A50 The emergence of G8P[8] rotavirus group A across Vietnam

Group A rotaviruses (RoV) are highly transmissible, globally ubiquitous, and are the principal cause of acute gastroenteritis in children. RoV are non-enveloped double-stranded RNA viruses comprised of 11 independent gene segments, encoding six structural proteins (VP1–VP4, VP6 and VP7) and five nonstructural proteins (NSP1– NSP5/6). Reassortment of viral segments can occur when a single cell is co-infected with two or more viruses, yielding mixed progeny with gene segments derived from multiple parental strains. Within a hospital-based study conducted to determine the etiology of diarrhea in five provincial hospitals located across Vietnam from 2012 to 2015, we detect RoV in 50.2% of all cases (678 RoV-positive/1,350 diarrhea cases)

The emergence of G8P[8] rotavirus group A across Vietnam.

Group A rotaviruses (RoV) are highly transmissible, globally ubiquitous, and are the principal cause of acute gastroenteritis in children. RoV are non-enveloped double-stranded RNA viruses comprised of 11 independent gene segments, encoding six structural proteins (VP1–VP4, VP6 and VP7) and five nonstructural proteins (NSP1– NSP5/6). Reassortment of viral segments can occur when a single cell is co-infected with two or more viruses, yielding mixed progeny with gene segments derived from multiple parental strains. Within a hospital-based study conducted to determine the etiology of diarrhea in five provincial hospitals located across Vietnam from 2012 to 2015, we detect RoV in 50.2% of all cases (678 RoV-positive/1,350 diarrhea cases)

The emergence of G8P[8] rotavirus group A across Vietnam.

Group A rotaviruses (RoV) are highly transmissible, globally ubiquitous, and are the principal cause of acute gastroenteritis in children. RoV are non-enveloped double-stranded RNA viruses comprised of 11 independent gene segments, encoding six structural proteins (VP1–VP4, VP6 and VP7) and five nonstructural proteins (NSP1– NSP5/6). Reassortment of viral segments can occur when a single cell is co-infected with two or more viruses, yielding mixed progeny with gene segments derived from multiple parental strains. Within a hospital-based study conducted to determine the etiology of diarrhea in five provincial hospitals located across Vietnam from 2012 to 2015, we detect RoV in 50.2% of all cases (678 RoV-positive/1,350 diarrhea cases)

An epidemiological investigation of Campylobacter in pig and poultry farms in the Mekong delta of Vietnam.

Campylobacter are zoonotic pathogens commonly associated with gastroenteritis. To assess the relevance of Campylobacter in Vietnam, an economically transitioning country in SE Asia, we conducted a survey of 343 pig and poultry farms in the Mekong delta, a region characterized by mixed species farming with limited biosecurity. The animal-level prevalence of Campylobacter was 31·9%, 23·9% and 53·7% for chickens, ducks and pigs, respectively. C. jejuni was predominant in all three host species, with the highest prevalence in pigs in high-density production areas. Campylobacter isolates demonstrated high levels of antimicrobial resistance (21% and 100% resistance against ciprofloxacin and erythromycin, respectively). Multilocus sequence type genotyping showed a high level of genetic diversity within C. jejuni, and predicted C. coli inter-species transmission. We suggest that on-going intensification of animal production systems, limited biosecurity, and increased urbanization in Vietnam is likely to result in Campylobacter becoming an increasingly significant cause of human diarrhoeal infections in coming years

A28 Frequent co-infection among human group a rotaviruses in Thailand

Rotavirus (RoV) is a non-enveloped dsRNA virus in the Reoviridae family, with a 18.5-kb genome of 11 segments encoding six structural (VP1–4, VP6 and VP7) and five or six non-structural proteins (NSP1-NSP5/6). Reassortment between human and/or animal RoVs plays an important role in the generation of genetic diversity in these viruses, and is presumed to result from co-infection in human or animal reservoirs. However, coinfection with heterologous RoV has rarely been documented, in part due to inadequate detection methods and a lack of largescale genomic investigations. Despite the availability of an efficacious vaccine, the burden of rotaviral diarrhea remains high in many developing countries, with rotavirus infection detected in 40–50% of all pediatric patients hospitalized with diarrhea. In addition to its cost, reduced vaccine effectiveness in developing country settings has contributed to its low uptake and the lack of government support for vaccination programs across Southeast Asia. The genetics and dynamics of rotavirus (RoV) have rarely been systematically investigated in these settings

Frequent co-infection among human group a rotaviruses in Thailand.

Rotavirus (RoV) is a non-enveloped dsRNA virus in the Reoviridae family, with a 18.5-kb genome of 11 segments encoding six structural (VP1–4, VP6 and VP7) and five or six non-structural proteins (NSP1-NSP5/6). Reassortment between human and/or animal RoVs plays an important role in the generation of genetic diversity in these viruses, and is presumed to result from co-infection in human or animal reservoirs. However, coinfection with heterologous RoV has rarely been documented, in part due to inadequate detection methods and a lack of largescale genomic investigations. Despite the availability of an efficacious vaccine, the burden of rotaviral diarrhea remains high in many developing countries, with rotavirus infection detected in 40–50% of all pediatric patients hospitalized with diarrhea. In addition to its cost, reduced vaccine effectiveness in developing country settings has contributed to its low uptake and the lack of government support for vaccination programs across Southeast Asia. The genetics and dynamics of rotavirus (RoV) have rarely been systematically investigated in these settings

Frequent co-infection among human group a rotaviruses in Thailand.

Rotavirus (RoV) is a non-enveloped dsRNA virus in the Reoviridae family, with a 18.5-kb genome of 11 segments encoding six structural (VP1–4, VP6 and VP7) and five or six non-structural proteins (NSP1-NSP5/6). Reassortment between human and/or animal RoVs plays an important role in the generation of genetic diversity in these viruses, and is presumed to result from co-infection in human or animal reservoirs. However, coinfection with heterologous RoV has rarely been documented, in part due to inadequate detection methods and a lack of largescale genomic investigations. Despite the availability of an efficacious vaccine, the burden of rotaviral diarrhea remains high in many developing countries, with rotavirus infection detected in 40–50% of all pediatric patients hospitalized with diarrhea. In addition to its cost, reduced vaccine effectiveness in developing country settings has contributed to its low uptake and the lack of government support for vaccination programs across Southeast Asia. The genetics and dynamics of rotavirus (RoV) have rarely been systematically investigated in these settings

Fitness benefits in fluoroquinolone-resistant Salmonella Typhi in the absence of antimicrobial pressure

Fluoroquinolones (FQ) are the recommended antimicrobial treatment for typhoid, a severe systemic infection caused by the bacterium Salmonella enterica serovar Typhi. FQ-resistance mutations in S. Typhi have become common, hindering treatment and control efforts. Using in vitro competition experiments, we assayed the fitness of eleven isogenic S. Typhi strains with resistance mutations in the FQ target genes, gyrA and parC. In the absence of antimicrobial pressure, 6 out of 11 mutants carried a selective advantage over the antimicrobial-sensitive parent strain, indicating that FQ resistance in S. Typhi is not typically associated with fitness costs. Double-mutants exhibited higher than expected fitness as a result of synergistic epistasis, signifying that epistasis may be a critical factor in the evolution and molecular epidemiology of S. Typhi. Our findings have important implications for the management of drug-resistant S. Typhi, suggesting that FQ-resistant strains would be naturally maintained even if fluoroquinolone use were reduced

Novel porcine-like human G26P[19] rotavirus identified in hospitalized paediatric diarrhea patients in Ho Chi Minh City, Vietnam

During a hospital-based diarrhoeal disease study conducted in Ho Chi Minh City, Vietnam from 2009 to 2010, we identified four symptomatic children infected with G26P[19] rotavirus (RV)-an atypical variant that has not previously been reported in human gastroenteritis. To determine the genetic structure and investigate the origin of this G26P[19] strain, the whole genome of a representative example was characterized, revealing a novel genome constellation: G26-P[19]-I5-R1-C1-M1-A8-N1-T1-E1-H1. The genome segments were most closely related to porcine (VP7, VP4, VP6 and NSP1) and Wa-like porcine RVs (VP1-3 and NSP2-5). We proposed that this G26P[19] strain was the product of zoonotic transmission coupled with one or more reassortment events occurring in human and/or animal reservoirs. The identification of such strains has potential implications for vaccine efficacy in south-east Asia, and outlines the utility of whole-genome sequencing for studying RV diversity and zoonotic potential during disease surveillance