Diarrheal Pathogens Research Articles

Systematic Surveillance of an Emerging Picornavirus among Cattle and Sheep in China.

Emerging viruses are a constant threat to human and animal health. Boosepivirus is a novel picornavirus considered a gastrointestinal pathogen and has broken out in recent years. In 2020, we identified a strain of boosepivirus NX20-1 from Chinese calf feces and performed genetic characterization and evolutionary analysis. NX20-1 was closely related to the Japanese strain Bo-12-38/2009/JPN and belonged to Boosepivirus B. We found that 64 of 603 samples (10.6%) from 20 different provinces across the country were positive for boosepivirus by reverse transcription (RT)-PCR. Further, coinfection with other diarrheal pathogens was also present in 35 of these positive samples. Importantly, we found the prevalence of boosepivirus in sheep as well, indicating that Boosepivirus can infect different domestic animals. Our data suggest that boosepivirus is a potential diarrheal pathogen, but the pathogenicity and the mechanism of pathogenesis need further study. IMPORTANCE We identified a novel picornavirus, boosepivirus, for the first time in China. Genetic evolutionary analysis revealed that NX20-1 strain was closely related to the Japanese strain Bo-12-38/2009/JPN and belonged to Boosepivirus B. In addition, we found that the virus was prevalent in China with an overall positivity rate of 10.6% (64 of 603 samples), and there was significant coinfection with other pathogens. Importantly, we found the prevalence of boosepivirus in sheep as well, suggesting that boosepivirus has a risk of spillover and can be transmitted across species.

Arcobacter species isolated from various seafood and water sources; virulence genes, antibiotic resistance genes and molecular characterization

Arcobacter spp. has gained clinical significance as an emerging diarrheagenic pathogen associated with water reservoirs in recent years. The complete clinical significance of Arcobacter remains rather speculative due to the virulence and antibiotic susceptibility of individual strains. This study aimed to assess the prevalence of Arcobacter spp. in fish, water, and shellfish. A total of 150 samples were collected from the Adana, Kayseri and Kahramanmaras provinces in Turkey. Arcobacterspp. was isolated from 32 (21%) of the 150 samples. The most prevalent species was A. cryaerophilus, 17 (56%), A. butzleri 13 (37%) and A. lacus 2 (6%). As a result, the ratios of the mviN, irgA, pldA, tlyA and hecA target genes were found as 17 (51%), 1 (3%), 7 (23%), 7 (23%), 1 (3%), respectively. While bla OXA-61, tetO and tetW were positive in all isolates, were found as mcr1/2/6, mcr3/7, and mcr5, genes %37.5, %25, and %34.3, respectively. Although in A. butzleri was found 10 (58%), 1 (3%), 3 (43%), 2 (28%) (mviN, irgA, pldA, and tlyA, respectively) virulence genes 7 (42%), 4 (57%), 5 (72%), 1 (3%) was found (mviN, irgA, tlyA, and hecA, respectively) virulence genes in A. cryoaerophilus. Moreover, was found for the mcr 1/2/6 7 (58%) genes, for the mcr 3/7 genes 3 (38%) in A. butzleri. In A. cryoaerophilus was found for the mcr 1/2/6 genes 5 (42%), for the mcr 3/7 genes 5 (62%), and for the mcr 5 gene 10 (100%). Thus, the current study indicated that the existence of Arcobacter spp. isolated from fish and mussel samples may pose a potential risk to public health.

Colonizing and Virulence Factors in Enterotoxigenic Escherichia coli from Peru.

Enterotoxigenic Escherichia coli (ETEC) ranks among the most relevant diarrheagenic pathogens. Efforts to design vaccines to fight ETEC have been focused on colonizing factors (CFs) and atypical virulence factors (AVF). An effective vaccine must account for differences in the regional prevalence of these CFs and AVFs to be truly effective in a given area. In the present study, the presence of 16 CFs and 9 AVFs, as well as the heat-stable (ST) variants (STh or STp), was established by polymerase chain reaction in 205 Peruvian ETEC isolates (120 from diarrhea cases and 85 from healthy controls). Ninety-nine (48.3%) isolates were heat-labile, 63 (30.7%) ST, and 43 (21.0%) presented both toxins. Of ST isolates, 59 (28.8%) possessed STh, 30 (14.6%) STp, five (2.4%) both STh and STp, and 12 (5.8%) were not amplified for any variant tested. The presence of CFs was associated with diarrhea (P < 0.0001). The presence of eatA as well as concomitant presence of CSI, CS3, and CS21 and of C5 and C6 was statistically related to diarrhea cases. The present results suggests that, if effective, a vaccine considering CS6, CS20, and CS21, together with EtpA, would provide protection against 64.4% of the isolates analyzed, whereas the addition of CS12 and EAST1 would lead to 83.9% coverage. Large studies are needed to establish both the ideal candidates to be considered to develop a vaccine effective in the area, and continuous surveillance is needed to detect displacement of circulating isolates that may compromise future vaccines.

The role of Nod-like receptors in modulating the microbiota-gut-brain axis following neonatal bacterial infection

Objective: Pediatric infection with diarrheal pathogens causes cognitive deficits in adulthood via an unknown mechanism. Neonatal infection with a bacterial enteric pathogen disrupts the development of the microbiota-gut-brain (MGB) axis in adult mice. Given the role of pattern recognition receptors, including Nucleotide Oligomerization Domain 1 (Nod1) in innate immune responses to infection, our objective was to establish their role in disrupted MGB axis communication following neonatal enteropathogenic Escherichia coli (EPEC) infection. Hypothesis: Intestinal epithelial cell (IEC) Nod1 modulates disrupted MGB axis communication following neonatal EPEC infection. Methods: C57BL/6 (male/female) IEC Nod1 conditional knockout mice (IEC cKO; Cre+) and wild type (WT) littermate controls (Cre-) were used. Neonatal mice were infected on postnatal day 7 (P7) with EPEC (10 5 CFU; strain e2348/69; orogastric gavage), or vehicle control (Luria broth). Colonization was assessed at P14 and P21 (MacConkey agar plating) and disease monitored via weight loss and ileal inflammation (qPCR). Behavior and neuroinflammation were assessed in adulthood (6-8 weeks). Behavioral tests included the novel object recognition task (NOR) for cognitive function, the light/dark (L/D) box for anxiety-like behavior, and open field test (OFT) for general and locomotor behavior. Results: Neonatally EPEC-infected Nod1 cKO mice demonstrated blunted ileal inflammation, with similar decreased expression of Il6, Tlr2, Tlr4, and Nod2 in cKO vs WT EPEC-infected mice ( P = NS, n = 4-6 ), with no evidence of inflammation in uninfected controls (WT or cKO). In contrast, evidence of hippocampal neuroinflammation was present in EPEC-infected Nod1 cKO mice, with increased expression of Iba1, Il6, and Il22 ( P &lt; 0.0001, n = 4-6), compared to sham-infected Nod1 cKO mice or uninfected control mice. In addition, EPEC-infected Nod1 cKO mice demonstrated decreased hippocampal expression of the neurogenesis marker Bdnf ( P &lt; 0.0001, n ≥ 4) compared to EPEC-infected WT mice, or uninfected mice. With respect to behavior, EPEC-infected WT mice had a lower exploration ratio (49.5 ± 1.7% vs. 54.6 ± 1.7%, P = 0.0035, n ≥ 8), whereas EPEC-infected Nod1 cKO mice displayed normal exploration of a novel object compared to uninfected Nod1 cKO mice ( P = NS, n = 10-12), without impacting anxiety-like behavior ( P = NS, n = 10-12). Conclusions: IEC Nod1 is important for maintaining MGB axis communication following neonatal EPEC infection. We speculate that decreased ileal inflammation due to absence of Nod1 IEC expression prevents cognitive deficits in adulthood, despite the evidence of neuroinflammation and impaired neurogenesis. Inflammation in the gut and brain will be further characterized by immunofluorescence in ongoing studies. NIH R01AT009365; NIH R21MH108154. Olivia Orahood is an active-duty member of the United States Space Force. The views expressed in this article are those of the author and do not reflect the official policy or position of the United States Space Force, United States Air Force, Department of Defense, or the U.S. Government This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Susceptibility antibiotic screening reveals high rates of multidrug resistance of Salmonella, Shigella and Campylobacter in HIV infected and uninfected patients from Mozambique

BackgroundAntibacterial resistance is a growing concern worldwide, including in Mozambique. Diarrhea is an important cause of mortality in Mozambique, yet few local studies have reported on the resistance of bacterial pathogens in this context. Therefore, this study aims to characterize antibiotic susceptibility patterns of Salmonella, Shigella and Campylobacter spp. among patients with diarrhea, including those who are HIV-infected and-uninfected.MethodsWe conducted antibiotic susceptibility testing on 157 stool isolates recovered from 129 patients aged between 0 and 80 years with diarrhea, including HIV infected (n = 68) and-uninfected individuals (n = 61), assisted at two health centers in Maputo city. The isolates comprised of 99 Salmonella, 45 Shigella and 13 Campylobacter strains. The Kirby-Bauer disk diffusion method was used on Mueller-Hinton II agar for Salmonella and Shigella spp., while Mueller-Hinton II agar with 5% defibrinated sheep blood was used for Campylobacter spp. We tested six antibiotics listed on the national essential medicines list, including ciprofloxacin, erythromycin, azithromycin, trimethoprim-sulfamethoxazole, gentamicin, and tetracycline.ResultsAll isolates were resistant to at least one antibiotic. A high percentage of Salmonella spp. isolates were found to be resistant to trimethoprim-sulfamethoxazole (89.9%, n = 89), erythromycin (88.9%, n = 88) and tetracycline (76.8%, n = 76). In addition, 86.6% (n = 39) and 68.9% (n = 31) of Shigella isolates were resistant to trimethoprim-sulfamethoxazole and tetracycline, respectively. The majority of Campylobacter isolates (92.3%, n = 12) were resistant to erythromycin, azithromycin and tetracycline. Multidrug resistance (MDR) was observed in 79.8% of Salmonella spp., 76.9% of Campylobacter spp., and 57.8% of Shigella spp. Drug susceptibility profiles for Salmonella spp. and Campylobacter were similar in both HIV-1 infected and uninfected patients. However, Shigella spp. isolates obtained from patients without HIV infection were significantly more likely to be resistant to erythromycin, azithromycin or to exhibit multidrug resistance than those obtained from patients with HIV-1 infection (p < 0.05). All Shigella spp. and Campylobacter spp. isolates were susceptible to gentamicin.ConclusionOur study highlights concerning rates of antibiotic resistance and MDR among diarrheal bacterial pathogens in Mozambique. Further research is needed to understand the impact of HIV, ART therapy and immunosuppression on antibiotic resistance. Urgent interventions are essential to prevent the spread of resistant strains.

Stunting Following Moderate-to-Severe Diarrhea Among Children Aged &amp;lt;5 Years in Africa Before and After Rotavirus Vaccine Introduction: A Comparison of the Global Enteric Multicenter Study and the Vaccine Impact on Diarrhea in Africa (VIDA) Study

Studies conducted before rotavirus vaccine introduction found that moderate-to-severe diarrhea (MSD) in children aged <5 years was associated with stunting at follow-up. It is unknown whether the reduction in rotavirus-associated MSD following vaccine introduction decreased the risk of stunting. The Global Enteric Multicenter Study (GEMS) and the Vaccine Impact on Diarrhea in Africa (VIDA) study, two comparable matched case-control studies, were conducted during 2007-2011 and 2015-2018, respectively. We analyzed data from 3 African sites where rotavirus vaccine was introduced after GEMS and before starting VIDA. Children with acute MSD (<7 days onset) were enrolled from a health center and children without MSD (diarrhea-free for ≥7 days) were enrolled at home within 14 days of the index MSD case. The odds of being stunted at a follow-up visit 2-3 months after enrollment for an episode of MSD was compared between GEMS and VIDA using mixed-effects logistic regression models controlling for age, sex, study site, and socioeconomic status. We analyzed data from 8808 children from GEMS and 10 579 from VIDA. Among those who were not stunted at enrollment in GEMS, 8.6% with MSD and 6.4% without MSD became stunted during the follow-up period. In VIDA, 8.0% with MSD and 5.5% children without MSD developed stunting. An episode of MSD was associated with higher odds of being stunted at follow-up compared with children without MSD in both studies (adjusted odds ratio [aOR], 1.31; 95% confidence interval [CI]: 1.04-1.64 in GEMS and aOR, 1.30; 95% CI: 1.04-1.61 in VIDA). However, the magnitude of association was not significantly different between GEMS and VIDA (P = .965). The association of MSD with subsequent stunting among children aged <5 years in sub-Saharan Africa did not change after rotavirus vaccine introduction. Focused strategies are needed for prevention of specific diarrheal pathogens that cause childhood stunting.

Pathophysiology of Enteropathogenic Escherichia coli-induced Diarrhea.

Enteropathogenic Escherichia coli (EPEC) are important diarrheal pathogens of infants and young children. Since the availability of molecular diagnosis methods, we now have new insights into the incidence and prevalence of these infections. Recent epidemiological studies indicate that atypical EPEC (aEPEC) are seen more frequently than typical EPEC (tEPEC) worldwide, including in both endemic diarrhea and diarrhea outbreaks. Therefore, it is important to further characterize the pathogenicity of these emerging strains. The virulence mechanisms and pathophysiology of the attaching and effacing lesion (A/E) and the type-three-secretion-system (T3SS) are complex but well-studied. A/E strains use their pool of locus of enterocyte effacement (LEE)-encoded and non-LEE-encoded effector proteins to subvert and modulate cellular and barrier properties of the host. However, the exact mechanisms of diarrhea in EPEC infection are not completely understood. From the clinical perspective, there is a need for fast, easy, and inexpensive diagnostic methods to define optimal treatment and prevention for children in endemic areas. In this article, we present a review of the classification of EPEC, epidemiology, pathogenesis of the disease caused by these bacteria, determinants of virulence, alterations in signaling, determinants of colonization vs. those of disease, and the limited information we have on the pathophysiology of EPEC-induced diarrhea. This article combines peer-reviewed evidence from our own studies and the results of an extensive literature search in the databases PubMed, EMBASE, and Scopus.

Molecular Prevalence of Diarrheal Pathogens in Children with Acute Diarrhea in Southeastern Gabon.

Diarrheal diseases are a major cause of morbidity and mortality in infants and young children, particularly in sub-Saharan countries. In Gabon, there are few data on the prevalence of diarrheal pathogens in children. The aim of this study was to assess the prevalence of diarrheal pathogens in children with diarrhea in southeastern Gabon. Stool samples (n = 284) from Gabonese children 0 to 15 years of age with acute diarrhea were analyzed using polymerase chain reaction targeting 17 diarrheal pathogens. At least one pathogen was detected in 75.7% of samples (n = 215). Coinfection with multiple pathogens was observed in 44.7% of patients (n = 127). Diarrheagenic Escherichia coli was the most commonly detected pathogen (30.6%, n = 87), followed by adenovirus (26.4%, n = 75), rotavirus (16.9%, n = 48), Shigella sp. (16.5%, n = 47), Giardia duodenalis (14.4%, n = 41), norovirus GII (7.0%, n = 20), sapovirus (5.6%, n = 16), Salmonella enterica (4.9%, n = 14), astrovirus (4.6%, n = 13), Campylobacter jejuni/coli (4.6%, n = 13), bocavirus (2.8%, n = 8), and norovirus GI (2.8%, n = 8). Our study provides useful information on the possible causes of diarrheal diseases affecting children in southeastern Gabon. A similar study with a control group of healthy children is needed to assess the burden of the disease attributed to each pathogen.

Diarrhea illness in livestock keeping households in Cambodia: An analysis using a One Health framework

BackgroundMost of human diarrheal pathogens are zoonotic, and transmission of the pathogens can occur by contaminated food, water, environment and direct contact with animals especially for livestock keepers. Yet little is known of the relative importance of different risk factors especially in under-studied countries. The objectives of this study were to identify risk factors for diarrhea in livestock keepers in Cambodia and detect diarrhea-causing pathogenic bacteria in both humans and livestock within a One Health approach. Of special interest were the links between diarrhea and food consumption and livestock-keeping.Materials and methodsWe used an existing dataset from a questionnaire survey conducted in 400 livestock farms in Prey Veng and Kampot Prefectures between February and March 2013 as well as laboratory results on bacterial isolation from fecal and swab samples from livestock and poultry, and human stool samples. Laboratory results were available for up to three animals of each species kept by a household, and for up to three human samples from households reporting at least one case of human diarrhea in the previous 2 weeks. Presence of Escherichia coli, Shigella spp. and Salmonella spp. was investigated in both animal and human samples, in addition to Aeromonas spp., Vibrio spp. and Plesiomonas spp. in animal samples and Campylobacter spp. in human samples. Univariable and multivariable risk factor analyses were performed by generalized linear mixed model.ResultsHousehold-level diarrhea incidence rate was 9.0% (36/400). The most statistically significant factor associated with diarrhea in multivariable analysis was water treatment for drinking and cooking (OR = 0.33, 95%CI: 0.16–0.69, p = 0.003), followed by number of days consuming egg within 2 weeks (OR = 1.16, 95%CI: 1.04–1.29, p = 0.008), number of children under 5 years old (OR = 1.99, 95%CI: 1.14–3.49, p = 0.016) and keeping poultry (OR = 0.36, 95%CI: 0.14–0.92, p = 0.033). Animal samples for bacterial culture test were collected at 279 cattle, 165 pig and 327 poultry farms, and bacteria were detected from 6 farms with the isolation of Escherichia coli O157 (non H7) from 1 cattle and 1 pig sample, Aeromonas caviae from 1 pig sample and Salmonella spp. from 3 chicken samples. In human samples, 17 out of 67 individual samples were positive for the culture test, detecting Escherichia coli O157 (non H7) from 7 samples and Shigella spp. from 10 samples. None of the households where target bacteria were detected from animal samples had human samples collected due to lack of diarrhea episodes in the household.ConclusionsIt has often been hypothesized that keeping livestock may increase the incidence of diarrhea through multiple pathways. Contrary to this, we found livestock-keeping was not associated with increased risk, but food-related behavior and children under 5 years of age were strongly associated with increased risk. We discuss mediating and confounding factors and make recommendations for reducing the burden of diarrheal disease in Cambodia and more widely in low- and middle-income countries.

Diarrhoeal pathogens in the stools of children living with HIV in Ibadan, Nigeria.

Diarrhoea can be debilitating in young children. Few aetiological investigations in Africans living with human immunodeficiency virus (HIV) have been performed since antiretrovirals became widely available. Stool specimens from children with diarrhoea living with HIV, and HIV-uninfected controls, recruited at two hospitals in Ibadan, Nigeria, were screened for parasites and occult blood, and cultured for bacteria. Following biochemical identification of at least five colonies per specimen, diarrhoeagenic Escherichia coli and Salmonella were confirmed by PCR. Data were line-listed and comparisons were made using Fisher's Exact test. Only 10 children living with HIV could be enrolled during the 25-month study period and 55 HIV-uninfected children with diarrhoea were included for comparison. The most common pathogens overall were enteroaggregative E. coli (18/65, 27.7%), enteroinvasive E. coli (10/65, 15.4%), Cryptosporidium parvum (8/65, 12.3%) and Cyclospora cayetanensis (7/65, 10.8%). At least one pathogen was detected from seven of ten children living with HIV and 27 (49.1%) HIV-uninfected children. Parasite detection was associated with HIV positive status (p=0.03) with C. parvum specifically recovered more commonly from children living with HIV (p=0.01). Bacterial-parasite pathogen combinations were detected in specimens from four of ten children living with HIV but only 3(5.5%) HIV-uninfected children (p=0.009). Stools from five of ten children living with HIV and 7(12.7%) HIV-negative children (p = 0.014) contained occult blood. Even though children living with HIV present infrequently to Ibadan health facilities with diarrhoea, their greater propensity for mixed and potentially invasive infections justifies prioritizing laboratory diagnosis of their stools.

Seasonal variation of diarrhoeal pathogens among Guinea-Bissauan children under five years of age.

Diarrhoea remains a major cause of childhood morbidity and mortality in low-income countries (LICs). The frequency of diarrhoeal episodes may vary by season, yet few prospective cohort studies have examined seasonal variation among various diarrhoeal pathogens using multiplex qPCR to analyse bacterial, viral and parasitic pathogens. We combined our recent qPCR data of diarrhoeal pathogens (nine bacterial, five viral and four parasitic) among Guinea-Bissauan children under five years old with individual background data, dividing by season. The associations of season (dry winter and rainy summer) and the various pathogens were explored among infants (0-11 months) and young children (12-59 months) and those with and without diarrhoea. Many bacterial pathogens, especially EAEC, ETEC and Campylobacter, and parasitic Cryptosporidium, prevailed in the rainy season, whereas many viruses, particularly the adenovirus, astrovirus and rotavirus proved common in the dry season. Noroviruses were found constantly throughout the year. Seasonal variation was observed in both age groups. In childhood diarrhoea in a West African LIC, seasonal variation appears to favour EAEC, ETEC, and Cryptosporidium in the rainy and viral pathogens in the dry season.

The transmembrane domains of the type III secretion system effector Tir are involved in its secretion and cellular activities.

Enteropathogenic Escherichia coli (EPEC) is a diarrheagenic pathogen and one of the major causes of gastrointestinal illness in developing countries. EPEC, similar to many other Gram-negative bacterial pathogens, possesses essential virulence machinery called the type III secretion system (T3SS) that enables the injection of effector proteins from the bacteria into the host cytoplasm. Of these, the translocated intimin receptor (Tir) is the first effector to be injected, and its activity is essential for the formation of attaching and effacing lesions, the hallmark of EPEC colonization. Tir belongs to a unique group of transmembrane domain (TMD)-containing secreted proteins, which have two conflicting destination indications, one for bacterial membrane integration and another for protein secretion. In this study, we examined whether TMDs participate in the secretion, translocation, and function of Tir in host cells. We created Tir TMD variants with the original or alternative TMD sequence. We found that the C-terminal TMD of Tir (TMD2) is critical for the ability of Tir to escape integration into the bacterial membrane. However, the TMD sequence was not by itself sufficient and its effect was context-dependent. Moreover, the N-terminal TMD of Tir (TMD1) was important for the postsecretion function of Tir at the host cell. Taken together, our study further supports the hypothesis that the TMD sequences of translocated proteins encode information crucial for protein secretion and their postsecretion function.

Prevalence of Some Diarrhea Pathogens among under 5, in Wad Medani Pediatric Teaching Hospital, Gezira State, Sudan

Infections of gastrointestinal tract are the most frequent diseases worldwide. Infectious diarrhea is a major public health problem and remains one of the most important causes of morbidity and mortality among infants and children especially in developing countries. The symptoms of gastroenteritis include diarrhea and vomiting which may lead to severe dehydration and even death. The aim of this study was to identify some diarrheal pathogen among under five children attending to wad Medani Pediatric Teaching hospital during January 2021 to march 2022. Total of 384 stool samples were collected from children suffering from diarrhea and were tested using culture with biochemical test, direct examination by wet preparation and staining techniques. Moreover, screen Rotavirus by Ag ICT were used to determine their prevalence. The data were collected using questionnaire and analyzed using Statistical Package for the Social Sciences (SPSS). The results showed that the prevalence of pathogens were 196 samples (51%). The prevalence of pathogens showed that (29.6 %) was Giardia lamblia, (19.9%) was Cryptosporidium, (13.3%) was Rotaviruses, (12.2%) was Escherichia coli,( 9.7%) was Schigella species,( 8.7%) was Entamoeba histolytica and (6.6% )was Salmonella species. From those infected patients,( 56.1%) had fever, (76%) had vomiting. Also, (39.3%) were resides in urban while( 60.7%) resides in rural situation. About (42.9 % )had severe dehydration, (60% )acute diarrhea and (40%) chronic diarrhea , (87.8%) of children was take Rota vaccine and (70%) of mother not use soap to cleaning the children and think diarrhea not infectious disease it cause by teething. In conclusion most of diarrhea cause by parasitic infections mostly in poor family that not able to provide safety water and sanitation and low education of mother also some children suffer from malnutrition which decrease immunity and give chance to infection (Cryptosporidium).&#x0D; In Recommendation, health education about diarrhea disease in child important for mother to prevention, attention should be Payed proper to hygienic measure such as hand washing, safe disposal of feces and disinfection of contaminated surface to reduce the risk of infections agents transmission.

Co-existence of Extended Spectrum β-Lactamase and carbapenemase-producing genes from Diarrheagenic Enteric pathogens isolated in a tertiary care hospital.

Multiple drug resistance (MDR) among bacterial pathogens is a growing concern that clinicians are facing worldwide. Diarrhea among infants is frequent and is caused by various bacterial and viral infectious agents. Two hundred and twelve stool specimens were collected from pediatric patients from a rural quaternary hospital in Barshi, Sholapur, India, between March and December 2017. Total 180 specimens were positive for various bacterial pathogens, while the remaining 32 diarrhea cases may have been caused by a viral or uncultured bacterial pathogen. Identification of the bacterium and its antibiotic susceptibility were primarily carried out with VITEK-2. Distribution of diarrhea-causing bacteria among the 180 samples was as follows: 61.11% (110) Escherichia coli, 30.55% (55) Klebsiella pneumoniae, 4.44% (8) Proteus mirabilis, 2.22% (4) Shigella spp. 1.11% (2) Morganella morganii and 0.55% (1) each for Enterobacter cloacae and Citrobacter koseri. There was a co-existence of multiple genetic traits conferring extreme drug resistance (XDR) status to 19 isolates, 17 of which were determined to be E. coli and one each of E. cloacae and C. koseri. Antibiotype determination using VITEK-2 and polymerase chain reaction (PCR) amplification of the genetic traits indicated the co-existence of blaTEM and blaCTX-M15 isolates in all 19 isolates, with the exception of E. cloacae. Results showed that 10 out of 19 strains expressed the AmpC cephalosporinase blaCMY-2 gene, whereas metallo-carbapenemase was expressed in four isolates. Distribution of blaNDM-11 and acquired penicillinase blaSHV-1 resistance among 180 clinical isolates is discussed in the light of ESBL traits. This is the first report from the rural part of Maharashtra India showing that as many as 10.55% of the pathogenic strains were XDR, a step ahead of MDR.

Molecular characterization of Arcobacter butzleri isolates from poultry in rural Ghana.

In recent years, Arcobacter butzleri has gained clinical significance as an emerging diarrheagenic pathogen associated with poultry and water reservoirs. The full clinical significance of Arcobacter remains rather speculative due to variable virulence and antibiotic susceptibility of individual strains. The aims of the present study were (i) to identify antibiotic resistance genes (ARGs) in the genome sequences of two multidrug-resistant A. butzleri isolates, (ii) to use multilocus-sequence typing (MLST) to generate a guiding phylogeny of A. butzleri isolates collected in Kumasi, Ghana, (iii) to examine the distribution of ARGs in the test cohort, and (iv) to assess the strain's virulence and possible antibiotic treatment options for arcobacteriosis based on the genome sequences and the ARG distribution. A total of 48A. butzleri isolates obtained from poultry were included in the analysis. These isolates were genotyped by MLST and the antibiotic susceptibilities of isolates to ampicillin, ciprofloxacin, tetracycline, gentamicin, and erythromycin were tested by disk diffusion. Whole genome sequence data of two multidrug-resistant (MDR) A. butzleri isolates were obtained by a combination of single-molecule real-time (SMRT) and Illumina sequencing technology. A total of 14 ARGs were identified in the two generated genome sequences. For all 48 isolates, the frequency of these 14 ARGs was investigated by PCR or amplicon sequencing. With 44 different sequence types found among 48 isolates, strains were phylogenetically heterogeneous. Four of 48 isolates showed an ARG constellation indicating a multidrug-resistant phenotype. The virulence genes in the two A. butzleri genomes showed that the species might be characterized by a somewhat lower virulence as Campylobacter species. The phenotypic susceptibility data combined with the distribution of the particular ARGs especially oxa-464 and the T81I point mutation of the quinolone resistance determining region (QRDR) in a significant percentage of isolates indicated that macrolides and tetracycline can be recommended for calculated antibiotic treatment of arcobacteriosis in Ghana, but not ampicillin and quinolones.

Butyrate Differentiates Permissiveness to Clostridioides difficile Infection and Influences Growth of Diverse C. difficile Isolates.

A disrupted "dysbiotic" gut microbiome engenders susceptibility to the diarrheal pathogen Clostridioides difficile by impacting the metabolic milieu of the gut. Diet, in particular the microbiota-accessible carbohydrates (MACs) found in dietary fiber, is one of the most powerful ways to affect the composition and metabolic output of the gut microbiome. As such, diet is a powerful tool for understanding the biology of C. difficile and for developing alternative approaches for coping with this pathogen. One prominent class of metabolites produced by the gut microbiome is short-chain fatty acids (SCFAs), the major metabolic end products of MAC metabolism. SCFAs are known to decrease the fitness of C. difficile in vitro, and high intestinal SCFA concentrations are associated with reduced fitness of C. difficile in animal models of C. difficile infection (CDI). Here, we use controlled dietary conditions (8 diets that differ only by MAC composition) to show that C. difficile fitness is most consistently impacted by butyrate, rather than the other two prominent SCFAs (acetate and propionate), during murine model CDI. We similarly show that butyrate concentrations are lower in fecal samples from humans with CDI than in those from healthy controls. Finally, we demonstrate that butyrate impacts growth in diverse C. difficile isolates. These findings provide a foundation for future work which will dissect how butyrate directly impacts C. difficile fitness and will lead to the development of diverse approaches distinct from antibiotics or fecal transplant, such as dietary interventions, for mitigating CDI in at-risk human populations. IMPORTANCE Clostridioides difficile is a leading cause of infectious diarrhea in humans, and it imposes a tremendous burden on the health care system. Current treatments for C. difficile infection (CDI) include antibiotics and fecal microbiota transplant, which contribute to recurrent CDIs and face major regulatory hurdles, respectively. Therefore, there is an ongoing need to develop new ways to cope with CDI. Notably, a disrupted "dysbiotic" gut microbiota is the primary risk factor for CDI, but we incompletely understand how a healthy microbiota resists CDI. Here, we show that a specific molecule produced by the gut microbiota, butyrate, is negatively associated with C. difficile burdens in humans and in a mouse model of CDI and that butyrate impedes the growth of diverse C. difficile strains in pure culture. These findings help to build a foundation for designing alternative, possibly diet-based, strategies for mitigating CDI in humans.

Antibody-functionalized, stimuli responsive microgel gold-hybrid colloids: synthesis, characterizations and their use in pathogen detection

Antibody-functionalized hybrid microgels serve as an innovative approach for various translational applications particularly for detection of pathogens. We have synthesized Poly (N-isoproplyacrylamide)-co-poly(acrylic acid) (PNIPAm-PAA) based microgels encapsulated with gold nanoparticles followed by loading on antibodies specific to diarrheal pathogen, Salmonella typhimurium using the established streptavidin-biotin chemistry. Antibody-loaded hybrid microgel particles are further characterized with respect to their loading efficiencies using UV-Vis spectrometry and pH/temperature-dependent swelling using dynamic light scattering. Our results showed that streptavidin-coated hybrid gold nanoparticles bind to biotinylated antibodies with high affinity. From UV-Vis spectroscopy, it was observed that antibody-conjugated PNIPAM-AuNS showed two peaks; one at a wavelength of 540 nm due to gold nanoparticles and another at a wavelength of 280 nm due to antibodies. The effect of temperature on the hydrodynamic radius (Rh) of PNIPAM microgel particles, PNIPAM-AuNS, streptavidin-coated PNIPAM-AuNS and biotinylated antibodies conjugated with PNIPAM-AuNS was determined by dynamic light scattering which was further confirmed from the temperature dependant swelling of these biotinylated antibodies loaded onto hybrid microgels which exhibit less thermoresponsivity than the control hybrid microgels. Our results establish stimuli-responsive polymer hybrids as important new hybrid biomaterials for the detection of Salmonella typhimurium.

Occurrence of Diarrheagenic Pathogens and Their Coinfection Profiles in Diarrheic Under Five Children and Tracked Human Contacts in Urban and Rural Settings of Eastern Ethiopia.

Diarrheagenic Escherichia coli, Campylobacter, Nontyphoidal Salmonella, and Shigella are common cause of childhood diarrhea in countries like Ethiopia, but data on their sources and coinfection profiles is limited. A cross sectional study was conducted from November 2021 to January 2023 to determine the prevalence, coinfection, and monthly occurrence rates of major diarrheagenic bacteria in diarrheic under five children and asymptomatic contacts at urban and rural settings in Ethiopia. A total of 345 stool samples were collected from; 262 diarrheic children visiting Hiwot Fana Hospital, Kersa, and Adelle Health Centers; and 83 caretakers and siblings through case based contact tracing. Samples were analyzed using standard laboratory procedures and the overall prevalence of enteric pathogens was 26.96%, with the highest isolation rate during the winter and peaks of 73.91% in February. The occurrence of the pathogens in children and tracked contacts was 27.86 and 24.09%, respectively. In our study, 8.53% coinfection and 23.66% single pathogen infection was recorded in diarrheic children. The study also showed 4.51 and 3.88% of diarrhea in children from urban and rural had attributed to bacterial coinfection, respectively. The most prevalent pathogen in diarrheic children was Diarrheagenic E. coli (10.31%), and followed by Campylobacter. On the other hand, Diarrheagenic E. coli was the second dominant bacteria following Shigella in the traced contacts, with prevalence of 8.43% and 9.64%, respectively. Based on the study site, the prevalence of Diarrheagenic E. coli and Nontyphoidal Salmonella was higher in children from urban than those from rural. However, the occurrence of each pathogen had no significant differences (P > .05) between settings. The high pathogens occurrence rate in the current study indicates the need for strong control strategies and better child carrying and treatment of diarrheal diseases at both urban and rural settings. Further studies on possible sources and factors attributing to the occurrence of enteric pathogens in children are also recommended.

Probing of an Appreciable Antimicrobial Compound Producing Lactobacillus Strain from Milk Products of Thanjavur Region, Tamil Nadu and its Enhanced Production

ABSTRACT: Lactobacillus is a heterogeneous class of lactic acid strains that synthesize bioactive compounds which contribute many health benefits to our mankind. Focusing this view, different Lactobacillus strains were collected from dairy products and were screened for their bioactive efficiencies against an infant diarrheal bacterial pathogen. 11 morphologically unique Lactobacillus strains were procured from curd, yoghurt and buttermilk purchased from the Thanjavur region, Tamil Nadu, India. While screening on a microtiter plate-based test, YMP3 revealed the best antimicrobial activity against a human pathogenic Vibrio cholerae with 67.8±2.1% inhibition. Further, the most appreciable strain was molecularly identified as Lactobacillus apis YMP3 based on 16S rRNA sequencing methodology. Based on the growth kinetics profile, this strain showed maximum production of antimicrobial compound between 72 to 108hrs of incubation. Furthermore, this strain evidenced the cultural conditions of pH 6.5 and 35°C temperature for the appreciable production of the antimicrobial compound. Based on these overall observations, the research stood as the promising baseline data for the enhanced antimicrobial investigation of this probiotic L. apis YMP3 against many human pathogenic strains and its possibilities for drug development.

Plant-derived nanoparticles as alternative therapy against Diarrheal pathogens in the era of antimicrobial resistance: A review.

Diarrhea is a condition in which feces is discharged from the bowels frequently and in a liquid form. It is one of the frequent causes of morbidity and mortality in developing countries. The impact of Diarrhea is worsened by the increasing incidence of antimicrobial resistance among the causative agents, and this is now categorized as a global healthcare challenge. Antimicrobial resistance among Diarrheal pathogens also contributes to extended infection durations, and huge economic loss even in countries with advanced public health policies. The ever-increasing incidence of antimicrobial resistance including the contraindications arising from the administration of antibiotics in some Diarrheal cases highlights a crucial need for the development of novel non-antibiotic alternative agents for therapeutic and biocontrol applications. One such intervention includes the application of plant-derived nanoparticles (PDNPs) with novel antimicrobial properties. Given their small size and large surface area to volume ratio, PDNPs can attack target bacterial cell walls to generate reactive oxygen species that may simultaneously disrupt bacteria cell components such as DNA and proteins leading to cell damage or death. This potential can make it very difficult for pathogenic organisms to develop resistance against these antibacterial agents. In this review, we provide a critical overview on the antimicrobial resistance crisis among Diarrheagenic bacteria. We also discuss the evidence from the existing literature to support the potential associated with the use of PDNPs as alternative therapeutic agents for multidrug resistant and antibiotics administer contraindicated bacteria that are associated with Diarrhea.