Serogroup O1 Research Articles

P-1846. Differences in Type 6 Secretion System Composition among Serogroups of Neonatal Meningitis Escherichia coli

Abstract Background Neonatal meningitis is a public health challenge for pediatricians. Neonatal meningitis Escherichia coli (NMEC) is the most common Gram-negative bacterial cause of sepsis and meningitis in newborns in the United States. NMEC strains can replicate in macrophages, survive in the bloodstream and traverse the blood-brain barrier, resulting in meningitis. Most NMEC cases are associated with serogroups O18, O83, O7, O12, O1, and O45 (Logue et al., 2012). Two clusters of the Type 6 Secretion System (T6SS-I and T6SS-II) were identified in an NMEC O18:K1 strain, and studies have demonstrated that T6SS plays an essential role in the pathogenesis of several bacterial species. However, there is still a lack of knowledge regarding the function of some T6SS genes. Here, we investigated the role of T6SS in different NMEC serogroups to identify specific genes that may be used as a potential target for an efficacious prevention strategy. Characteristics of NMEC strainsFigure 1.Characteristics of NMEC strains used in this study. A) Percentage of serogroups; B) Prevalence of T6SS among the NMEC isolates. Methods A total of 120 NMEC genomes were used in this study (n=78 from the Logue Lab collection; n=42 publicly databases). The T6SS clusters were identified through BLAST analysis using NMEC RS218 and O18 as reference genomes. To establish the presence of a specific cluster, a query cover and percentage identity threshold of 60% and 70% were set. The sequence comparisons were performed using the Artemis Comparison Tool (ACT). Results The serogroup O18 was the most abundant (23%; n=28), followed by O1 (22%; n=26), and O83 (12%; n=14). Analysis examined the prevalence of both T6SS clusters in the NMEC genomes and identified that they were present in 69% (n=83) of the genomes, while 12% (n=14) have only one of the clusters, and 19% (n=23) have no clusters. The presence of both T6SS clusters was observed in the serogroups O18, O14, and O2/O50. In contrast, no gene of any cluster was identified in serogroup O7. To understand the role of variation among the serogroups, in vitro analyses were performed. The results indicate differences in survival within THP-1 macrophages-like among distinct serogroups. Conclusion Our results support the hypothesis that T6SS components differ among the NMEC serogroups, potentially impacting their pathogenicity and ability to cause meningitis. These findings have significant implications for development of a prevention strategy for neonatal meningitis. Disclosures All Authors: No reported disclosures

Importance of Ompw gene to diagnose Vibrio cholerae isolated from stool and water samples

Background. Cholera is a severe acute watery diarrheal disease caused by O1 and O139 serogroup of Vibrio cholerae. The outer-membrane protein W (OmpW) a virulence factor, is involved in inducing protective immunity and triggering the immune response. The aim of this study is to find a rapid and accurate method for diagnosing Vibrio cholerae and investigate the possibility of OmpW gene to achieve this goal, and identify the effective antibiotic against this bacteria. Methods. The current study included 400 stool samples from patients who were suspected of having cholera and 50 samples of water have been collected from various water liquefaction stations in Thi-Qar province. The samples were examined by routine and advanced biochemical, serological methods and molecular method by using PCR to amplify 16S rDNA gene and gene OmpW. Results. Results of stool samples revealed that only 41 (10.25%) of the isolates were identified as Vibrio cholerae by biochemical methods while 38 (92.68%) of the isolates were diagnosed as Ogawa serotype of Vibrio cholerae serogroup O1 by serological and molecular methods. While the water samples did not reveal the appearance of Vibrio cholerae by molecular diagnosis. The study revealed a difference in the resistence rates of isolates to some antibiotics, with the highest percentage rate of resistance (100%) to trimethoprim-sulfamethoxazole while lowest percentage rate of resistance (5.26%) to piperacillin-tazobactam. Also, the study noted 56.58% of isolated V. cholera were resistant for tested antibiotics, 24.73% of isolated V. cholera were gave intermediate response, while 18.69% were sensitive for tested antibiotics. Conclusion. All identified isolates were registered in GenBank, two isolates with number LC793854 and LC793858 were recorded as new isolates. OmpW gene showed great accuracy to diagnose Vibrio cholerae, no less important than the accuracy of 16S rDNA gene to diagnose of these bacteria, and Piperacillin-tazobactam is the best antibiotic to treatment of cholera.

The Effect of Propolis on Hatched Eggs Previously Infected With Avian Pathogenic E. coli.

We investigated the effect of propolis as a sanitiser on hatched eggs previously infected with avian Pathogenic Escherichia coli (E. coli) (APEC) serogroup O78. A green propolis watery extract at 24% and a native breed hatching eggs have been used in this study. A total number of five virulence genes had been detected in E. coli serotype O78 used in this study indicating the pathogenicity of this isolate. The use propolis as a sanitiser for hatching eggs negatively decreased the hatchability percent and increased the embryonic death percent. However, it had a high strength against E. coli serogroup O78 as it significantly reduced the mean colony-forming unit (CFU) count in livers and yolks 4 days post-challenge and in 1-day-old chicks. Our results indicated the antibacterial effect of a green propolis watery extract at 24% against APEC serogroup O78. However, the effect of low concentrations of the propolis against hatchability and embryonic death rates should be tested.

Surveillance of Vibrio cholerae serogroups (O1 and O139) from surface and ground water sources in the Vhembe district, Limpopo province, South Africa

IntroductionVibrio cholera is increasingly emerging as a significant public health concern in developing countries. Choleragenic Vibrio cholerae O1 and O139 has reported to cause devastating disease and economic burdens in developing countries. In rural areas of the Vhembe district, most rivers and several communal boreholes are polluted as a result of sanitation issues around these water sources. The aim of this study was to determine the presence of choleragenic V. cholerae O1 and O139 in rivers and communal boreholes.MethodsThe analysis of physicochemical parameters and molecular techniques was used to establish the adaptation and detect the serogroups of V. cholerae in the water samples.Results and DiscussionThe results reported that electrical conductivities (EC) ranged between 18.78 and 154 μS/cm, with rivers such as Madandze and Mvudi recording >80 μS/cm, and those of the communal boreholes were ranged between 23.4 and 295 μS/cm, which were above the acceptable South African water quality guidelines of 0–70 μS/cm for rivers and communal boreholes. The results further revealed that most of the rivers detected positive for V. cholerae, except for the Mukhase river; the downstream points of Livuvhu and Nwedi rivers and the upstream point of the Nzhelele river; and several of the communal boreholes (Mak B1, B2, Kwe B3, 4, and 6) also tested positive for the presence of V. cholerae. The toxigenic Vibrios was also reported in Mutshundudi, Tshinane rivers, the upstream of Dzindi, Madanzhe, Nwedi, and the downstream of Sambandou rivers, as well as Mak B1, B2, and Kwe3 of communal boreholes. The serogroup O1 was detected on the Mutshundudi and Tshinane rivers, while serogroup O139 was detected upstream of the Dzindi, Madanzhe, Mutshundudi, and Tshinane rivers. There was also detection of the O1 serogroup in the communal boreholes (Mak B1 and Kwe B3), while O139 was only detected in one communal borehole (Mak B2). The development of robust policies, including an integrated water and sanitation safety surveillance web tool for monitoring water resources and public health protection, is required to make sure that drinking water in rural communities is safe for consumption.

Evolution and zoonotic risk of O1:K1 and O2:K1 avian pathogenic Escherichia coli.

The O1 and O2 serogroups of avian pathogenic E. coli (APEC) and human extraintestinal pathogenic E. coli (huExPEC) are closely related, but their evolutionary relationships need to be further elucidated. This study classified nineteen O1 and O2 APEC into rpoB sequence types (RSTs) and compared them with reference huExPEC using molecular prophage typing, virulence and antibiotic resistance gene profiling, and comparative genomics. Most O1:K1 and O2:K1 APEC (73.7%) were classified as RST46-1 and RST47-9. RST47-9 is unique to Korean O1 APEC and likely derives from RST46-1 APEC. The six APEC showed high genome coverage/identity with the Korean RST46-1 huExPEC. Based on RST network and comparative genomics, we hypothesized that the O1 antigen first appeared in RST19-1 and O2 in RST24-1 E. coli in humans. Then, O1 and O2-antigen horizontally transferred to human RST46-1, where a unique K1 capsule (K1-cps) first appeared. The Korean APEC and huExPEC share evolutionary CRISPR spacers but differ in molecular antibiograms and prophage contents. Thus, RST46-1 huExPEC transmitted and evolved in poultry. The zoonotic risks remain unknown, but the substantial virulence of the RST46-1 APEC indicates that the reverse zoonotic risk of huExPEC in poultry is alarming.

Antibiotic resistant Pseudomonas aeruginosa in dental unit waterline: a case study in Milan (Italy)

Abstract P.aeruginosa (Pa) is one of the most serious cause of healthcare-associated bacteremia, well-known for its antibiotic resistance (AR). Pa has often been found in dental unit water representing a great risk in public health. Aims are to evaluate the presence of Pa in dental unit (DU) water and its phenotypic and genotypic properties. Pa isolates derive from a monitoring of DU water in an Italian hospital (Milan). Samples were collected on Monday and on Friday, before the beginning and after the end of activities. Resistant PA strains were characterized by phenotypic method using E-test for 6 different classes of antibiotics, and by genotypic method with Whole-genome sequencing (WGS). Resistance genes were annotated with ResFinder v. 4.5 and Sequence Type (ST) was determined using the PA MLST database. 70/272 strains were identified as Pa and 21 of them were AR to one or more antibiotics. They were detected in 10/44 (22.7%) DUs and 2/4 (50%) control sinks (1-2000UFC/100mL). WGS was obtained for 18 strains. 17 belonged to serogroup O11 and ST667 was prevalent (8/18) followed by ST395 (4/18). At the ground floor ST395 was the most prevalent, followed by ST667 and 260, while, at the first floor, ST309 and 667 were in the two controls and ST667, 3245 and 260 in the other DUs. Resistant genes blaPAO, aph(3’)-IIb, catB7 conferring resistance to β-lactams, aminoglycosides and amphenicol, respectively, were observed in all isolates. Only ST3245 strain did not show resistance to Fosfomycin. Genotypic and phenotypic analyses present some discrepancies with the presence of AR genes and no antibiotic resistance detection (4/18) or resistance to other different classes of antibiotics (6/18). The MLST analyses showed a high diversity, with the presence of strains sharing different antibiotic resistance mechanisms in DU water. Detection and analyses by WGS can help to track dissemination of genetic resistance determinants and potential emergence of high-risk clones. Key messages • Phenotypic and genotypic analyses in DU water are needed to evaluate risk for human health, in addition to routine microbial monitoring. • WGS can help to track dissemination of genetic resistance determinants and potential emergence of high-risk clones.

Longitudinal study of avian pathogenic Escherichia coli (APEC) serogroups associated with disease in Georgia poultry using molecular serology and virulence gene analysis

ABSTRACT Avian pathogenic Escherichia coli (APEC) is a significant cause of morbidity, mortality, and production loss to the poultry industry worldwide. Here, we characterized 569 E. coli isolates from avian-diagnosed colibacillosis cases from the state of Georgia, USA. In total, 339 isolates were assigned into 32 serogroups with the majority classifying as O78, O2, O25, O8, O1, O86, O18, and O15. Serogroup O25 was found to link with broilers, while broiler breeders were more often associated with serogroup O1 and pet/ hobby birds with serogroup O8. In addition, some serogroups (O1) were more prevalent in the summer and fall. Analysis for virulence-associated genes (VAGs) found 23.20% of isolates did not harbour any genes linked with the APEC pathotype, while ColV plasmid-associated genes (iroN, ompT, hlyF, iss, and aerJ) were frequently detected among most isolates (with 80–96% prevalence) and some of these genes were linked with serogroup. Phylogenetic analysis, classified isolates into phylogenetic groups B2 (34%), F (19%), A (15%), and G (9%). The phylogenetic group B2 isolates also harboured the highest number of VAGs. This study highlights that the current APEC-causing disease in birds in the State of Georgia has identified several emerging serogroups possessing several VAGs that could potentially lead to challenges in colibacillosis control. RESEARCH HIGHLIGHTS Several emerging APEC serogroups were observed in Georgia poultry populations. An association between APEC serogroups and bird type was observed. The prevalence of different APEC serogroups was influenced by season. A multiplex PCR assay targeting common serogroups of APEC in Georgia poultry was developed.

Draft genomes of 10 Vibrio cholerae isolates collected in Sudan in 2019.

This report presents the first genomes from positive cases of cholera in Sudan. Genomic analysis of 10 Vibrio cholerae isolates, profiled as serogroup O1, reveals evidence of antimicrobial resistance genes and a 139-kb IncC plasmid with 99.74% identity to the multidrug-resistant plasmid pCNRVC190243 previously reported in Yemen and Lebanon.

Challenges and Considerations in Selecting Animal Models for Evaluating a Live, Cold-Chain-Free, Dual-Use Vaccine (MyChol) for Diarrhoeal Diseases: A Comprehensive Review.

Diarrhoeal diseases are the second leading cause of death for children under 5 years old in 69 low- and middle-income countries, with an annual economic burden of US$ 4 billion and over 525,000 lives lost. Cholera and enterotoxigenic Escherichia coli (ETEC) traveller's diarrhoea are major diarrhoeal diseases caused by Vibrio cholerae (O1 and O139 serogroups) and ETEC, which have similar pathogeneses and can co-infect. There is no exclusive vaccine for ETEC, but cholera vaccines containing the cholera toxin B (CT-B) component offer short-term cross-protection. However, licensed oral cholera vaccines are expensive due to cold-chain supplies and the need for multiple doses. A cost-effective, dual-protection, live, cold-chain-free vaccine is, therefore, required for vaccination campaigns in low-resource settings, and MyChol - a prototype cold-chain-free live attenuated cholera vaccine, targeting V. cholerae O139 and ETEC H10407 - was developed in this context. The vaccine was evaluated in three animal models (Sprague Dawley [SD] rats, BALB/c mice and New Zealand white rabbits) for safety, colonisation capacity, reactogenicity and immunogenicity against challenge strains. In suckling mice, MyChol displayed high colonisation potential compared to unformulated VCUSM14P (the vaccine candidate) and wild-type O139. In the acute toxicity assessment, the SD rats with the highest MyChol dose (1 × 107 colony-forming unit [CFU]/kg) demonstrated no adverse effects or mortality. Mice vaccinated with MyChol exhibited elevated antibody levels, including anti-CT, anti-heat-labile enterotoxin (LT), anti-CT-B and anti-LT-B. Anti-CT antibodies neutralised LT toxin in ETEC H10407 in challenge studies and cross-protected against ETEC H10407 in both mice and rabbits, preventing weight loss and diarrhoea. Ileal loop experiments in rabbits and BALB/c mice showed no reactogenicity. This review, based on our previous research, therefore provides valuable insights into improving the selection of animal models to advance preclinical evaluations of diarrhoeal vaccines.

Diversity and Complexity of CTXΦ and Pre-CTXΦ Families in Vibrio cholerae from Seventh Pandemic.

CTXΦ is a lysogenic filamentous phage that carries the genes encoding cholera toxin (ctxAB), the main virulence factor of Vibrio cholerae. The toxigenic conversion of environmental V. cholerae strains through CTXΦ lysogenic infection is crucial for the emergence of new pathogenic clones. A special allelic form of CTXΦ, called pre-CTXΦ, is a precursor of CTXΦ and without ctxAB. Different members of the pre-CTXΦ and CTXΦ families are distinguished by the sequence of the transcriptional repressor-coding gene rstR. Multiple rstR alleles can coexist within a single strain, demonstrating the diverse structure and complex genomic integration patterns of CTXΦ/pre-CTXΦ prophage on the chromosome. Exploration of the diversity and co-integration patterns of CTXΦ/pre-CTXΦ prophages in V. cholerae can help to understand the evolution of this phage family. In this study, 21 V. cholerae strains, which were shown to carry the CTXΦ/pre-CTXΦ prophages as opposed to typical CTXETΦ-RS1 structure, were selected from approximately 1000 strains with diverse genomes. We identified two CTXΦ members and six pre-CTXΦ members with distinct rstR alleles, revealing complex chromosomal DNA integration patterns and arrangements of different prophages in these strains. Promoter activity assays showed that the transcriptional repressor RstR protected against CTXΦ superinfection by preventing the replication and integration of CTXΦ/pre-CTXΦ phages containing the same rstR allele, supporting the co-integration of the diverse CTXΦ/pre-CTXΦ members observed. The numbers and types of prophages and their co-integration arrangements in serogroup O139 strains were more complex than those in serogroup O1 strains. Also, these CTXΦ/pre-CTXΦ members were shown to present the bloom period of the CTXΦ/pre-CTXΦ family during wave 2 of the seventh cholera pandemic. Together, these analyses deepen our comprehension of the genetic variation of CTXΦ and pre-CTXΦ and provide insights into the evolution of the CTXΦ/pre-CTXΦ family in the seventh cholera pandemic.

Epidemiology and antimicrobial resistance profiles of pathogenic Escherichia coli from commercial swine and poultry abattoirs and farms in South Africa: A One Health approach

Pathogenic Escherichia coli (PEC) are important foodborne bacteria that can cause severe illness in humans. The PECs thrive within the intestines of humans as well as animals and may contaminate multiple ecosystems, including food and water, via faecal transmission. Abattoir and farm employees are at high risk of PEC exposure, which could translate to community risk through person-to-person contact. To determine the epidemiology and resistome of PECs in Gauteng and Limpopo provinces of South Africa, 198 swine faecal samples, 220 poultry cloacal swabs, 108 human hand swabs, 11 run-off water samples from abattoirs and farms were collected from four swine and five poultry commercial abattoirs and two swine farms. One effluent sample each was collected from four wastewater treatment plants (WWTP) and a tertiary hospital setting. Phenotypic and genotypic techniques were used including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Results showed EHEC and EPEC prevalence was 4.1 % (22/542) and 20.8 % (113/542), respectively, with the O26 serogroup detected the most in PEC isolates. According to the PFGE dendrogram, isolates from poultry, human hand swabs and run-off water clustered together. Diverse virulence factors such as the novel stx2k subtype and eae genes were detected among the 36 representative PEC isolates according to WGS. The results showed that 66.7 % (24/36) of sequenced PECs presented with multi-drug resistance (MDR) to β-lactamase 13.9 % (5/36), aminoglycoside 61.1 % (22/36), tetracycline 41.7 % (15/36) and quinolones 38.9 % (14/36). No colistin nor carbapenem resistance was detected. Sequence types (STs) associated with MDR in this study were: ST752, ST189, ST206, ST10, ST48 and ST38. The findings highlight the threat of zoonotic pathogens to close human contacts and the need for enhanced surveillance to mitigate the spread of MDR foodborne PECs.

Prevalence and antimicrobial susceptibility pattern of Vibrio cholerae isolates from cholera outbreak sites in Ethiopia

BackgroundCholera is an acute infectious disease caused by ingestion of contaminated food or water with Vibrio cholerae. Cholera remains a global threat to public health and an indicator of inequity and lack of social development. The aim of this study was to assess the prevalence and antimicrobial susceptibility pattern of V. cholerae from cholera outbreak sites in Ethiopia.MethodsAcross-sectional study was conducted from May 2022 to October 2023 across different regions in Ethiopia: Oromia National Regional State, Amhara National Regional State and Addis Ababa City Administration. A total of 415 fecal samples were collected from the three regions. Two milliliter fecal samples were collected from each study participants. The collected samples were cultured on Blood Agar, MacConkey Agar and Thiosulfate Citrate Bile Salt Sucrose Agar. A series of biochemical tests Oxidase test, String test, Motility, Indole, Citrate, Gas production, H2S production, Urease test were used to identify V. cholerae species. Both polyvalent and monovalent antisera were used for agglutination tests to identify and differentiate V. cholerae serogroup and serotypes. In addition, Kirby-Bauer Disk diffusion antibiotic susceptibility test method was done. Data were registered in epi-enfo version 7 and analyzed by Statistical Package for Social Science version 25. Descriptive statistics were used to determine the prevalence of Vibrio cholerae. Logistic regression model was fitted and p-value < 0.05 was considered as statically significant.ResultsThe prevalence of V. cholerae in the fecal samples was 30.1%. Majority of the isolates were from Oromia National Regional State 43.2% (n = 54) followed by Amhara National Regional State 31.2% (n = 39) and Addis Ababa City Administration 25.6% (n = 32). Most of the V. cholerae isolates were O1 serogroups 90.4% (n = 113) and Ogawa serotypes 86.4% (n = 108). Majority of the isolates were susceptible to ciprofloxacin 100% (n = 125), tetracycline 72% (n = 90) and gentamycin 68% (n = 85). More than half of the isolates were resistant to trimethoprim-sulfamethoxazole 62.4% (n = 78) and ampicillin 56.8% (n = 71). In this study, participants unable to read and write were about four times more at risk for V. cholerae infection (AOR: 3.8, 95% CI: 1.07–13.33). In addition, consumption of river water were about three times more at risk for V. cholerae infection (AOR: 2.8, 95% CI: 1.08–7.08).Conclusionour study revealed a high prevalence of V. cholerae from fecal samples. The predominant serogroups and serotypes were O1 and Ogawa, respectively. Fortunately, the isolates showed susceptible to most tested antibiotics. Drinking water from river were the identified associated risk factor for V. cholerae infection. Protecting the community from drinking of river water and provision of safe and treated water could reduce cholera outbreaks in the study areas.

Genomic insights into the 2022–2023Vibrio cholerae outbreak in Malawi

Malawi experienced its deadliest Vibrio cholerae (Vc) outbreak following devastating cyclones, with >58,000 cases and >1700 deaths reported between March 2022 and May 2023. Here, we use population genomics to investigate the attributes and origin of the Malawi 2022–2023 Vc outbreak isolates. Our results demonstrate the predominance of ST69 clone, also known as the seventh cholera pandemic El Tor (7PET) lineage, expressing O1 Ogawa (~ 80%) serotype followed by Inaba (~ 16%) and sporadic non-O1/non-7PET serogroups (~ 4%). Phylogenetic reconstruction revealed that the Malawi outbreak strains correspond to a recent importation from Asia into Africa (sublineage AFR15). These isolates harboured known antimicrobial resistance and virulence elements, notably the ICEGEN/ICEVchHai1/ICEVchind5 SXT/R391-like integrative conjugative elements and a CTXφ prophage with the ctxB7 genotype compared to historical Malawian Vc isolates. These data suggest that the devastating cyclones coupled with the recent importation of 7PET serogroup O1 strains, may explain the magnitude of the 2022–2023 cholera outbreak in Malawi.

Antigenicity evaluation of synthetic α-(1,3)-linked D, D-heptoglycan of Helicobacter pylori serotype O6 lipopolysaccharide

Helicobacter pylori, a gram‐negative bacterium, is known to be associated with various gastric pathologies including chronic gastritis, peptic ulcers and gastric carcinoma. Despite the emerging issue of bacterial resistance to antibiotic-based combination therapy, there is currently no vaccine available for H. pylori infection in the market. Here, we report the synthesis of α-(1,3)-D,D-heptoglycan with different chain length from the lipopolysaccharide of H. pylori serogroup O6. The [n + 1] iterative glycosylation strategy was used for heptoglycan chain elongation. The trifluoroacetimidate heptoside donor exhibited much higher efficiency than thioglycoside donor during glycosylation. An antigenicity evaluation using glycan microarrays indicated that α-(1,3)-D,D-hepto-disaccharide, pentasaccharide and hexasaccharide showed stronger binding affinity to IgG antibodies of H. pylori O6 LPS immunized rabbit serum or serum of H. pylori infected patients. These findings provide significant structure − activity relationship information for developing carbohydrate-based vaccines against H. pylori containing α-(1,3)-D,D-heptoglycan.

Epidemiological Situation on Cholera in the Russian Federation in 2023 and Forecast for 2024

The paper presents an analysis and assessment of risks of complication of epidemiological situation regarding cholera in the Russian Federation and a forecast for 2024. It briefly characterizes the dynamics of the epidemic process around the world during the last decade (2013–2022). The forecast of cholera importation into the Russian Federation, due to activity of the epidemic process in endemic countries, has been confirmed. In 2023, two cases of cholera importation from India were reported. It was established that the toxigenic strains isolated from patients belonged to the currently dominant in the world “post-Haitian” group, including in India and Bangladesh, with the genotype ctxB7 tcpACIRS rtxA4a VSP-IIΔ0495-0512. Furthermore, non-toxigenic Vibrio cholerae O1 strains were isolated from samples of biological material from persons arriving from India, containing preCTX prophage and distinct from the strain (ctxAB– tcpAEТ–) isolated from a patient with acute intestinal infection (Zaporozhye Region, Melitopol). Nontoxigenic NAG vibrios were isolated from 13 patients with acute intestinal infections, which is 1.9 times more than in 2022. Regardless of importations, a strain of V. cholerae O1 (ctxB1+tcpAEТ) of the “pre-Haitian” group was isolated from a water sample of a surface reservoir. 52 non-toxigenic V. сholerae O1 strains were found on the territory of 11 constituent entities of the Russian Federation, which is 18.9 % more than in 2022. In 2024, epidemiological risks of cholera importation from endemic countries to any administrative territory of the Russian Federation remain. The risks of epidemic manifestations of cholera are especially high in the territories of the constituent entities of the Russian Federation which are under ongoing emergency, due to migration processes, and the impact of other risk-forming factors that contribute to an increase in the degree of contact of the population with water bodies contaminated with cholera vibrios. If epidemic foci of cholera are to emerge in a neighboring country, there will be a high probability of spread of this infection in the stated constituent entities of the Russian Federation and in other territories of southern Russia. In the absence of epidemic manifestations of cholera, the possibility of occasional detection of toxigenic O1 serogroup strains in water samples due to unidentified introductions from cholera-affected areas cannot be ruled out.

Non-O1/non-O139 Vibrio cholerae bacteraemia and cholangitis: An unusual case in an oncological patient in Lecco Hospital, Italy

Vibrio species are curved, motile, aerobic and facultative anaerobic, Gram-negative bacilli that are widely distributed in aquatic environments, especially marine and estuarine waters. Vibrios of primary concern in human pathology are essentially represented by the species Vibrio cholerae. Classification of Vibrio cholerae is based on the O-antigen polysaccharide type, with over 200 serogroups described. Historically, only toxigenic serogroups O1 and O139 have been associated with widespread cholera epidemics. Other serogroups can cause small outbreaks that spread via contaminated raw seafood (primarily shellfish and molluscs) and seawater exposure, and they are collectively termed Non-O1/Non-O139 Vibrio Cholerae (NOVC). NOVC, occasionally detected also in the Mediterranean Sea, most often causes sporadic gastrointestinal manifestations requiring supportive therapy. However, rarely the V. cholerae non-O1/ non-O139 serotype can result in extraintestinal manifestations such as severe wound infections, soft tissue infections and sepsis in immunocompromised patients that represent a therapeutic challenge. In particular, NOVC bacteraemia is a rare event but has the highest mortality rates among NOVC infections (almost 33%) and usually occurs in certain immunosuppressed populations, such as patients with haematologic and solid malignancies, and those with underlying liver disease.

Un caso di diffusione intra-familiare di colera

Cholera is an acute diarrhoeal disease caused by Vibrio cholerae (VC) serogroups O1 and O139. Transmission is oro-faecal and it might lead to acute dehydration. The disease is still endemic in resource-poor countries, nevertheless importation cases are occasionally reported in developed countries. The paper reports a case of a 3-year-old boy admitted to the emergency room because of acute gastroenteritis with rice-water stools. Faecal samples were positive for VC. The child was managed with prompt parenteral crystalloid infusion, followed by oral rehydration solution. After a single dose of azythromicin, a progressive reduction in symptoms was documented. Cholera infection is then briefly reviewed.

Cholera in Nigeria: A review of outbreaks, trends, contributing factors, and public health responses.

Cholera remains a significant public health challenge in Nigeria, with recurrent outbreaks exacerbated by inadequate water, sanitation, and hygiene (WASH) infrastructure, as well as conflict and displacement. This review examines cholera outbreaks in Nigeria from 2010 to 2024, analyzing epidemiological trends, contributing factors, and public health responses. Seasonal peaks during periods of heavy rainfall and flooding have consistently facilitated Vibrio cholerae transmission, with Northern regions disproportionately affected due to poor infrastructure and ongoing conflicts. Displacement into overcrowded camps has heightened vulnerability, particularly in conflict-affected areas such as Borno and Adamawa. The outbreaks have exhibited multiple epidemic waves within single periods, reflecting persistent transmission dynamics. Recent outbreaks have seen higher incidence rates among children under the age of five and vulnerable populations, highlighting the need for targeted interventions. Public health responses have focused on improving surveillance, case management, and WASH infrastructure, with coordinated efforts from national and international agencies. Vaccination campaigns, particularly in high-risk areas, have proven effective in controlling outbreaks. However, challenges remain, including inadequate healthcare capacity, vaccine stockouts, and the emergence of antimicrobial-resistant Vibrio cholerae strains (serogroup O1) resistant to antibiotics such as tetracycline, doxycycline, ampicillin, and trimethoprim-sulfamethoxazole, complicating treatment efforts. The COVID-19 pandemic further strained Nigeria's healthcare system, underscoring the need for an integrated health system to be strengthened to manage concurrent public health crises. This review emphasizes the importance of a multi-sectoral approach to cholera prevention and control, addressing underlying social determinants and ensuring sustained investments in public health infrastructure to mitigate future outbreaks.

Ингибиторный анализ протеаз препаратов бесклеточных фракций холерных вибрионов

One of the important areas of research into the pathogenesis of diseases caused by pathogens of especially dangerous infections is the study of the system of hydrolytic enzymes. It has been established that hydrolytic enzymes of pathogenic microorganisms enhance their pathogenicity (virulence) and participate in the processes of adaptation to unfavourable environmental factors. Cholera vibrio has previously electrophoretically detected hydrolases belonging to different subclasses and established differences in their spectrum in strains with different epidemic significance. Therefore, the study of their characterisation (type determination using activator/inhibitor assays) is a relevant area of research. The inhibitor analysis of secreted proteases of cholera vibrio strains of O1 serogroup El Tor biovar and O139 serogroup determined that the proteases include serine and metalloproteases.

Ингибиторный анализ протеаз препаратов бесклеточных фракций холерных вибрионов

One of the important areas of research into the pathogenesis of diseases caused by pathogens of especially dangerous infections is the study of the system of hydrolytic enzymes. It has been established that hydrolytic enzymes of pathogenic microorganisms enhance their pathogenicity (virulence) and participate in the processes of adaptation to unfavourable environmental factors. Cholera vibrio has previously electrophoretically detected hydrolases belonging to different subclasses and established differences in their spectrum in strains with different epidemic significance. Therefore, the study of their characterisation (type determination using activator/inhibitor assays) is a relevant area of research. The inhibitor analysis of secreted proteases of cholera vibrio strains of O1 serogroup El Tor biovar and O139 serogroup determined that the proteases include serine and metalloproteases.