Bioactivity and efficacy of a hyperimmune bovine colostrum product- Travelan, against shigellosis in a non-Human primate model (Macaca mulatta).

Infectious diarrhea is a World Health Organization public health priority area due to the lack of effective vaccines and an accelerating global antimicrobial resistance crisis. New strategies are urgently needed such as immunoprophylactic for prevention of diarrheal diseases. Hyperimmune bovine colostrum (HBC) is an established and effective prophylactic for infectious diarrhea. The commercial HBC product, Travelan® (Immuron Ltd, Australia) targets multiple strains of enterotoxigenic Escherichia coli (ETEC) is highly effective in preventing diarrhea in human clinical studies. Although Travelan® targets ETEC, preliminary studies suggested cross-reactivity with other Gram-negative enteric pathogens including Shigella and Salmonella species. For this study we selected an invasive diarrheal/dysentery-causing enteric pathogen, Shigella, to evaluate the effectiveness of Travelan®, both in vitro and in vivo. Here we demonstrate broad cross-reactivity of Travelan® with all four Shigella spp. (S. flexneri, S. sonnei, S. dysenteriae and S. boydii) and important virulence factor Shigella antigens. Naïve juvenile rhesus macaques (NJRM) were randomized, 8 dosed with Travelan® and 4 with a placebo intragastrically twice daily over 6 days. All NJRM were challenged with S. flexneri 2a strain 2457T on the 4th day of treatment and monitored for diarrheal symptoms. All placebo-treated NJRM displayed acute dysentery symptoms within 24-36 hours of challenge. Two Travelan®-treated NJRM displayed dysentery symptoms and six animals remained healthy and symptom-free post challenge; resulting in 75% efficacy of prevention of shigellosis (p = 0.014). These results strongly indicate that Travelan® is functionally cross-reactive and an effective prophylactic for shigellosis. This has positive implications for the prophylactic use of Travelan® for protection against both ETEC and Shigella spp. diarrheal infections. Future refinement and expansion of pathogens recognized by HBC including Travelan® could revolutionize current management of gastrointestinal infections and outbreaks in travelers' including military, peacekeepers, humanitarian workers and in populations living in endemic regions of the world.

Foodborne Outbreak of Extended Spectrum Beta-lactamase Producing Shigella sonnei Associated with Contaminated Spring Onions in the United Kingdom.

Globalization of the food supply chain has created conditions favorable for emergence and spread of multidrug-resistant (MDR) foodborne pathogens. In November 2021, the UK Health Security Agency detected an outbreak of 17 cases infected with the same strain of MDR extended spectrum beta-lactamase (ESBL)-producing Shigella sonnei. Phylogenetic analysis of whole-genome sequencing data revealed the outbreak was closely related to strains of S. sonnei isolated from travelers returning to the UK from Egypt. None of the outbreak cases reported travel and all 17 cases reported eating food from a restaurant/food outlet in the week prior to symptom onset, of which 11/17 (64.7%) ate at branches of the same national restaurant franchise. All 17 cases were adults and 14/17 (82.4%) were female. Ingredient-level analyses of the meals consumed by the cases identified spring onions as the common ingredient. Food chain investigations revealed that the spring onions served at the implicated restaurants could be traced back to a single Egyptian producer. The foodborne transmission of ESBL-producing bacteria is an emerging global health concern, and concerted action from all stakeholders is required to ensure an effective response to mitigate the risks to public health.

Outbreak of sexually transmitted, extensively drug-resistant Shigella sonnei in the UK, 2021-22: a descriptive epidemiological study.

BACKGROUND: Shigellosis, traditionally a foodborne and waterborne infection, causes substantial morbidity globally. It is now a leading cause of sexually transmitted gastroenteritis among gay, bisexual, and other men who have sex with men (MSM). We describe an ongoing outbreak of extensively drug-resistant (XDR) Shigella sonnei in the UK. METHODS: Routine laboratory surveillance (Second Generation Surveillance System, Gastrointestinal Data Warehouse) identified an exceedance of S sonnei clade 5 in England, first detected in September, 2021. Cases within this clade were subsequently reported from Scotland, Wales, and Northern Ireland. Confirmed cases in this outbreak were defined as individuals diagnosed with S sonnei clade 5 in the UK, with a specimen date between Sept 1, 2021, and Feb 9, 2022, who were genomically confirmed as part of a ten-single nucleotide polymorphism (SNP) linkage cluster. We used whole-genome sequencing with SNP typing to identify genomic clusters and antimicrobial-resistance determinants, analysing cases across the UK. We collected demographic, epidemiological, and clinical data from people infected with S sonnei clade 5 in England using questionnaires (standard and bespoke outbreak questionnaires). We used descriptive summary statistics to characterise cases. FINDINGS: 72 cases (70 [97%] male, median age 34 years [IQR 27-39]) belonging to the ten-SNP single linkage cluster of S sonnei clade 5 were identified between Sept 4, 2021, and Feb 9, 2022. Isolates were predominantly XDR, with 66 (92%) of 72 harbouring blaCTX-M-27, a plasmid-mediated gene for production of extended-spectrum ß-lactamases (ESBLs). Of 33 cases with clinical data, 19 (58%) received antibiotics and eight (24%) were hospitalised. 21 (78%) of 27 cases with completed bespoke outbreak questionnaires were HIV-negative MSM taking HIV pre-exposure prophylaxis (PrEP) who reported sexual contacts in the UK and Europe within the incubation period. INTERPRETATION: We highlight the rapid dissemination of XDR ESBL-producing S sonnei in sexual networks of MSM. We recommend strengthening shigella testing where clinically indicated, antimicrobial-resistance surveillance, and integrated health promotion messaging among all MSM, including PrEP users, to reduce the burden of shigellosis. FUNDING: National Institute for Health Research Health Protection Research Unit in Gastrointestinal Infections at the University of Liverpool in partnership with the UK Health Security Agency.

Azithromycin and Ciprofloxacin Treatment Outcomes During an Outbreak of Multidrug-Resistant Shigella sonnei Infections in a Retirement Community-Vermont, 2018.

BACKGROUND: In 2018, the Centers for Disease Control and Prevention and the Vermont Department of Health investigated an outbreak of multidrug-resistant Shigella sonnei infections in a retirement community that offered a continuum of care from independent living through skilled nursing care. The investigation identified 24 culture-confirmed cases. Isolates were resistant to trimethoprim-sulfamethoxazole, ampicillin, and ceftriaxone, and had decreased susceptibility to azithromycin and ciprofloxacin. METHODS: To evaluate clinical and microbiologic response, we reviewed inpatient and outpatient medical records for treatment outcomes among the 24 patients with culture-confirmed S. sonnei infection. We defined clinical failure as diarrhea (≥3 loose stools per day) for ≥1 day after treatment finished, and microbiologic failure as a stool culture that yielded S. sonnei after treatment finished. We used broth microdilution to perform antimicrobial susceptibility testing, and whole genome sequencing to identify resistance mechanisms. RESULTS: Isolates contained macrolide resistance genes mph(A) and erm(B) and had azithromycin minimum inhibitory concentrations above the Clinical and Laboratory Standards Institute epidemiological cutoff value of ≤16 µg/mL. Among 24 patients with culture-confirmed Shigella infection, 4 were treated with azithromycin; all had clinical treatment failure and 2 also had microbiologic treatment failure. Isolates were susceptible to ciprofloxacin but contained a gyrA mutation; 2 patients failed treatment with ciprofloxacin. CONCLUSIONS: These azithromycin treatment failures demonstrate the importance of clinical breakpoints to aid clinicians in identifying alternative treatment options for resistant strains. Additionally, these treatment failures highlight a need for comprehensive susceptibility testing and systematic outcome studies, particularly given the emergence of multidrug-resistant Shigella among an expanding range of patient populations.

Heterogeneity in enterotoxigenic Escherichia coli and shigella infections in children under 5 years of age from 11 African countries: a subnational approach quantifying risk, mortality, morbidity, and stunting.

BACKGROUND: Diarrhoea, a global cause of child mortality and morbidity, is linked to adverse consequences including childhood stunting and death from other diseases. Few studies explore how diarrhoeal mortality varies subnationally, especially by cause, which is important for targeting investments. Even fewer examine indirect effects of diarrhoeal morbidity on child mortality. We estimated the subnational distribution of mortality, morbidity, and childhood stunting attributable to enterotoxigenic Escherichia coli (ETEC) and shigella infection in children younger than 5 years from 11 eastern and central African countries. These pathogens are leading causes of diarrhoea in young children and have been linked to increased childhood stunting. METHODS: We combined proxy indicators of morbidity and mortality risk from the most recent Demographic and Health Surveys with published relative risks to estimate the potential distribution of diarrhoeal disease risk. To estimate subnational burden, we used country-specific or WHO region-specific morbidity and mortality estimates and distributed them subnationally by three indices that integrate relevant individual characteristics (ie, underweight, probability of receiving oral rehydration treatment of diarrhoea, and receiving vitamin A supplementation) and household characteristics (ie, type of drinking water and sanitation facilities). FINDINGS: Characterising ETEC and shigella subnational estimates of indirect morbidity (infection-attributable stunting) and indirect mortality (stunting-related deaths from other infectious diseases) identified high-risk areas that could be missed by traditional metrics. Burundi and Democratic Republic of the Congo had the highest ETEC-associated and shigella-associated mortality and stunting rates. Mozambique, Democratic Republic of the Congo, and Zimbabwe had the greatest subnational heterogeneity in most ETEC and shigella mortality measures. Inclusion of indirect ETEC and shigella mortality in burden estimates resulted in a 20-30% increase in total ETEC and shigella mortality rates in some subnational areas. INTERPRETATION: Understanding the indirect mortality and morbidity of diarrhoeal pathogens on a subnational level will strengthen disease control strategies and could have important implications for the relative impact and cost-effectiveness of new enteric vaccines. Because our methods rely on publicly available data, they could be employed for national planning. FUNDING: Bill & Melinda Gates Foundation.

WHO consultation on ETEC and Shigella burden of disease, Geneva, 6-7th April 2017: Meeting report.

According to the 2015 Global Burden of Disease Study, diarrhea ranked ninth among causes of death for all ages, and fourth among children under 5 years old, accounting for an estimated 499,000 deaths in this young age group. It was also the second most common cause of years lived with disability (2.39 billion YLDs). The goal of the WHO/UNICEF Integrated Global Action Plan for the Prevention and Control of Pneumonia and Diarrhea (GAPPD) is to reduce deaths from diarrhea in children under 5 years of age to less than 1 per 1000 live births, by 2025. Development of new and improved vaccines against diarrheal infections is a fundamental element of the strategy towards achieving this goal. Enterotoxigenic Escherichia coli (ETEC) and Shigella are enteropathogens that cause significant global mortality and morbidity, particularly in low- and middle-income countries. In 2016, WHO's Product Development for Vaccines Advisory Committee (PDVAC) recommended that the WHO's Initiative for Vaccine Research (IVR) engage in this area, based on PDVAC's criteria of prioritizing the development of vaccines against pathogens that will address a major unmet public health need, and for which clinical candidates with a good probability of technical success are in the pipeline. As a first step, WHO's IVR convened global subject matter experts to discuss the current global ETEC and Shigella disease burden estimates, including the current understanding of the long-term indirect effects of ETEC and Shigella infection, and how these data may affect future decision making on vaccine development for both pathogens. The available global burden estimates for ETEC and Shigella differ with respect to the relative importance of these two pathogens. The mortality estimates vary between iterations published by the same group, as well as between estimates of different groups, although the uncertainty intervals are broad and overlapping. These variances are attributable to differences in the data available and incorporated in the models; the methods used to detect the pathogens; the modelling methodologies; and, to actual changes in the total number of diarrheal deaths over time. The changes in the most recently reported mortality estimates for these pathogens, as compared to previous iterations, has led to debate as to whether investment in development of stand-alone vaccines, rather than combined vaccines, is warranted from cost-effectiveness and vaccine impact perspectives. Further work will be needed to understand better the variances and uncertainties in the reported mortality estimates to support investment decision making, and ultimately policy recommendations for vaccine use. In addition, a comprehensive assessment of the value proposition for vaccines against these pathogens is needed and will be strengthened if the long-term health consequences associated with diarrhea and dysentery due to these pathogens are better defined.

Prevalence and antibiotic susceptibility patterns of Shigella and Salmonella among children aged below five years with Diarrhoea attending Nigist Eleni Mohammed memorial hospital, South Ethiopia.

BACKGROUND: Diarrhoeal disease is the second leading cause of death among children aged below 5 years. Even though, both preventable and treatable diseases, globally there are nearly 1.7 billion cases of childhood diarrhoeal disease and responsible for killing around 525,000 children every year. Shigella and Salmonella species were the leading cause of etiologic agents for diarrhoea associated deaths. The aim of this study was to determine the prevalence and antibiotic susceptibility patterns of Shigella and Salmonella isolated from children aged below 5 years with diarrhoea attending Nigist Eleni Mohammed Memorial Hospital, Hossana, South Ethiopia. METHODS: A cross sectional study was conducted from June 02 to September 24, 2017. Two hundred four children aged below 5 years with diarrhoea were enrolled consecutively using convenience sampling technique. Stool specimens were processed in accordance with the standard bacteriological methods and antibiotic susceptibility pattern of the isolates was determined using disc diffusion method. Data were analyzed using SPSS version 20. RESULTS: Out of the 204 children aged below 5 years with diarrhoeal disease 19/204 (9.3%, [95%CI, 5.7-13.7%]) of them were positive for bacterial growth, of which 17/204(8.3%) were Shigella species and 2/204(1%) were Salmonella species. Both Shigella and Salmonella isolates were 100% susceptible to norfloxacin, nalidixic acid and kanamycin. However, isolates of Shigella showed 100, 76.5 and 64.7% resistance to ampicillin, gentamicin and cotrimoxazole respectively while Salmonella species were highly resistant to ampicillin and gentamicin (100% each). CONCLUSIONS: Salmonella and Shigella species is prevalent in the current study area. Among the tested antibiotics, norfloxacin, nalidixic acid and kanamycin were found to be most effective for both isolates. Both species are developing resistance to the commonly prescribed antibiotic. Therefore, culture based bacterial species identification and antimicrobial susceptibility testing services are strongly recommended to avoid empirical treatment in the study area.

Antibiotic resistance and molecular characterization of shigella isolates recovered from children aged less than 5 years in Manhiça, Southern Mozambique.

The objective of this study was to assess antibiotic resistance and the molecular epidemiology of shigella isolates from a case-control study of diarrhoea, conducted from 2007 to 2012 in children aged less than 5 years in Manhiça district, southern Mozambique. All isolates were tested for antimicrobial susceptibility using the disc diffusion method. Polymerase chain reaction was used to detect different molecular mechanisms of antibiotic resistance. Serotyping was performed using specific antisera. The clonal relationship of Shigella flexneri and Shigella sonnei was assessed by pulsed-field gel electrophoresis (PFGE). Of the 67 shigella isolates analysed, 59 were diarrhoeal cases and eight were controls. S. flexneri (70.1%; 47/67) was the most common species, followed by S. sonnei (23.9%; 16/67). The most prevalent S. flexneri serotypes were 2a (38.3%; 18/47), 6 (19.2%; 9/47) and 1b (14.9%; 7/47). High rates of antimicrobial resistance were observed for trimethoprim-sulfametoxazole (92.5%; 62/67), tetracycline (68.7%; 46/67), chloramphenicol (53.7%; 36/67) and ampicillin (50.7%; 34/67). Multi-drug resistance (MDR) was present in 55.2% (37/67) of the isolates and was associated with a case fatality rate of 8.1% (3/37). PFGE revealed 22 clones (16 S. flexneri and 6 S. sonnei), among which P1 (31.9%; 15/47), P9 (17%; 8/47) and P2 (10.6%; 5/47) were the most prevalent clones of S. flexneri. In conclusion, S. flexneri was the most prevalent species, with MDR isolates mainly belonging to three specific clones (P1, P9 and P2). The case fatality rate observed among MDR isolates is a matter of concern, indicating the need for appropriate treatment.

Recent epidemiology of sexually transmissible enteric infections in men who have sex with men.

PURPOSE OF REVIEW: Sexual transmission of enteric pathogens in men who have sex with men (MSM) has been described since the 1970s. Recently, an increasing number of enteric infection outbreaks have been reported in MSM. This article summarizes recent outbreaks and discusses the key issues for prevention and control. RECENT FINDINGS: Sexually transmissible enteric infections (STEIs) can spread rapidly and internationally within highly connected MSM populations and are often associated with antimicrobial resistance (AMR). The infections often cluster in high-risk groups of HIV-positive MSM who are more likely to engage in diverse sexual practices and chemsex, and to have multiple other sexually transmitted infections (STIs). SUMMARY: The roles of asymptomatic and/or persistent infection and other contextual factors in STEI transmission are not well described. STEI-associated AMR is increasing and has potential to spread rapidly in MSM, warranting further public health attention. A better understanding of the factors associated with sexual transmission will enable the development of more effective control measures. A holistic approach that promotes health and wellbeing as well as infection prevention and management is needed.

Shigella species epidemiology and antimicrobial susceptibility: the implications of emerging azithromycin resistance for guiding treatment, guidelines and breakpoints.

OBJECTIVES: To examine antimicrobial susceptibility patterns and predictors of resistance among Shigella isolates in New South Wales (NSW), Australia during 2013-14 with emphasis on azithromycin. METHODS: Cross-sectional analysis of all shigellosis cases (160) notified to public health authorities in NSW, Australia was performed. RESULTS: Among 160 Shigella isolates tested, 139 (86.9%) were susceptible to azithromycin, 104 (65.0%) to ciprofloxacin and 38 (23.7%) to co-trimoxazole. Ciprofloxacin resistance was 1.9 times more common in infections acquired in Australia compared with those acquired overseas, while azithromycin resistance was 8.5 times more common in males. CONCLUSIONS: We recommend ongoing reconsideration of guidelines for the treatment of shigellosis based on emerging resistance patterns. First-line therapy may need to be reconsidered based on local resistance rates due to common resistance to co-trimoxazole and ciprofloxacin. We recommend culture and susceptibility testing for suspected and proven shigellosis. Azithromycin susceptibility breakpoints for Shigella species may need to be species specific.

Identification and antimicrobial resistance patterns of bacterial enteropathogens from children aged 0-59 months at the University Teaching Hospital, Lusaka, Zambia: a prospective cross sectional study.

BACKGROUND: Bacterial diarrhoeal disease is among the most common causes of mortality and morbidity in children 0-59 months at the University Teaching Hospital in Lusaka, Zambia. However, most cases are treated empirically without the knowledge of aetiological agents or antimicrobial susceptibility patterns. The aim of this study was, therefore, to identify bacterial causes of diarrhoea and determine their antimicrobial susceptibility patterns in stool specimens obtained from the children at the hospital. METHODS: This hospital-based cross-sectional study involved children aged 0-59 months presenting with diarrhoea at paediatrics wards at the University Teaching Hospital in Lusaka, Zambia, from January to May 2016. Stool samples were cultured on standard media for enteropathogenic bacteria, and identified further by biochemical tests. Multiplex polymerase chain reaction was used for characterization of diarrhoeagenic Escherichia coli strains. Antimicrobial susceptibility testing was performed on antibiotics that are commonly prescribed at the hospital using the Kirby-Bauer disc diffusion method, which was performed using the Clinical Laboratory Standards International guidelines. RESULTS: Of the 271 stool samples analysed Vibrio cholerae 01 subtype and Ogawa serotype was the most commonly detected pathogen (40.8%), followed by Salmonella species (25.5%), diarrhoeagenic Escherichia coli (18%), Shigella species (14.4%) and Campylobacter species (3.5%). The majority of the bacterial pathogens were resistant to two or more drugs tested, with ampicillin and co-trimoxazole being the most ineffective drugs. All diarrhoeagenic Escherichia coli isolates were extended spectrum ß-lactamase producers. CONCLUSION: Five different groups of bacterial pathogens were isolated from the stool specimens, and the majority of these organisms were multidrug resistant. These data calls for urgent revision of the current empiric treatment of diarrhoea in children using ampicillin and co-trimoxazole, and emphasizes the need for continuous antimicrobial surveillance as well as the implementation of prevention programmes for childhood diarrhoea.

South Asia as a Reservoir for the Global Spread of Ciprofloxacin-Resistant Shigella sonnei: A Cross-Sectional Study.

BACKGROUND: Antimicrobial resistance is a major issue in the Shigellae, particularly as a specific multidrug-resistant (MDR) lineage of Shigella sonnei (lineage III) is becoming globally dominant. Ciprofloxacin is a recommended treatment for Shigella infections. However, ciprofloxacin-resistant S. sonnei are being increasingly isolated in Asia and sporadically reported on other continents. We hypothesized that Asia is a primary hub for the recent international spread of ciprofloxacin-resistant S. sonnei. METHODS AND FINDINGS: We performed whole-genome sequencing on a collection of 60 contemporaneous ciprofloxacin-resistant S. sonnei isolated in four countries within Asia (Vietnam, n = 11; Bhutan, n = 12; Thailand, n = 1; Cambodia, n = 1) and two outside of Asia (Australia, n = 19; Ireland, n = 16). We reconstructed the recent evolutionary history of these organisms and combined these data with their geographical location of isolation. Placing these sequences into a global phylogeny, we found that all ciprofloxacin-resistant S. sonnei formed a single clade within a Central Asian expansion of lineage III. Furthermore, our data show that resistance to ciprofloxacin within S. sonnei may be globally attributed to a single clonal emergence event, encompassing sequential gyrA-S83L, parC-S80I, and gyrA-D87G mutations. Geographical data predict that South Asia is the likely primary source of these organisms, which are being regularly exported across Asia and intercontinentally into Australia, the United States and Europe. Our analysis was limited by the number of S. sonnei sequences available from diverse geographical areas and time periods, and we cannot discount the potential existence of other unsampled reservoir populations of antimicrobial-resistant S. sonnei. CONCLUSIONS: This study suggests that a single clone, which is widespread in South Asia, is likely driving the current intercontinental surge of ciprofloxacin-resistant S. sonnei and is capable of establishing endemic transmission in new locations. Despite being limited in geographical scope, our work has major implications for understanding the international transfer of antimicrobial-resistant pathogens, with S. sonnei acting as a tractable model for studying how antimicrobial-resistant Gram-negative bacteria spread globally.

Characteristics of bacterial acute diarrhea among women.

OBJECTIVE: To describe the clinical and microbiological characteristics of women presenting with acute gastroenteritis due to infection with Salmonella spp. or Shigella spp. METHODS: A cross-sectional retrospective study was conducted using data for patients with specimens positive for Shigella spp. and Salmonella spp. attending two major women's hospitals in Porto Alegre, Brazil, between January 2003 and July 2014. Women were included if they had symptoms compatible with bacterial acute diarrhea. Isolates were evaluated to determine antimicrobial susceptibility and patient clinical profile. RESULTS: Among 45 eligible patients, Salmonella spp. was identified in 32 (71%) and Shigella spp. in 13 (29%). The highest antimicrobial sensitivity rates were observed for ciprofloxacin and ceftriaxone (n=44, 98% for both) whereas the greatest resistance rate was seen for ampicillin (n=20, 44%). Seven (16%) of the women were pregnant. CONCLUSION: Ciprofloxacin, ceftriaxone, and sulfamethoxazole/trimethoprim are suitable choices for the treatment of bacterial acute diarrhea. However, the maternal and fetal safety profile of prescribed medications should be considered when treating pregnant patients.

Shigellosis in Subjects with Traveler's Diarrhea Versus Domestically Acquired Diarrhea: Implications for Antimicrobial Therapy and Human Immunodeficiency Virus Surveillance.

An increase of sexually transmitted shigellosis is currently being reported in developed countries. In addition, travel-related shigellosis can introduce resistant strains that could be disseminated within this new scenario. Epidemiological features and antimicrobial susceptibility of shigellosis depending on where infection was acquired were investigated. From 2008 to 2013, subjects with shigellosis were studied. Patients were classified according to acquisition of Shigella as traveler's diarrhea (TD) or domestically acquired diarrhea (DAD). Ninety cases of shigellosis were identified: 76 corresponding to the TD group and 14 to the DAD group. In the DAD group, most of patients were human immunodeficiency virus (HIV)-positive men who have sex with men (MSM), being shigellosis associated to male sex (P = 0.007) and HIV infection (P < 0.0001). S. sonnei (47.8%) and S. flexneri (42.2%) were the predominant species. The highest resistance was detected for trimethoprim/sulfamethoxazole (SXT) (81.8%), followed by ampicillin (AMP) (37.8%) and ciprofloxacin (CIP) (23.3%). Resistant Shigella strains were more frequent in subjects with TD than those with DAD, although only for CIP the difference was significant (P = 0.034). Continuous monitoring of patients with shigellosis is necessary to control the spread of resistant Shigella strains and for effective therapy. Men with shigellosis who have not traveled to an endemic area should be screened for HIV infection.

Molecular characterization of Shigella spp. from patients in Gabon 2011-2013.

BACKGROUND: Shigella spp. dysentery is widespread in developing countries; the incidence is particularly high in children between 1-2 years of age. In sub-Saharan Africa, there is a paucity of epidemiological data on Shigella spp., with possible negative consequences for recognition and correct treatment choice for this life-threatening bacterial infection. We therefore characterized Shigella spp. isolates from Gabon. METHODS: The antimicrobial resistance, virulence factors, genotypes and mobile genetic elements of Shigella isolates (29 S. flexneri; 5 S. boydii; 3 S. sonnei) from a retrospective strain collection were analyzed. RESULTS: High resistance rates were found for gentamicin and tetracycline (100%, 37/37), cotrimoxazole (92%, 34/37) and ampicillin (84%, 31/37). All isolate harbored ial and ipaH; no isolate produced Shiga toxins (stx1/2); enterotoxins (set1A/B) were only found in S. flexneri (n=19). Multilocus sequence types (MLST) clustered with global clones. A high prevalence of atypical class 1 integrons harboring blaOXA30 and aadA1 were detected in S. flexneri, while all S. sonnei carried class 2 integrons. CONCLUSIONS: There is a strong link of Gabonese Shigella spp. isolates with pandemic lineages as they cluster with major global clones and frequently carry atypical class 1 integrons which are frequently reported in Shigella spp. from Asia.

Changing trends in the prevalence of Shigella species: emergence of multi-drug resistant Shigella sonnei biotype g in Bangladesh.

Shigellosis, caused by Shigella species, is a major public health problem in Bangladesh. To determine the prevalence and distribution of different Shigella species, we analyzed 10,827 Shigella isolates from patients between 2001 and 2011. S. flexneri was the predominant species isolated throughout the period. However, the prevalence of S. flexneri decreased from 65.7% in 2001 to 47% in 2011, whereas the prevalence of S. sonnei increased from 7.2% in 2001 to 25% in 2011. S. boydii and S. dysenteriae accounted for 17.3% and 7.7% of the isolates respectively throughout the period. Of 200 randomly selected S. sonnei isolates for extensive characterization, biotype g strains were predominant (95%) followed by biotype a (5%). Resistance to commonly used antibiotics including trimethoprim-sulfamethoxazole, nalidixic acid, ciprofloxacin, mecillinam and ampicillin was 89.5%, 86.5%, 17%, 10.5%, and 9.5%, respectively. All isolates were susceptible to ceftriaxone, cefotaxime, ceftazidime and imipenem. Ninety-eight percent of the strains had integrons belonging to class 1, 2 or both. The class 1 integron contained only dfrA5 gene, whereas among class 2 integron, 16% contained dhfrAI-sat1-aadA1-orfX gene cassettes and 84% harbored dhfrA1-sat2 gene cassettes. Plasmids of ∼5, ∼1.8 and ∼1.4 MDa in size were found in 92% of the strains, whereas only 33% of the strains carried the 120 MDa plasmid. PFGE analysis showed that strains having different integron patterns belonged to different clusters. These results show a changing trend in the prevalence of Shigella species with the emergence of multidrug resistant S. sonnei. Although S. flexneri continues to be the predominant species albeit with reduced prevalence, S. sonnei has emerged as the second most prevalent species replacing the earlier dominance by S. boydii and S. dysenteriae in Bangladesh.

Correlation analysis for the attack of bacillary dysentery and meteorological factors based on the Chinese medicine theory of Yunqi and the medical-meteorological forecast model.

OBJECTIVE: To explore the impact of meteorological factors on the outbreak of bacillary dysentery, so as to provide suggestions for disease prevention. METHODS: Based on the Chinese medicine theory of Yunqi, the descriptive statistics, single-factor correlation analysis and back-propagation artificial neural net-work were conducted using data on five basic meteorological factors and data on incidence of bacillary dysentery in Beijing, China, for the period 1970-2004. RESULTS: The incidence of bacillary dysentery showed significant positive correlation relationship with the precipitation, relative humidity, vapor pressure, and temperature, respectively. The incidence of bacillary dysentery showed a negatively correlated relationship with the wind speed and the change trend of average wind speed. The results of medical-meteorological forecast model showed a relatively high accuracy rate. CONCLUSIONS: There is a close relationship between the meteorological factors and the incidence of bacillary dysentery, but the contributions of which to the onset of bacillary dysentery are different to each other.

Clinical characteristics and antibiotic resistance of Shigella gastroenteritis in Ankara, Turkey between 2003 and 2009, and comparison with previous reports.

OBJECTIVES: The aim of this study was to define the epidemiological, clinical, and antibiotic susceptibility patterns of Shigella gastroenteritis cases occurring during the years 2003-2009 and to compare results with those of the years 1987-2002. METHODS: A hospital-based study was conducted over a 22-year period. All 238 Shigella strains isolated between 2003 and 2009 were compared to 618 isolates from the period 1987-1994 and 218 Shigella strains isolated during 1995-2002 with regard to antimicrobial resistance patterns and patient clinical characteristics. RESULTS: The predominant species during all periods was Shigella sonnei, with an increasing predominance across the periods (64.0%, 71.5%, and 87.8%, respectively; p<0.001). Neither the prevalence of bloody diarrhea nor other clinical characteristics changed across the study periods, except for the prevalence of dehydration, which increased (11.0%, 20.6%, and 28.6%, respectively; p<0.001). During the period 2003-2009, 69.9% of Shigella were resistant to trimethoprim/sulfamethoxazole, 35.8% to ampicillin, and 4.7% to nalidixic acid. No case resistant to ciprofloxacin was detected. Multidrug resistance was also found to be similar in the last two periods (24.0% vs. 28.1%, respectively). CONCLUSIONS: There was both a microbiological and a clinical change in childhood Shigella gastroenteritis cases over the 22 years. The antibiotic resistance pattern appears to have remained stable over the last two periods. There is a need to re-examine the criteria and clinical management guidelines for suspected shigellosis cases.

Ciprofloxacin-resistant Shigella sonnei among men who have sex with men, Canada, 2010.

In 2010, we observed isolates with matching pulsed-field gel electrophoresis patterns from 13 cases of ciprofloxacin-resistant Shigella sonnei in Montréal. We report on the emergence of this resistance type and a study of resistance mechanisms. The investigation suggested local transmission among men who have sex with men associated with sex venues.