Enterobacteriaceae Research Articles

Genome-wide screen of genetic determinants that govern Escherichia coli growth and persistence in lake water.

Although enteric bacteria normally reside within the animal intestine, the ability to persist extraintestinally is an essential part of their overall lifestyle, and it might contribute to transmission between hosts. Despite this potential importance, few genetic determinants of extraintestinal growth and survival have been identified, even for the best-studied model, Escherichia coli. In this work, we thus used a genome-wide library of barcoded transposon insertions to systematically identify functional clusters of genes that are crucial for E. coli fitness in lake water. Our results revealed that inactivation of pathways involved in maintaining outer membrane integrity, nucleotide biosynthesis, and chemotaxis negatively affected E. coli growth or survival in this extraintestinal environment. In contrast, inactivation of another group of genes apparently benefited E. coli growth or persistence in filtered lake water, resulting in higher abundance of these mutants. This group included rpoS, which encodes the general stress response sigma factor, as well as genes encoding several other global transcriptional regulators and RNA chaperones, along with several poorly annotated genes. Based on this co-enrichment, we identified these gene products as novel positive regulators of RpoS activity. We further observed that, despite their enhanced growth, E. coli mutants with inactive RpoS had reduced viability in lake water, and they were not enriched in the presence of the autochthonous microbiota. This highlights the duality of the general stress response pathway for E. coli growth outside the host.

Food safety in Latin American informal food establishments

Background and aimInformal food establishments are an important source of food due to their increased affordability of products and convenience. Food security and safety are two key factors that must coexist for a proper functioning of the food system. In Latin America, the safety of food is less analyzed than food security, although it is central to people’s health, as well as to their personal sustainability. Since informal food establishments are popular food sources in Latin America, this research aims to examine the presence of foodborne pathogens in food products from such establishments.MethodsThis research will be conducted as narrative literature review, collecting data from all publications in Spanish-speaking countries in Latin America between January 1, 2018, and May 31, 2023. The databases searched were PubMed and Web of Science. The search included pathogens such as bacteria, parasites and viruses. The languages of the articles assessed were English and Spanish.ResultsThe analysis was based on 32 articles focusing on seven of all Spanish-speaking countries in Latin America. The pathogens found belonged either to a bacteria type, or to a parasite. No viruses were investigated within the selection of articles. The widest variety of pathogens was among bacteria. The most frequently identified bacteria belonged to the family Enterobacteriaceae. The food products examined ranged from animal products to fruit and vegetables, fish, seafood and already-prepared dishes or juices. The informal food establishments where the studies conducted their analyses were markets, backyard selling points, street establishments or convenience food stores.ConclusionIdentifying pathogens in food products commercialized at different informal retail points has impacts for the safety of the food from personal sustainability viewpoint. Therefore, efforts need to be directed toward better support of the informal food sector in their provision of safe food. Further investigation could trace the exact sources of infection, while public health officials can implement safety programs in cooperation with food vendors.

Isolation and Identification of Bacterial Contamination Water Supply in Shendi City-Sudan

Background: Microbial contamination of water persists to be a significant problem; the usual source is human and animal fecal matter that has contaminated the water systems. The presence of bacteria and pathogenic organisms is of great concern when considering the safety of drinking water, as pathogenic organisms can cause watery diarrhea, cholera, typhoid fever, and other illnesses. Objective: This is a prospective tap water examination study to find groundwater microbiological fecal contamination. Materials and Methods: Water samples for laboratory examination were collected from a different area of Shendi city, which were classified as Tap water. Each sample was a collection in a sterile container and then isolated and Confirmation by biochemical test. Results: Tap water samples were found to be contaminated with E. coli about 80 (63.6%) samples, an indicator of contamination with the fecal matter of animals and humans. It was the isolation of other Gram-negative enteric bacteria such as Salmonella and pseudomonas these were not scientific indicators of water contamination by animal and human fecal matter. Conclusions: Tap Water was contaminated with feces and posed a health risk to consumers of that water and was found to be contaminated with E.coli bacteria. Future studies are needed to understand the complicated issues concerning water quality in the city. Community-led sanitation and hygiene education and better water source protection are urgently required.

Enteric Bacterial Infections, Antimicrobial Susceptibility Pattern, Intestinal Parasites, and Associated Factors Among Food Handlers in Yabelo Town, Borena Zone, Southern Ethiopia.

Foodborne illnesses are the main cause of morbidity and mortality in the twenty-first century, and food handlers are the main source of these illnesses. The study aimed to assess the prevalence of intestinal parasites, enteric bacteria, antimicrobial susceptibility patterns, and associated factors among food handlers working in a food and drinking establishment in Yabelo town, Borena zone, Southern Ethiopia, in 2022. A facility-based cross-sectional study design was employed to assess the food handler's state of health. Data were gathered using semistructured questionnaires and observational checklists, and 396 regular stool samples were collected. Samples were examined with microscopy and bacteriological culture to isolate enteric bacteria. Statistical Package for the Social Sciences, version 26 The factors that had a P-value of <.05 were considered statistically significant. Of the 396 stool samples collected, 164 (41.4%) were tested positive for intestinal parasites, while 40 (10.1%) were positive for enteric bacteria (Salmonella and Shigella). Among intestinal parasites, the most predominant parasite was Ascaris lumbricoides 48 (12.1%). All isolates of Salmonella and Shigella showed resistance to ampicillin. In multivariable analysis, not trimming fingernails regularly (AOR = 2.02, 95% CI 1.97-5.37), not washing hands with soap after the toilet (AOR = 3.02, 95% CI 2.37-5.62), and eating raw food (AOR = 2.1, 95% CI 1.79-6.51) have a significant association with the prevalence of bacteria and parasites. The majority of food handlers had poor hygiene practices, and the prevalence of parasites and bacteria was high in the study setting. Educational status, eating raw vegetables or fruit, hand washing after the toilet, and fingernail trimming have associations with the health status of food handlers.

Broad specificity of monoclonal IgA (TEPC15-IgA) for enteric bacteria via phosphorylcholine-mediated interaction.

Immunoglobulin A (IgA) is notable for its broad specificity toward multiple bacteria. Phosphorylcholine (PC) plays a role in the infection of pathogenic bacteria carrying PC and in the induction of IgA responses in the host immune system. The commercially available mouse monoclonal IgA, TEPC15-IgA, is a distinctive antibody with specificity for PC, warranting further exploration of its response to PC-bearing enteric bacteria. In this study, using 17 different enteric bacteria, including 3 aerobic and 14 anerobic bacteria that could be cultured in vitro, we confirmed that TEPC15-IgA recognizes 4 bacterial species: Lactobacillus taiwanensis, Limosilactobacillus frumenti, Streptococcus infantis, and Escherichia coli, although reactivity varied. Interestingly, TEPC15-IgA did not react with four of six Lactobacillus species used. Moreover, distinct target molecules associated with PC in L. taiwanensis and L. frumenti were evident, differing in molecular weight. These findings suggest that the natural generation of PC-specific IgA could prevent PC-mediated infections and potentially facilitate the formation of a microflora rich in indigenous bacteria with PC, particularly in the gastrointestinal tract.

Klebsiella pneumoniae Antibiotic Resistance Pattern Towards Antimicrobial Agents in Urinary Tract Infection Patients in Zawia City / Libya

Urinary Tract Infections (UTIs) represent a significant public health concern, contributing to serious health issues, extensive antibiotic use globally, and ranking as the second most common reason for clinical consultations in community settings. Various bacteria, particularly from the Enterobacteriaceae family, including Klebsiella spp., are implicated in the etiology of UTIs. This study focused on assessing the prevalence and antibiotic resistance patterns of uropathogenic K. pneumoniae across different age groups and genders. A total of 819 urine samples were collected from patients visiting Zawia hospitals and clinics between September 2022 and February 2023. Identification of K. pneumoniae was performed through colony morphology, Gram staining, and biochemical assays, followed by antibiotic susceptibility testing. Out of all samples, 271 (33.07%) exhibited significant bacterial growth. The incidence of UTIs was notably higher in females (40.15%) compared to males (20.6%). The age group of 1-9 years showed the highest susceptibility to UTIs at 35.4%. K. pneumoniae accounted for 23.9% of all UTI cases, with a higher prevalence in males (31.14%) than in females (21.9%). The 1-9 year age group was identified as the most vulnerable to K. pneumoniae infections, with a prevalence of 29.2%. K. pneumoniae demonstrated a high susceptibility rate of 86.2% to Meropenem, while showing significant resistance to Tetracycline at 70.8%. The findings indicate a high prevalence of UTIs in the 1-9 year age group, with females at greater risk. Males exhibited a higher susceptibility to K. pneumoniae, particularly in the younger age group. The bacterium showed strong sensitivity to Meropenem and considerable resistance to Tetracycline. Increased awareness and regular monitoring of antimicrobial usage in healthcare settings are essential to mitigate resistance rates and combat this pathogen.

Detection of Carbapenemase Producing Gram-negative Bacteria at a Tertiary Care Hospital: A Cross-sectional Study

Introduction: Gram-negative bacteria have developed a broad spectrum of resistance due to antibiotic degradation enzymes, including Extended-spectrum Beta-lactamases (ESBL), AmpC β-lactamases, and carbapenemases. Carbapenemase- producing organisms, such as Escherichia coli, Klebsiella species, Acinetobacter species, and Pseudomonas species, have become one of the most important causes of nosocomial and community-acquired infections. Aim: To identify carbapenemase-producing organisms among Multidrug-resistant (MDR) clinical isolates and detect Metallo β-Lactam Carbapenemases (MBL). Materials and Methods: The present study is a cross-sectional study that included 1266 clinical samples from patients visiting the Department of Microbiology, Ranagaraya Medical College, Kakinada, Andhra Pradesh, India. from July 2022 to December 2022. The samples were processed using the standard culture and antimicrobial susceptibility test, employing the Kirby-Bauer Disk Diffusion method. The present study included organisms that were resistant to either imipenem or meropenem. Carbapenemases were detected using the Modified Hodge test (MHT), and MBL carbapenemases were detected using the Imipenem Ethylene Diamine Tetraacetic acid (EDTA) Double Disk Test (DDT) following the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Descriptive statistics were performed on the collected data. Results: The study samples comprised 842 (66.5%) Gram- negative isolates and 424 (33.5%) Gram-positive isolates. Among the Gram-negative isolates, 80 (9.5%) were carbapenem- resistant, of which MHT showed 56 (70%) positive isolates (carbapenemase-producing) and 24 (30%) negative isolates. Imipenem-EDTA DDT showed 50 (62.5%) positive isolates (MBL-producing) and 30 (37.5%) negative isolates. Conclusion: Carbapenemase production in Gram-negative organisms has reduced the clinical utility of the carbapenem group of drugs, posing a major challenge in the treatment of severe infections. In summary, the majority of carbapenem-resistant isolates in the present study were from the Enterobacteriaceae family. These isolates were subjected carbapenem-resistant isolates to MHT and DDT tests to identify carbapenemase and metallo-beta-lactamase-producing strains that were resistant to a wide spectrum of antibiotics. The present study enables the early detection of these MDR strains, ensuring appropriate management.

Isolation and Identification of Pathogenic Bacteria from Commercially Marketed Fish in Wukari, North-Eastern Nigeria

Abstract Pathogenic bacteria that are part of the natural microflora can be found in aquaculture products. Microbial pathogens associated with fish can be transmitted to humans who consume or handle the fish. This study aimed to isolate human pathogenic bacteria present in the gills, intestine and skin of apparently healthy and spoil fishes. Tilapia (Oreochromisniloticus) and Cat fish (Clariaslazera) were collected from Wukari old market and Yam market of Wukari Nigeria. Bacteria were isolated from the fish gill, intestine and skin. The growth properties of distinct isolates on specific culture media were used to differentiate and characterize them. Pathogenic bacteria were recovered from various fish species that appeared with different features. The following human pathogenic bacteria were isolated; Escherichia coli and Staphylococcus aureus. The total bacteria count value ranges between 0.12 x 105 to 3.52 x 105 for the tilapia fish and 0.12 x 105 to 3.96 x 105 cfu/ml for cat fish. The identification revealed that Staphylococcus aureus and Escherichia coli was the most abundant pathogenic bacteria and also present in the initial water samples collected. Presence of Staphylococcus aureus and Eshcherichia coli is attributed to contamination of the fish samples by man through handling and processing. These enteric bacteria in fish serve as indicator organisms of faecal contamination and or water pollution. Their presence also represents a potential hazard to humans’ life. The isolates were higher from Yam market samples compared to Wukari old market.

Design of dot-blot hybridization assay for simultaneous detection of Campylobacter jejuni and Campylobacter coli: a preliminary study.

Campylobacters are a major cause of gastroenteritis worldwide. These are fastidious in culture and false negative results are seen in many clinical laboratories. Among molecular methods, the dot-blot technique is widely used for a variety of purposes, especially diagnostics. So, the authors aimed to detect C. jejuni and C. coli simultaneously using a dot-blot assay. After evaluating the bioinformatics studies, a cadF-conserved fragment was selected for the design of primers and probe. DNAs from standard strains and a recombinant plasmid, prepared in this study, were used to assess the technique. The specificity of the method was also surveyed using DNAs from other enteric bacteria. The limit of detection was evaluated by recombinant plasmid and different concentrations of the designed probe. A 95-bp fragment of cadF was selected, and in silico analysis studies showed that it is conserved between both species. Also, the non-specific annealing of the primers and probe with other bacteria was not seen theoretically. The technique with recombinant plasmid as well as DNAs of standard strains created black spots on the membrane, confirming that the probe was correctly synthesized. No non-specific reactions with other bacterial species were observed (specificity=100%). The limit of detection of the test was determined to be 50µg/ml. This is the first study to simultaneously detect two important pathogens in the Campylobacter genus and was able to detect C. jejuni and C. coli with acceptable sensitivity and specificity.

Synthesis and biological evaluation of lipid A derived from commensal Bacteroides.

The inflammation-inducing properties of lipopolysaccharides (LPS) of Gram-negative bacteria reside in their lipid A moiety. Bacillus fragilis, which is a commensal Gram-negative bacterium, biosynthesises lipid A that is structurally distinct from that of E. coli and other enteric bacteria. It is composed of a β1,6-linked glucosamine (GlcN) disaccharide that is only phosphorylated at the anomeric center. The major species of B. fragilis has five fatty acids and the amine of the distal GlcN moiety carries the unusual (R)-3-(13-methyltetradecanoyloxy)-1.5-methylhexadecanoic acid. A recent study indicates that the LPS of B. fragilis has anti-viral activity by selective induction of interferon (IFN)-β and is protective in mouse models of vesicular stomatitis virus (VSV) and influenza A. Heterogeneity in the structures of LPS and lipid A and possible contamination with other inflammatory components make it difficult to unambiguously define the immune-modulatory properties of LPS or lipid A. Therefore, we developed a synthetic approach for the preparation of the unusual major lipid A species derived from B. fragilis, which includes a synthetic approach for (R)-3-(13-methyltetradecanoyloxy)-1.5-methylhexadecanoic acid by the Wittig olefination to install the terminal isopropyl moiety. The proinflammatory and antiviral responses of synthetic B. fragilis lipid A were investigated in several cell lines and primary human monocytes by examining the production of interleukin (IL)-6 and IFN-β. It was found that B. fragilis does not induce the production of IL-6 and IFN-β but can partially antagonize the production of pro-inflammatory cytokines induced by E. coli LPS and lipid A.

Evaluation of 5'-End Phosphorylation for Small RNA Stability and Target Regulation In Vivo.

Bacterial small RNAs (sRNAs) can be equipped at the 5' end with triphosphate (5'PPP) or monophosphate (5'P) groups, depending on whether they are primary transcripts, undergo dephosphorylation or originate via processing. Often, 5' groups hallmark RNAs for rapid decay, but whether this also applies to sRNAs is little explored. Moreover, the sRNA 5'P group could activate endoribonuclease RNase E to cleave the base-paired target RNA, but a tool for investigation in vivo was lacking. Here, we describe a two-plasmid system suitable for the generation of 5' monophosphorylated RNAs on demand inside the cell. The sRNA gene of interest is fused to the 3' end of a fragment of sRNA GlmZ and transcribed from a plasmid in an IPTG-inducible manner. The fusion RNA gets cleaved upon arabinose-controlled expression of rapZ, provided on a compatible plasmid. Adaptor protein RapZ binds the GlmZ aptamer and directs RNase E to release the sRNA of choice with 5'P ends. An isogenic plasmid generating the same sRNA with a 5'PPP end allows for direct comparison. The fates of the sRNA variants and target RNA(s) are monitored by Northern blotting. This tool is applicable to E. coli and likely other enteric bacteria.

Gut Akkermansia muciniphila, Prevotellaceae, and Enterobacteriaceae spp. as Possible Markers in Women-Related Nutritional and Clinical Trials: Familial Mediterranean Fever Disease.

Studies have shown that the gut microbiota of healthy men and men with familial Mediterranean fever (FMF) disease respond differently to placebo. Given the fact that the composition of the gut microbiota is different in men and women, this study aimed to describe in detail the placebo response of the gut microbiota in healthy and FMF women. The bacterial response to placebo was fully evaluated on a previous PhyloChip™ DNA microarray-based assay (GEO Series; accession number GSE111835). The change in the total number of operational taxonomic units in healthy women exposed to placebo is more than that of healthy men, in contrast to FMF people (704 vs. 140 and 409 vs. 7560, respectively [p < 0.05]). Gut Firmicutes diversities are more sensitive to placebo, whereas Akkermansia muciniphila remained unchanged after the placebo administration for both healthy and FMF people. Gut Prevotellaceae and Enterobacteriaceae diversities of healthy subjects and FMF women are also almost unchanged from placebo. Meanwhile, only 56.35% of gut Enterobacteriaceae diversities in FMF men were placebo resistant. The response to a placebo varies depending on a person's gender and health status. Healthy and FMF women's placebo study groups could be avoided by excluding placebo-sensitive 704 of 18,725 and 409 of 18,725 bacterial diversities, respectively. Because the placebo causes changes in all gut bacterial phyla in healthy and FMF women, and only the representatives of Enterobacteriaceae and Prevotellaceae families and A. muciniphila spp. are not affected by placebo, these bacteria can be considered as possible markers in women-related nutritional/clinical trials. Data on the response of the gut microbiota in healthy women to placebo might be used in studies of diseases other than FMF. The response of gut bacteria from different taxonomic affiliations to placebo may provide a basis for uncovering the role of these bacteria in the gut-brain axis.

Prevalence and antimicrobial resistance of Enterobacteriaceae in the north of Kazakhstan.

An increasing number of drugs are used each year in the treatment of small pets (cats and dogs), including medicines (cephalosporins and fluoroquinolones) used in human therapy. The purpose of this study was to isolate and explore the antibiotic resistance of opportunistic Enterobacteriaceae (Escherichia coli, Klebsiella, Proteus, Ci trobacter, Enterobacter) from cats and dogs, and to isolate resistance genes in the microorganisms. In 2021, 808 samples of biological material from small domestic animals were collected in veterinary clinics in Kostanay. From these, 210 microorganisms were isolated and identified. A large majority of the strains sampled belonged to E. coli-149 (70.9%), Enterobacter-11 (5.2%), Klebsiella-28 (13.3%), Proteus-12 (5.7%) and 10 Citrobacter isolates (4.8%). In all isolates identified, antibiotic resistance/sensitivity was determined by disc-diffusion method to ampicillin, cefoxitin, gentamicin, levomycetin, tetracycline, ciprofloxacin, norfloxacin, ofloxacin, cefoperazone, cefpodoxime, streptomycin, kanamycin, doxycycline, gemifloxacin, nalidixic acid, furazolidone, furadonine, amoxicillin, and enrofloxacin. The study has demonstrated that the greatest number of Enterobacteriaceae were sensitive to the action of meropenem, which belongs to the group of beta-lactam antibiotics; resistance was demonstrated against tetracycline, doxycycline, ampicillin, amoxicillin, ofloxacin, and cefpodoxime. The most common genes encoding antimicrobial resistance were as follows: BlaTEM and OXA in 41 and 28 isolates, respectively, encoding resistance to beta-lactams; StrA and StrB in 45 and 48 isolates encoding aminoglycosides; and tetA and tetB in 43 and 28 isolates encoding tetracyclines. Obtained data demonstrate that uncontrolled and frequent use of beta-lactam and tetracycline antibacterials, in cats and dogs, results in the spread of genotypic resistance among micro-organisms of the family Enterobacteriaceae.

Bird species (Charadriiformes) does not impact endosymbiotic bacteria (Gammaproteobacteria) of their ectoparasites (Insecta: Phthiraptera: Ischnocera)

Endosymbiotic bacteria of insects can facilitate host expansion into novel niches by providing their host with a fitness benefit such as vitamins or amino acids that are otherwise lacking in their hosts' diet. This close association can lead to cospeciation between insects and their symbionts; however, the symbionts’ small genome size leaves it susceptible to genome derogation which can result in symbiont replacement. Here, we screen chewing lice infesting shorebirds and terns to see what endosymbiotic bacteria are present, and build a summary phylogeny that includes louse endosymbiont sequences from this study as well as those from other louse genera, insects and bacteria strains from GenBank. We found a Sodalis-allied endosymbiont in Carduiceps, Lunaceps, Quadraceps, and Saemundssonia, as well as symbionts belonging to the family Enterobacteriaceae in Lunaceps, and Quadraceps. No louse species were host to both endosymbionts; however, the birds Kentish Plover (Charadrius alexandrinus) and Greater Crested Tern (Thalasseus bergii) were host to two genera of lice, each of which was infested with a different group of endosymbionts. In the summary phylogeny the endosymbionts from shorebirds, and tern lice did not form a monophyletic group, and therefore likely acquired their bacterial endosymbionts multiple times.

Methods of identification of phytopathogenic bacteria Pectobacterium carotovorum subsp. carotovorum

Bacterial infections are a global problem. The most common pathogens of infections among gram-negative bacteria are representatives of the Enterobacteriaceae family. Pectobacterium are gram-negative phytopathogenic bacteria belonging to the Enterobacteriaceae family.The purpose of the study is to develop methods for the identification of phytopathogenic bacteria. At the capacity of test components of developed identification algorithm, we used the data presented in the reference «Bergey’s Manual of Systematics of Archaea and Bacteria». research parameters and for selection of Model microorganisms bacteriological tests were reference strains of Pectobacterium carotovorum B-3455 obtained from the All-Russian collection of microorganisms and Pectobacterium carotovorum 333 from the collection of NRCEM Museum of FSBEI HE Ulyanovsk SAU named after P.А. Stolypin. From 50 samples of phytosanitary control and environmental objects, 5 strains were classified as Pectobacterium carotovorum spp. carotovorum.

Fermented Polyherbal Formulation Restored Ricinoleic Acid-Induced Diarrhea in Sprague Dawley Rats and Exhibited In Vitro Antibacterial Effect on Multiple Antibiotic-Resistant Gastrointestinal Pathogens.

The involvement of multiple antibiotic-resistant gastrointestinal pathogens in diarrhea aggravates the disease condition uncontrollably. The current study aimed to find and develop a suitable formulation utilizing multiple natural components from known plant sources to augment the current therapeutic outcomes. The hydroethanolic extraction method was applied through boiling and fermentation on ancient observation-based efficacious plant parts for developing the antidiarrheal polyherbal formulation AP-01. An animal study model of diarrhea was used to evaluate the safety and efficacy of the formulation. The formulation was tested in vitro on four different multiple antibiotic-resistant gastrointestinal pathogens collected from the national repository. The formulation depicted no cytotoxicity on normal gut cells and was efficacious at 10 ml/kg single dose in relieving symptoms of diarrhea by 79.71%, compared with the standard drug showing a reduction of symptoms by 83.01%. AP-01 exhibited delayed gastric motility. The symptoms of diarrhea ceased to occur within 320.66 ± 5.05 minutes with AP-01, whereas the standard drug took 308 ± 6.63 minutes. AP-01 was found successful at a viable dosage regimen of 75 μl/ml v/v to 100 μl/ml v/v in inhibiting the growth of different pathogens from the Enterobacteriaceae family possessing resistance against several classes of antibiotics in culture media. Chemical analysis revealed different alkaloids, flavonoids, and polyphenols that probably work in unison through multiple modes of action to arrest diarrhea and inhibit pathogens simultaneously. These promising results shown by AP-01 should evoke an effort to dive deep into research and development for better therapeutic formulations for infectious diarrhea by harvesting nature's arsenal.

Dominância da comunidade bacteriana em uma lagoa costeira eutrófica induzida por esgoto utilizando sequenciamento de nova geração: observações iniciais

Abstract: This study investigates the presence of bacterial dominance in one of the most studied sewage-driven eutrophic coastal lagoons, the Imboassica Lagoon in Macaé (RJ), Brazil, utilizing high-throughput sequencing of 16S rDNA. Water samples were collected from three sites within the lagoon. Total microbial DNA was extracted, and the V3-V4 region of the 16S rRNA gene was amplified and sequenced on the Illumina MiSeq platform. A total of 744,879 partial 16S rRNA sequences were clustered, revealing the absence of a single bacterial dominance in the sewage-driven eutrophic coastal lagoon. The prominent phyla detected in the lagoon were Cyanobacteria (27.8%), Proteobacteria (23.7%), and Actinobacteria (14.6%). Proteobacteria emerged as the most abundant phylum in the sewage-impacted lagoon site, whereas Cyanobacteria dominated the other two sampling sites. Among families, Synechococcaceae predominated with genus Synechococcus exhibited the highest prevalence. Families of potentially toxic Cyanobacteria represented less than 1% of the total families. The sewage-impacted lagoon section displayed greater bacterial diversity and richness. The dominance of bacterial communities associated with raw sewage, such as members of the Enterobacteriaceae family, was not confirmed, constituting only 0.75% of the families in the most affected site. This study presents the initial analysis of the bacterial community in the Imboassica Lagoon and suggests that dominance in the lagoon responds to the eutrophication and sewage discharge.

Microbial Diversity in Children with Gastroenteritis in the Amazon Region of Brazil: Development and Validation of a Molecular Method for Complete Sequencing of Viral Genomes.

Metagenomic sequencing is a powerful tool that is widely used in laboratories worldwide for taxonomic characterization of microorganisms in clinical and environmental samples. In this study, we utilized metagenomics to investigate comprehensively the microbial diversity in fecal samples of children over a four-year period. Our methods were carefully designed to ensure accurate and reliable results. Validated and analyzed were metagenomic data obtained from sequencing 27 fecal samples from children under 10 years old with gastroenteritis over a four-year period (2012-2016). The fecal specimens were collected from patients who received care at public health facilities in the northern region of Brazil. Sequencing libraries were prepared from cDNA and sequenced on the Illumina HiSeq. Kraken-2 was utilized to classify bacterial taxonomy based on the 16S rRNA gene, using the Silva rRNA database. Additionally, the Diamond program was used for mapping to the non-redundant protein database (NR database). Phylogenomic analyses were conducted using Geneious R10 and MEGA X software, and Bayesian estimation of phylogeny was performed using the MrBayes program. The results indicate significant heterogeneity among norovirus strains, with evidence of recombination and point mutations. This study presents the first complete genome of parechovirus 8 in the region. Additionally, it describes the bacterial populations and bacteriophages present in feces, with a high abundance of Firmicutes and Proteobacteria, including an increased proportion of the Enterobacteriaceae family. The presented data demonstrate the genetic diversity of microbial populations and provide a comprehensive report on viral molecular characterization. These findings are relevant for genomic studies in gastrointestinal infections. The metagenomic approach is a powerful tool for investigating microbial diversity in children with gastroenteritis. However, further studies are imperative to conduct genomic analysis of identified bacterial strains and thoroughly analyze antimicrobial resistance genes.

Exploration of Klebsiella aerogenes derived secondary metabolites and their antibacterial activities against multidrug-resistant bacteria.

As the effectiveness of current treatments against the development of antimicrobial resistance is declining, new strategies are required. A great source of novel secondary metabolites with therapeutics effects are the endophytic bacteria present in medicinal plants. In this study, Klebsiella aerogenes (an endophytic bacteria belonging to the Enterobacteriaceae family) was isolated from Kalanchoe blossfeldiana (a medicinal plant". The bacterial secondary metabolites were identified using GC-MS techniques. Furthermore, the antibacterial potentials were investigated against multi-drug resistance (MDR) Salmonella typhi and Staphylococcus aureus. The GC-MS chromatogram of K. aerogenes secondary metabolites extract displayed total of 36 compounds. Ethyl acetate extracts of K. aerogenes, showed mean zone of growth inhibition of 15.00 ± 1.00 against S. typhi and 7.00 ± 1.00mm against S. aureus, respectively. The extract demonstrated significant antibacterial effectiveness against S. typhi and moderate antibacterial efficacy against S. aureus, with minimum inhibitory concentration (MIC) values ranging from 0.089 to 0.39 mg/mL. The time-kill kinetics profile of the ethyl acetate extract against S. typhi revealed a decrease in the number of viable cells during the initial 5, 6, and 24 hours. Conversely, there was a sudden increase in viable cells up to 6 hours for S. aureus. The identified secondary metabolite with high percentage than others, benzeneethanamine exhibited favorable interactions (-7.2 kcal/mol) with the penicillin-binding protein (PBP2a) of S. aureus and (-7.5 kcal/mol) osmoporin (OmpC) of S. typhi, indicating its potential as a candidate for drug development against these MDR bacteria. This study reported for the first time, bacterial endophytes associated with K. blossfeldiana with antibacterial activities.

Uterine lavage microbiological composition of dairy subclinical endometritis

The article presents the data on the dairy cows’ uterine lavage microbial composition characteristics suffering from subclinical endometritis. Subclinical endometritis is accompanied by the normal microbiota composition changes in the cow uterus and the disease-causing and opportunistic microorganisms’ growth. To perform uterine contents lavage, polystyrene disposable pipettes connected to a 50 ml disposable syringe using a plastic adapter were used. Subclinical endometritis was diagnosed in 22 cows (17.19%). Sixty-one dairy cows out of 128 (47.66%) were healthy. Microorganisms of the Enterobacteriaceae family: E. coli, P. vulgaris, S. enteritidis, pathogenic streptococci: S. agalactiae, S. pyogenes and staphylococci: S. aureus, S. epidermidis were selected. The total microbial contamination of the lavage samples was 64.72±8.80 CFU/ml. The most common microorganisms were microorganisms of the Enterobacteriaceae family: E. coli, S. enteritidis and P. vulgaris with 2069 CFU /ml. Pathogenic streptococci amounted to 1989 CFU /ml and staphylococci to 1,579 CFU /ml.