MDPI AG Acta Medica Okayama 2076-2607 14 7 2026 Upregulation of the Outer Membrane Protein OmpV and Its Role in Polymyxin B Stress Adaptation in Vibrio mimicus 1527 EN Shin-ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yuta Onodera Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shunki Annoi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Basilua Andre Muzembo Research Center for Intestinal Health Science, Okayama University Daisuke Imamura Research Institute of Nursing Care for People and Community, University of Hyogo OmpV is an outer membrane protein found in a variety of Gram-negative bacteria. In this study, we demonstrated that V. mimicus strain CS-66, isolated from a patient with diarrhea, was resistant to polymyxin B (PL-B) and colistin (CL) but susceptible to chloramphenicol and ciprofloxacin. When strain CS-66 was cultured in Luria–Bertani broth containing a sub-minimal inhibitory concentration of each antibiotic used for the susceptibility tests, ompV expression as assayed by reverse transcription-qPCR, significantly increased regardless of the antibiotic tested. In contrast, cell aggregation during the early log phase was observed only when the strain was grown in the broth supplemented with PL-B or CL. A space-filling model of V. mimicus OmpV was generated. The model showed that, although OmpV adopted a ƒĀ-barrel conformation, it had closed top and bottom ends and possessed a lateral cavity. Structural analysis further indicated that the interior of this lateral cavity was negatively charged and sufficiently large to accommodate PL-B. These results suggest that V. mimicus may adapt to PL-B stress through physical sequestration within the negatively charged cavity of OmpV. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 1201-9712 141 2024 Vibriosis in South Asia: A systematic review and meta-analysis 106955 EN Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kei Kitahara Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ayumu Ohno Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Januka Khatiwada Social Work Institute Shanta Dutta Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases Shin-Ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Objectives: South Asia remains home to foodborne diseases caused by the Vibrio species. We aimed to compile and update information on the epidemiology of vibriosis in South Asia. <br> Methods: For this systematic review and meta-analysis, we searched PubMed, Web of Science, EMBASE, and Google Scholar for studies related to vibriosis in South Asia published up to May 2023. A random-effects meta-analysis was used to estimate the pooled isolation rate of non-cholera-causing Vibrio species. <br> Results: In total, 38 studies were included. Seven of these were case reports and 22 were included in the meta-analysis. The reported vibriosis cases were caused by non-O1/non-O139 V. cholerae, V. parahaemolyticus, V. fluvialis, and V. vulnificus. The overall pooled isolation rate was 4.0% (95% confidence interval [CI] 3.0-5.0%) in patients with diarrhea. Heterogeneity was high (I-2 = 98.0%). The isolation rate of non-O1/non-O139 V. cholerae, V. parahaemolyticus, and V. fluvialis were 9.0 (95% CI 7.0-10.0%), 1.0 (95% CI 1.0-2.0%), and 2.0 (95% CI: 1.0-3.0%), respectively. Regarding V. parahaemolyticus, O3:K6 was the most frequently isolated serotype. Cases peaked during summer. Several studies reported antibiotic-resistant strains and those harboring extended-spectrum beta-lactamases genes. <br> Conclusions: This study demonstrates a high burden of infections caused by non-cholera-causing Vibrio species in South Asia. No potential conflict of interest relevant to this article was reported.

American Society for Microbiology Acta Medica Okayama 2576-098X 12 12 2023 Complete genomic sequence of Vibrio fluvialis strain IDH5335 isolated from a patient with diarrhea in Kolkata, India EN Goutam Chowdhury Collaborative Research Center of Okayama University for Infectious Diseases in India at ICMR-NICED Kei Kitahara Collaborative Research Center of Okayama University for Infectious Diseases in India at ICMR-NICED Makoto Taniguchi Oral Microbiome Center, Taniguchi Dental Clinic Kazuma Uesaka Graduate School of Bioagricultural Sciences, Nagoya University Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Debmalya Mitra Collaborative Research Center of Okayama University for Infectious Diseases in India at ICMR-NICED Ayumu Ohno Collaborative Research Center of Okayama University for Infectious Diseases in India at ICMR-NICED Thandavarayan Ramamurthy ICMR-National Institute of Cholera and Enteric Diseases Shanta Dutta ICMR-National Institute of Cholera and Enteric Diseases Shin-ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Asish Kumar Mukhopadhyay ICMR-National Institute of Cholera and Enteric Diseases We isolated a Vibrio fluvialis strain (IDH5335) from a stool sample collected from a patient with diarrhea. In this announcement, we report the complete genomic sequence of this organism, which was obtained by combining Illumina and Oxford Nanopore sequencing data. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0302-8933 205 10 2023 Flavobacterium okayamense sp. nov. isolated from surface seawater 346 EN Kei Kitahara Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Sho Morohoshi TechnoSuruga Laboratory Co., Ltd Tadao Kunihiro TechnoSuruga Laboratory Co., Ltd Nozomi Tazato TechnoSuruga Laboratory Co., Ltd Ayumu Ohno Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kazuma Uesaka Graduate School of Bioagricultural Sciences, Nagoya University Makoto Taniguchi Oral Microbiome Center, Taniguchi Dental Clinic Shin-ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Strain KK2020170T, a Gram-stain negative, yellow colony-forming bacterium, was isolated from surface seawater sampled in Kojima Bay, Okayama, Japan. Phylogenetic analysis based on the 16S rRNA gene revealed that strain KK2020170T belongs to the genus Flavobacterium, with Flavobacterium haoranii LQY-7T (98.1% similarity) being its closest relative, followed by Flavobacterium sediminis MEBiC07310T (96.9%) and Flavobacterium urocaniciphilum YIT 12746T (96.0%). Whole-genome shotgun sequencing showed that strain KK2020170T, when paralleled with F. haoranii LQY-7 T, had 81.3% average nucleotide identity, and 24.6% in silico DNA–DNA hybridization values, respectively. The DNA G + C content of strain KK2020170T was 31.1 mol%. The most abundant fatty acids (> 10%) of strain KK2020170T were iso-C15: 0, iso-C17: 0 3-OH and iso-C15: 1 G. The dominant respiratory quinone of the strain was menaquinone MK-6. Based on the phylogenetic and phenotypic analysis results, we propose that strain KK2020170T represents a novel species, for which the name Flavobacterium okayamense sp. nov. has been proposed. The type strain is KK2020170T (= ATCC TSD-280 T = NBRC 115344 T). No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 1477-8939 52 2023 Shigellosis in Southeast Asia: A systematic review and meta-analysis 102554 EN Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kei Kitahara Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Debmalya Mitra Collaborative Research Centre of Okayama University for Infectious Diseases in India at ICMR-NICED Ayumu Ohno Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Januka Khatiwada Social Work Institute Shanta Dutta Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases Shin-Ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Background: Southeast Asia is attractive for tourism. Unfortunately, travelers to this region are at risk of becoming infected with Shigella. We conducted a meta-analysis to provide updates on Shigella prevalence in Southeast Asia, along with their serogroups and serotypes.<br> Methods: We conducted a systematic search using PubMed, EMBASE, and Web of Science for peer-reviewed studies from 2000 to November 2022. We selected studies that detected Shigella in stools by culture or polymerase chain reaction (PCR). Two reviewers extracted the data using a standardized form and performed quality assessments using the Joanna Briggs Institute checklist. The random effects model was used to estimate the pooled prevalence of Shigella.<br> Results: During our search, we identified 4376 studies. 29 studies (from six Southeast Asian countries) were included in the systematic review, 21 each in the meta-analysis of the prevalence of Shigella (Sample size: 109545) and the prevalence of Shigella serogroups.<br> The pooled prevalence of Shigella was 4% (95% CI: 4–5%) among diarrhea cases. Shigella sonnei was the most abundant serogroup in Thailand (74%) and Vietnam (57%), whereas Shigella flexneri was dominant in Indonesia (72%) and Cambodia (71%). Shigella dysenteriae and Shigella boydii were uncommon (pooled prevalence of 1% each). The pooled prevalence of Shigella was 5% (95% CI: 4–6%) in children aged <5 years. The pooled prevalence showed a decreasing trend comparing data collected between 2000–2013 (5%; 95% CI: 4–6%) and between 2014–2022 (3%; 95% CI: 2–4%). Shigella prevalence was 6% in studies that included participants with mixed pathogens versus 3% in those without. Shigella flexneri serotype 2a was the most frequently isolated (33%), followed by 3a (21%), 1b (10%), 2b (3%), and 6 (3%).<br> Conclusions: This study provides compelling evidence for the development of effective Shigella vaccines for residents of endemic regions and travellers to these areas. No potential conflict of interest relevant to this article was reported.

Springer Nature Acta Medica Okayama 2055-0936 8 1 2022 Colonization with extended-spectrum beta-lactamase-producing Escherichia coli and traveler's diarrhea attack rates among travelers to India: a systematic review and meta-analysis 22 EN Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kei Kitahara Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ayumu Ohno Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Keinosuke Okamoto Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shin-Ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Background India is an attractive destination for travelers. Unfortunately, numerous reports exist on traveler's diarrhea (TD) and fecal colonization with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) among international travelers visiting India. Here, we systematically reviewed studies published on the acquisition of ESBL-EC and TD attack rates among international visitors to India. Methods Design: Systematic review and meta-analysis. A systematic search was performed using Google Scholar, PubMed, EMBASE, Web of Science, and gray literature from 2000 to December 2021, for studies containing data for ESBL-EC acquisition or TD experience related to a trip to India. Random effects models were used to compute the prevalence of ESBL-EC acquisition and TD attack. Results The literature search yielded a total of 5023 records. Of these, 31 met our inclusion criteria for systematic review and only 17 could be meta-analyzed (9 for TD, and 8 for ESBL-EC). The overall pooled attack rate of TD was 39% (95% confidence interval, CI: 25-53%). In studies where travelers' memory was used to diagnose TD, the pooled attack rate of TD was slightly higher (42%, 95% CI: 21-64%) compared to those where TD was objectively documented (33%, 95% CI: 17-49%). There were significant risks to be colonized with ESBL-EC among the travelers who experienced TD. The pooled rate of ESBL-EC colonization was 72% (CI: 67-78%). Most ESBL-EC produced CTX-M-15 enzyme. Furthermore, most of the travelers who acquired ESBL-EC were from highly industrialized countries recruited from travel clinics: Canada (n = 80), Germany (n = 69), Netherlands (n = 20), Sweden (n = 18), Japan (n = 10), Finland (n = 8), USA (n = 7), Spain (n = 5), and Denmark (n = 3). Conclusions TD pooled attack rate and ESBL-EC acquisition among international travelers visiting India were high in this study. However, we cannot make generalizations based upon this TD pooled attack rate for the current situation, due to a lack of current data. Our study highlights that travelers should be advised on TD to ensure that they do not disregard the risk of contracting TD and be better prepared as a result. It also illustrates the importance of international travel in acquiring antibiotic-resistant Escherichia coli. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2075-4418 11 11 2021 Cholera Rapid Diagnostic Tests for the Detection of Vibrio cholerae O1: An Updated Meta-Analysis 2095 EN Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kei Kitahara Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ayumu Ohno Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Anusuya Debnath Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Keinosuke Okamoto Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shin-Ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University The rapid diagnosis of cholera contributes to adequate outbreak management. This meta-analysis assesses the diagnostic accuracy of cholera rapid tests (RDTs) to detect Vibrio cholerae O1. Methods: Systematic review and meta-analysis. We searched four databases (Medline, EMBASE, Google Scholar, and Web of Science up to 8 September 2021) for studies that evaluated cholera RDTs for the detection of V. cholerae O1 compared with either stool culture or polymerase chain reaction (PCR). We assessed the studies' quality using the QUADAS-2 criteria. In addition, in this update, GRADE approach was used to rate the overall certainty of the evidence. We performed a bivariate random-effects meta-analysis to calculate the pooled sensitivity and specificity of cholera RDTs. Results: Overall, 20 studies were included in this meta-analysis. Studies were from Africa (n = 11), Asia (n = 7), and America (Haiti; n = 2). They evaluated eight RDTs (Crystal VC-O1, Crystal VC, Cholkit, Institut Pasteur cholera dipstick, SD Bioline, Artron, Cholera Smart O1, and Smart II Cholera O1). Using direct specimen testing, sensitivity and specificity of RDTs were 90% (95% CI, 86 to 93) and 86% (95% CI, 81 to 90), respectively. Cholera Sensitivity was higher in studies conducted in Africa [92% (95% CI, 89 to 94)] compared with Asia [82% (95% CI, 77 to 87)]. However, specificity [83% (95% CI, 71 to 91)] was lower in Africa compared with Asia [90% (95% CI, 84 to 94)]. GRADE quality of evidence was estimated as moderate. Conclusions: Against culture or PCR, current cholera RDTs have moderate sensitivity and specificity for detecting Vibrio cholerae O1. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1660-4601 19 9 2022 Cholera Outbreaks in India, 2011-2020: A Systematic Review 5738 EN Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kei Kitahara Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Anusuya Debnath Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ayumu Ohno Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Keinosuke Okamoto Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shin-Ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Fecal contamination of water sources and open defecation have been linked to cholera outbreaks in India. However, a systematic review on the drivers responsible for these outbreaks has yet to be published. Here, we systematically review the published literature on cholera outbreaks in India between 2011 and 2020. We searched studies in English in three databases (MEDLINE, EMBASE, and Web of Science) and the Integrated Disease Surveillance Program that tracks cholera outbreaks throughout India. Two authors independently extracted data and assessed the quality of the included studies. Quantitative data on the modes of transmission reviewed in this study were assessed for any change over time between 2011-2015 and 2016-2020. Our search retrieved 10823 records initially, out of which 81 full-text studies were assessed for eligibility. Among these 81 studies, 20 were eligible for inclusion in this review. There were 565 reported outbreaks between 2011 and 2020 that led to 45,759 cases and 263 deaths. Outbreaks occurred throughout the year; however, they exploded with monsoons (June through September). In Tamil Nadu, a typical peak of cholera outbreaks was observed from December to January. Seventy-two percent (33,089/45,759) of outbreak-related cases were reported in five states, namely Maharashtra, West Bengal, Punjab, Karnataka, and Madhya Pradesh. Analysis of these outbreaks highlighted the main drivers of cholera including contaminated drinking water and food, inadequate sanitation and hygiene (including open defecation), and direct contact between households. The comparison between 2011-2015 and 2016-2020 showed a decreasing trend in the outbreaks that arose due to damaged water pipelines. Many Indians still struggle with open defecation, sanitation, and clean water access. These issues should be addressed critically. In addition, it is essential to interrupt cholera short-cycle transmission (mediated by households, stored drinking water and foodstuffs) during an outbreak. As cholera is associated with deprivation, socio-economic development is the only long-term solution. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1660-4601 19 8 2022 Misconceptions and Rumors about Ebola Virus Disease in Sub-Saharan Africa: A Systematic Review 4714 EN Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ngangu Patrick Ntontolo Department of Family Medicine and Primary Health, Protestant University of Congo Nlandu Roger Ngatu Department of Public Health, Kagawa University Faculty of Medicine Januka Khatiwada Social Work Institute Tomoko Suzuki Department of Public Health, School of Medicine, International University of Health and Welfare Koji Wada Department of Public Health, School of Medicine, International University of Health and Welfare Kei Kitahara Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shunya Ikeda Department of Public Health, School of Medicine, International University of Health and Welfare Shin-Ichi Miyoshi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University We sought to summarize knowledge, misconceptions, beliefs, and practices about Ebola that might impede the control of Ebola outbreaks in Africa. We searched Medline, EMBASE, CINAHL, and Google Scholar (through May 2019) for publications reporting on knowledge, attitudes, and practices (KAP) related to Ebola in Africa. In total, 14 of 433 articles were included. Knowledge was evaluated in all 14 articles, and they all highlighted that there are misconceptions and risk behaviors during an Ebola outbreak. Some communities believed that Ebola spreads through the air, mosquito bites, malice from foreign doctors, witchcraft, and houseflies. Because patients believe that Ebola was caused by witchcraft, they sought help from traditional healers. Some people believed that Ebola could be prevented by bathing with salt or hot water. Burial practices where people touch Ebola-infected corpses were common, especially among Muslims. Discriminatory attitudes towards Ebola survivors or their families were also prevalent. Some Ebola survivors were not accepted back in their communities; the possibility of being ostracized from their neighborhoods was high and Ebola survivors had to lead a difficult social life. Most communities affected by Ebola need more comprehensive knowledge on Ebola. Efforts are needed to address misconceptions and risk behaviors surrounding Ebola for future outbreak preparedness in Africa. No potential conflict of interest relevant to this article was reported.

Public Library of Science Acta Medica Okayama 1932-6203 15 10 2021 Local perspectives on Ebola during its tenth outbreak in DR Congo: A nationwide qualitative study e0241120 EN Basilua Andre Muzembo Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ngangu Patrick Ntontolo Department of Family Medicine and Primary health, Protestant University of Congo Nlandu Roger Ngatu Department of Public Health, Kagawa University Faculty of Medicine Januka Khatiwada Department of Public Health, School of Medicine, International University of Health and Welfare Kabamba Leon Ngombe Department of Public Health, University of Kamina Oscar Luboya Numbi School of Public Health, University of Lubumbashi Kabamba Michel Nzaji School of Public Health, University of Lubumbashi Kabinda Jeff Maotela Centre National de Transfusion Sanguine Mukonkole Jean Ngoyi Research Unit, ISTM-Lubumbashi Tomoko Suzuki Department of Public Health, School of Medicine, International University of Health and Welfare Koji Wada Department of Public Health, School of Medicine, International University of Health and Welfare Shunya Ikeda Department of Public Health, School of Medicine, International University of Health and Welfare Background</br> The Democratic Republic of Congo (DR Congo) struggled to end the tenth outbreak of Ebola virus disease (Ebola), which appeared in North Kivu in 2018. It was reported that rumors were hampering the response effort. We sought to identify any rumors that could have influenced outbreak containment and affected prevention in unaffected areas of DR Congo.</br> Methods</br> We conducted a qualitative study in DR Congo over a period of 2 months (from August 1 to September 30, 2019) using in-depth interviews (IDIs) and focus group discussions (FGDs). The participants were recruited from five regional blocks using purposeful sampling. Both areas currently undergoing outbreaks and presently unaffected areas were included. We collected participantsf opinions, views, and beliefs about the Ebola virus. The IDIs (n = 60) were performed with key influencers (schoolteachers, religious and political leaders/analysts, and Ebola-frontline workers), following a semi-structured interview guide. FGDs (n = 10) were conducted with community members. Interviews were recorded with a digital voice recorder and simultaneous note-taking. Participant responses were categorized in terms of their themes and subthemes.</br> Results</br> We identified 3 high-level themes and 15 subthemes (given here in parentheses): (1) inadequate knowledge of the origin or cause of Ebola (belief in a metaphysical origin, insufficient awareness of Ebola transmission via an infected corpse, interpretation of disease as Godfs punishment, belief in nosocomial Ebola, poor hygiene, and bathing in the Congo River). Ebola was interpreted as (2) a plot by multinational corporations (fears of genocide, Ebola understood as a biological weapon, concerns over organ trafficking, and Ebola was taken to be the result of business actions). Finally Ebola was rumored to be subject to (3) politicization (political authorities seen as ambivalent, exclusion of some community leaders from response efforts, distrust of political authorities, and distrust in the healthcare system).</br> Conclusions</br> Due to the skepticism against Ebola countermeasures, it is critical to understand widespread beliefs about the disease to implement actions that will be effective, including integrating response with the unmet needs of the population. No potential conflict of interest relevant to this article was reported.