2990 deaths with case fatality rate of 0.6% in 2018 [1]. The disease is characterized by profuse watery diarrhea that rapidly leads to dehydration, and death occurs in 50–70% of untreated patients.
