Pathogen Colonization Research Articles

Nuclear effectors of plant pathogens: Distinct strategies to be one step ahead.

Nuclear effector proteins released by bacteria, oomycete, nematode, and fungi burden the global environment and crop yield. Microbial effectors are key weapons in the evolutionary arms race between plants and pathogens, vital in determining the success of pathogenic colonization. Secreted effectors undermine a multitude of host cellular processes depending on their target destination. Effectors are classified by their localization as either extracellular (apoplastic) or intracellular. Intracellular effectors can be further subclassified by their compartment such as the nucleus, cytoplasm or chloroplast. Nuclear effectors bring into question the role of the plant nucleus' intrinsic defence strategies and their vulnerability to effector-based manipulation. Nuclear effectors interfere with multiple nuclear processes including the epigenetic regulation of the host chromatin, the impairment of the trans-kingdom antifungal RNAi machinery, and diverse classes of immunity-associated host proteins. These effector-targeted pathways are widely conserved among different hosts and regulate a broad array of plant cellular processes. Thus, these nuclear sites constitute meaningful targets for effectors to subvert the plant defence system and acquire resources for pathogenic propagation. This review provides an extensive and comparative compilation of diverse plant microbe nuclear effector libraries, thereby highlighting the distinct and conserved mechanisms these effectors employ to modulate plant cellular processes for the pathogen's profit.

Crop microbiome responses to pathogen colonisation regulate the host plant defence

Crop microbiome responses to pathogen colonisation regulate the host plant defence

Variable and insidious respiratory infections: can they be prevented?

In the practice of a pediatrician, among all detected infectious diseases, acute respiratory infections (ARI) continue to lead. The causes of respiratory infections can be varied. Great importance is attached to the normal microflora, as one of the main regulatory factors that can ensure the adaptation of children to different living conditions, and is responsible for maintaining homeostasis and maturation of the immune system. It has now been established that a healthy oral microbiome is the key to somatic health, and one of the important components of anti-infective protection. Therefore, one of the promising areas for the prevention of respiratory infections is the use of oral probiotics. The article provides an overview of findings from the studies on the efficacy and safety of the probiotic strain Streptococcus salivarius K12 showing inhibitory activities against the main respiratory pathogens – Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis. S. salivarius K12 produces the bacteriocin-like inhibitory substance BLIS K12 (Bacteriocin-Like Inhibitory Substance), which plays an important role in maintaining the natural flora of the upper respiratory tract. It has been proven that the use of S. salivarius K12 results in a reduction of the level of pathogen colonization of the oropharyngeal mucosa, a rapid decline of the clinical symptoms of acute and chronic diseases of the ENT organs, and the prevention of acute respiratory diseases. The reason for this is that the intake of S. salivarius K12 increases the amount of interferon γ in saliva, stimulating the adaptive immunity against many viral infections. S. salivarius K12 is included in the clinical guideline on acute tonsillopharyngitis for the prevention of relapses, as well as the recovery of the normal biota of the oropharyngeal mucosa after disease.

Conjunctival sac microbiome in anophthalmic patients: Flora diversity and the impact of ocular prosthesis materials.

To explore the changes of bacterial flora in anophthalmic patients wearing ocular prosthesis (OP) and the microbiome diversity in conditions of different OP materials. A cross-sectional clinical study was conducted, involving 19 OP patients and 23 healthy subjects. Samples were collected from the upper, lower palpebral, caruncle, and fornix conjunctiva. 16S rRNA sequencing was applied to identify the bacterial flora in the samples. The eye comfort of each OP patient was determined by a questionnaire. In addition, demographics information of each participant was also collected. The diversity and richness of ocular flora in OP patients were significantly higher than that in healthy subjects. The results of flora species analysis also indicated that in OP patients, pathogenic microorganisms such as Escherichia Shigella and Fusobacterium increased significantly, while the resident flora of Lactobacillus and Lactococcus decreased significantly. Within the self-comparison of OP patients, compared with Polymethyl Methacrylate (PMMA), prosthetic material of glass will lead to the increased colonization of opportunistic pathogens such as Alcaligenes, Dermabacter and Spirochaetes, while gender and age have no significant impact on ocular flora. The ocular flora of OP patients was significantly different from that of healthy people. Abundant colonization of pathogenic microorganisms may have an important potential relationship with eye discomfort and eye diseases of OP patients. PMMA, as an artificial eye material, demonstrated potential advantages in reducing the colonization of opportunistic pathogens.

LC-QToF-Based Metabolomics Identifies Aberrant Tissue Metabolites Associated with a Higher-Fat Diet and Their 'Reversion to Healthy' with Dietary Probiotic Supplementation.

Over 33% of Americans are labeled as obese, leading the World Health Organization to designate obesity as a major public health problem. One consequence of obesity is the development of metabolic syndrome, a condition which has been correlated to an increased risk for developing cardiovascular disease and Type 2 diabetes. Prolonged ingestion of a higher-fat diet, one cause of obesity, results in alterations to the gut microbiome. These alterations are implicated to have a profound role in the evolution and progression of obesity-linked diseases. Probiotics are associated with positive health effects such as limiting pathogen colonization, aiding in digestion, and vitamin synthesis. Using Ossabaw pigs as a model for obesity, and in conjunction with our previous research, we performed an in-depth, nontargeted, metabolomic analysis on select organs to elucidate the effects of dietary supplementation with the probiotic Lacticaseibacillus paracasei. We focused our analysis on the effects of probiotic supplementation on a higher-fat (obesogenic) diet and a nutritionally balanced diet. Notably, our findings reveal that the brain cortex is highly sensitive to dietary influencers, and with probiotic supplementation, several aberrant metabolites associated with a higher-fat diet revert to healthy levels, thus demonstrating the potential for a probiotic intervention for obesity-linked disease.

Prospective Application of Nanoencapsulated Bacillus amyloliquefaciens on Broiler Chickens’ Performance and Gut Health with Efficacy against Campylobacter jejuni Colonization

Probiotics as novel antibiotics' substitutes are verified to provide barriers for hindering the colonization of enteric bacterial pathogens with nutritional benefits. For enhancement of the probiotics' effectiveness, their integration within nanomaterials is a paramount tool to support the progress of new compounds with functional features. Therefore, we addressed the impact of effective delivery of probiotics (Bacillus amyloliquefaciens) loaded nanoparticles (BNPs) on performance and Campylobacter jejuni (C. jejuni) shedding and colonization in poultry. Two hundred Ross broiler chickens were divided into four groups fed various BNP levels: BNPs I, BNPs II, BNPs III, and BNPs-free diets for 35 days. Nanoparticles delivery of probiotics within broiler diets improved growth performance as reflected by higher body weight gain and superior feed conversion ratio, especially in BNPs II- and BNPs III-fed groups. In parallel, the mRNA expression levels of digestive enzymes encoding genes (AMY2a, PNLIP, CELA1, and CCK) achieved their peaks in BNPs III-fed group (1.69, 1.49, 1.33, and 1.29-fold change, respectively) versus the control one. Notably, with increasing the levels of BNPs, the abundance of beneficial microbiota, such as Bifidobacterium and Lactobacillus species, was favored over harmful ones, including Clostridium species and Enterobacteriaceae. Birds fed higher levels of BNPs displayed significant improvement in the expression of barrier functions-linked genes including DEFB1, FABP-2, and MUC-2 alongside substantial reduction in cecal colonization and fecal shedding of C. jejuni. From the aforementioned positive effects of BNPs, we concluded their potential roles as growth promoters and effective preventive aids for C. jejuni infection in poultry.

Bacteriological study of wound infections and their antimicrobial susceptibility pattern of isolates from patients at shaafi hospital Mogadishu, Somalia

Background: Wound infection is one of the public health problems worldwide associated with the colonization of bacterial pathogens and resistance to commonly used antibiotics. The study aimed to identify the most common bacterial pathogens that cause wound infections and their antimicrobial susceptibility of isolates from patients at shaafi Hospital in Mogadishu, Somalia. Methods: This study was a descriptive cross-sectional design conducted from January to June - 2020 at shaafi Hospital in Mogadishu –Somalia. A total of 80 patients were taken from wound swab; all specimens were directly cultured on standard media, then Gram stain and Biochemical tests were also done antimicrobial susceptibility test was performed following Standards guidelines and procedures of (CLSI). Results: A total of 80 patients were taken from the wound swab; of these, 25 samples shown significant growth, isolating 38 bacteria strains. The most bacteria that isolated was Staphylococcus aureus 15 (39.47%), followed by Escherichia coli 12 (32%), Klebsiella pneumonia 8 (21%), Proteus Vulgaris 2 (5%), and Pseudomonas aeruginosa 1(3%). Staphylococcus aureus was entirely resistant to penicillin G, Ampicillin, and Methicillin, less sensitive to amoxicillin, and strongly sensitive to gentamicin. Moreover, All isolates of Escherichia coli, Klebsiella pneumonia, Proteus Vulgaris were sensitive to gentamicin and norfloxacin. In contrast, all isolates of Pseudomonas aeruginosa were resistant to gentamicin and norfloxacin. Conclusions: The study revealed that bacterial pathogens of wound infection were resistant to commonly used antibiotics in Mogadishu, Somalia, showing an increasing trend of antibiotic-resistant. The study suggested that timely diagnosis with antimicrobial susceptibility is necessary before prescribing appropriate antibiotics.

Plant Disease Resistance-Related Pathways Recruit Beneficial Bacteria by Remodeling Root Exudates upon Bacillus cereus AR156 Treatment.

The environmentally friendly biological control strategy that relies on beneficial bacterial inoculants to improve plant disease resistance is a promising strategy. Previously, it has been demonstrated that biocontrol bacteria treatments can change the plant rhizosphere microbiota but whether plant signaling pathways, especially those related to disease resistance, mediate the changes in rhizosphere microbiota has not been explored. Here, we investigated the complex interplay among biocontrol strains, plant disease resistance-related pathways, root exudates, rhizosphere microorganisms, and pathogens to further clarify the biocontrol mechanism of biocontrol bacteria by using plant signaling pathway mutants. Bacillus cereus AR156, which was previously isolated from forest soil by our laboratory, can significantly control tomato bacterial wilt disease in greenhouse and field experiments. Moreover, compared with the control treatment, the B. cereus AR156 treatment had a significant effect on the soil microbiome and recruited 35 genera of bacteria to enrich the rhizosphere of tomato. Among them, the relative rhizosphere abundance of nine genera, including Ammoniphilus, Bacillus, Bosea, Candidimonas, Flexivirga, Brevundimonas, Bordetella, Dyella, and Candidatus_Berkiella, was regulated by plant disease resistance-related signaling pathways and B. cereus AR156. Linear correlation analysis showed that the relative abundances of six genera in the rhizosphere were significantly negatively correlated with pathogen colonization in roots. These rhizosphere bacteria were affected by plant root exudates that are regulated by signaling pathways. IMPORTANCE Our data suggest that B. cereus AR156 can promote the enrichment of beneficial microorganisms in the plant rhizosphere by regulating salicylic acid (SA) and jasmonic acid (JA)/ethylene (ET) signaling pathways in plants, thereby playing a role in controlling bacterial wilt disease. Meanwhile, Spearman correlation analysis showed that the relative abundances of these beneficial bacteria were correlated with the secretion of root exudates. Our study reveals a new mechanism for SA and JA/ET signals to participate in the adjustment of plant resistance whereby the signaling pathways adjust the rhizosphere microecology by changing the root exudates and thus change plant resistance. On the other hand, biocontrol strains can utilize this mechanism to recruit beneficial bacteria by activating disease resistance-related signaling pathways to confine the infection and spread of pathogens. Finally, our data also provide a new idea for the in-depth study of biocontrol mechanisms.

Effects of β-glucan on Salmonella enterica serovar Typhimurium swine colonization and microbiota alterations

BackgroundThe 2017 Veterinary Feed Directive eliminated the use of medically important antibiotics for growth promotion of food animals; thus, alternative growth promoters are highly desirable by food animal producers to enhance animal health and reduce pathogen colonization, including the human foodborne pathogen Salmonella. β(1-3)(1-6)-d-glucan (β-glucan) is a soluble fiber with prebiotic characteristics; it has been shown to modulate immune and intestinal functions that strengthen swine resistance to health challenges such as bacterial infections when supplemented in the diets of growing pigs. The current study evaluated the effects of a β-glucan product on gut microbial community structure as well as Salmonella shedding and intestinal colonization.ResultsFive-week-old pigs were fed a β-glucan amended diet at 500 g/ton (n = 13) or a non-amended control diet (n = 14) for three weeks, followed by inoculation of the 27 pigs with 1 × 109 colony forming units of Salmonella enterica serovar Typhimurium strain UK1. While remaining on the respective diets, fecal samples collected at 2, 4, 7, and 16 days post-inoculation (dpi) were similar for Salmonella shedding counts between the two diets. At 16 dpi, Salmonella counts were significantly lower in the cecal contents of the β-glucan-fed pigs (P = 0.0339) and a trend towards a reduction was observed in the Peyer’s patches region of the ileum (P = 0.0790) compared to the control pigs. Pigs fed β-glucan for three weeks exhibited an increase in members of the Clostridia class in their fecal microbial communities, and after inoculation with Salmonella, several potentially beneficial microorganisms were enriched in the microbiota of β-glucan-fed pigs (Lactobacillus, Ruminococcaceae, Prevotellaceae, Veillonellaceae, Bifidobacterium and Olsenella).ConclusionAdministration of β-glucan altered the swine gut microbiome and reduced Salmonella colonization in the cecal contents.

High Abundance of Candidatus Arthromitus in Intestinal Microbiota of Seriolella violacea (Palm Ruff) under Reared Conditions

Intestinal microbiota has been involved in several processes that benefit the host, such as digestion, nutrient metabolism, resistance to pathogens colonization and immune function. In this study, we investigated the diversity, composition and functional prediction of microbiota of reared Seriolella violacea (palm ruff) in the same cohort sampled at different times (7-, 8- and 9-month-old). Microbial community structure analyses, using 16S rRNA amplicon sequencing, revealed that the intestinal microbiota was dominated by the phyla Firmicutes, Proteobacteria, Fusobacteria and Tenericutes. At the genus level, Candidatus Arthromitus was the most abundant in all sampled timepoints, representing in average 78% of the bacterial community (ranging from 18 to 98%), corresponding to segmented filamentous bacteria, which are interesting because they have been associated with the maturation of immune responses in the gut and protecting the host from bacterial infections. The comparisons of the intestinal microbiota among the three groups showed differences in abundance of bacterial taxa and also in alpha diversity indexes (Shannon and Simpson), as well as beta diversity metrics (weighted and unweighted UniFrac). Potential functions of the intestinal microbiota of palm ruff were retrieved using Philipin and Tax4fun and these analyses revealed high levels of genes for sugar metabolism. To our knowledge, this study represents the first description of the intestinal microbiota of S. violacea.

Genetic and phenotypic assessment of the antimicrobial activity of three potential probiotic lactobacilli against human enteropathogenic bacteria.

Lactobacilli are avid producers of antimicrobial compounds responsible for their adaptation and survival in microbe-rich matrices. The bactericidal or bacteriostatic ability of lactic acid bacteria (LAB) can be exploited for the identification of novel antimicrobial compounds to be incorporated in functional foodstuffs or pharmaceutical supplements. In this study, the antimicrobial and antibiofilm properties of Lactiplantibacillus pentosus L33, Lactiplantibacillus plantarum L125 and Lacticaseibacillus paracasei SP5, previously isolated form fermented products, were examined, against clinical isolates of Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Enteritidis and Escherichia coli. The ability of viable cells to inhibit pathogen colonization on HT-29 cell monolayers, as well as their co-aggregation capacity, were examined utilizing the competitive exclusion assay. The antimicrobial activity of cell-free culture supernatants (CFCS) was determined against planktonic cells and biofilms, using microbiological assays, confocal microscopy, and gene expression analysis of biofilm formation-related genes. Furthermore, in vitro analysis was supplemented with in silico prediction of bacteriocin clusters and of other loci involved in antimicrobial activity. The three lactobacilli were able to limit the viability of planktonic cells of S. aureus and E. coli in suspension. Greater inhibition of biofilm formation was recorded after co-incubation of S. enterica with the CFCS of Lc. paracasei SP5. Predictions based on sequence revealed the ability of strains to produce single or two-peptide Class II bacteriocins, presenting sequence and structural conservation with functional bacteriocins. The efficiency of the potentially probiotic bacteria to elicit antimicrobial effects presented a strain- and pathogen-specific pattern. Future studies, utilizing multi-omic approaches, will focus on the structural and functional characterization of molecules involved in the recorded phenotypes.

Over supplementation with vitamin B12 alters microbe-host interactions in the gut leading to accelerated Citrobacter rodentium colonization and pathogenesis in mice

BackgroundVitamin B12 supplements typically contain doses that far exceed the recommended daily amount, and high exposures are generally considered safe. Competitive and syntrophic interactions for B12 exist between microbes in the gut. Yet, to what extent excessive levels contribute to the activities of the gut microbiota remains unclear. The objective of this study was to evaluate the effect of B12 on microbial ecology using a B12 supplemented mouse model with Citrobacter rodentium, a mouse-specific pathogen. Mice were fed a standard chow diet and received either water or water supplemented with B12 (cyanocobalamin: ~120 μg/day), which equates to approximately 25 mg in humans. Infection severity was determined by body weight, pathogen load, and histopathologic scoring. Host biomarkers of inflammation were assessed in the colon before and after the pathogen challenge.ResultsCyanocobalamin supplementation enhanced pathogen colonization at day 1 (P < 0.05) and day 3 (P < 0.01) postinfection. The impact of B12 on gut microbial communities, although minor, was distinct and attributed to the changes in the Lachnospiraceae populations and reduced alpha diversity. Cyanocobalamin treatment disrupted the activity of the low-abundance community members of the gut microbiota. It enhanced the amount of interleukin-12 p40 subunit protein (IL12/23p40; P < 0.001) and interleukin-17a (IL-17A; P < 0.05) in the colon of naïve mice. This immune phenotype was microbe dependent, and the response varied based on the baseline microbiota. The cecal metatranscriptome revealed that excessive cyanocobalamin decreased the expression of glucose utilizing genes by C. rodentium, a metabolic attribute previously associated with pathogen virulence.ConclusionsOral vitamin B12 supplementation promoted C. rodentium colonization in mice by altering the activities of the Lachnospiraceae populations in the gut. A lower abundance of select Lachnospiraceae species correlated to higher p40 subunit levels, while the detection of Parasutterella exacerbated inflammatory markers in the colon of naïve mice. The B12-induced change in gut ecology enhanced the ability of C. rodentium colonization by impacting key microbe-host interactions that help with pathogen exclusion. This research provides insight into how B12 impacts the gut microbiota and highlights potential consequences of disrupting microbial B12 competition/sharing through over-supplementation.Graphical 5vuKG727Y2QSKPsq8nr33cVideo

Muc2-dependent microbial colonization of the jejunal mucus layer is diet sensitive and confers local resistance to enteric pathogen infection.

Intestinal mucus barriers normally prevent microbial infections but are sensitive to diet-dependent changes in the luminal environment. Here we demonstrate that mice fed a Western-style diet (WSD) suffer regiospecific failure of the mucus barrier in the small intestinal jejunum caused by diet-induced mucus aggregation. Mucus barrier disruption due to either WSD exposure or chromosomal Muc2 deletion results in collapse of the commensal jejunal microbiota, which in turn sensitizes mice to atypical jejunal colonization by the enteric pathogen Citrobacter rodentium. We illustrate the jejunal mucus layer as a microbial habitat, and link the regiospecific mucus dependency of the microbiota to distinctive properties of the jejunal niche. Together, our data demonstrate a symbiotic mucus-microbiota relationship that normally prevents jejunal pathogen colonization, but is highly sensitive to disruption by exposure to a WSD.

P230 Adalimumab in Crohn’s disease is protective against periodontitis based on a validated oral health questionnaire

Abstract Background Crohn’s disease (CD) is associated with a 3-4 fold increased risk of periodontitis compared to the general population1 though periodonitis is poorly recognised and diagnosed. Evidence from mouse models highlight an important link between oral and gut health. Periodontitis has been shown to lead to ectopic colonization of oral pathogens and oral Th17-T cells that activate lamina propria macrophages and exacerbate gut inflammation2. Very little is known about the patient demographics of those at risk of periodontitis. This study aimed to assess the risk factors for periodontitis in CD patients. Methods We conducted a cross-sectional study recruiting CD patients at UCLH through myCare, an online platform for patients linked to their clinical records. Patient data were obtained using EpicCare, a web-based electronic patient record database. Patient risk of periodontitis was determined using a previously validated oral health questionnaire3. Statistical tests were conducted using IBM SPSS Statistics 27. Results This single centre study included 89 CD patients; 54% female and median age of 40 (IQR 19-82). Patients predominantly identified as White British (56%). The majority had ileocolonic CD (51%) with non-stricturing/non-penetrating behaviour (70%) and were on biologic therapy (52%) (Tab 1). The oral health questionnaire identified 37% of CD patients at risk of periodontitis. There was no statistically significant association between periodontitis risk and age, gender, age at CD diagnosis, disease duration, CD phenotype, family history, body mass index (BMI) or smoking status. Current steroid, immunomodulator use and number of prior biologics also showed no association. Current use of adalimumab and ustekinumab were both independently correlated with risk of periodontitis (χ2 p=0.004 &amp; χ2 p=0.044, respectively). 90% of patients receiving adalimumab were not at risk of periodontitis (Fig 1). In contrast, 60% of patients on ustekinumab were at risk of periodontitis. Logistic regression analysis showed that patients receiving adalimumab were 86% less likely to be at risk of periodontitis compared to patients not receiving adalimumab (OR 0.14 (CI 0.029 - 0.633, p=0.011)). 75% of the adalimumab group was anti-TNF naïve, but no association was seen between prior biologic use and periodontitis risk (p=0.91). Conclusion The questionnaire has identified a third of patients who are at risk of periodontitis in the CD cohort. Adalimumab shows benefit in mitigating this risk and may be a drug of choice in patients with oral disease. The questionnaire is a helpful tool to identify and refer at-risk patients.

Integrating Transcriptomics and Metabolomics to Explore the Novel Pathway of Fusobacterium nucleatum Invading Colon Cancer Cells

Colorectal cancer (CRC) is a malignancy with a very high incidence and mortality rate worldwide. Fusobacterium nucleatum bacteria and their metabolites play a role in inducing and promoting CRC; however, no studies on the exchange of information between Fusobacterium nucleatum extracellular vesicles (Fnevs) and CRC cells have been reported. Our research shows that Fusobacterium nucleatum ATCC25586 secretes extracellular vesicles carrying active substances from parental bacteria which are endocytosed by colon cancer cells. Moreover, Fnevs promote the proliferation, migration, and invasion of CRC cells and inhibit apoptosis; they also improve the ability of CRC cells to resist oxidative stress and SOD enzyme activity. The genes differentially expressed after transcriptome sequencing are mostly involved in the positive regulation of tumor cell proliferation. After detecting differential metabolites using liquid chromatography-tandem mass spectrometry, Fnevs were found to promote cell proliferation by regulating amino acid biosynthesis in CRC cells and metabolic pathways such as central carbon metabolism, protein digestion, and uptake in cancer. In summary, this study not only found new evidence of the synergistic effect of pathogenic bacteria and colon cancer tumor cells, but also provides a new direction for the early diagnosis and targeted treatment of colon cancer.

COLONIZATION OF PATHOGENIC AEROBIC BACTERIA IN THE EXTERNAL EAR AND EFFECTS OF CERUMEN TYPES, AGE, AND GENDER ON COLONIZATION

Aims: The study aimed to study the prevalence of pathogenic aerobic bacteria colonization in the outer ear and to determine the prevalence of cerumen types among different ages and sex of selected individuals in Sana'a city. Also determined the effects of cerumen types, age, and sex on the incidence of pathogenic aerobic bacterial colonization. Methods: The current study was carried out in the Department of Medical Microbiology and ENT Department, Faculty of Medicine and Health Sciences, Sana’a University. The study proposal was permitted by the ethics committee of the Faculty. Written informed consent was taken from the chosen participants. Families of the study sample members residing in the various sectors of Sana'a city were visited at home in which participants were randomly selected from all age groups and sexes. Households were reviewed on time and clinical examination of the ear was done and results were recorded and ear swab samples were collected. The rapid visual identification of cerumen was performed. The culture samples were collected and transferred to the laboratory then culture and bacterial growth was identified by standard bacteriological methods. Results: The study included 246 healthy persons, 33.3% of them male and 66.7% were females. The age ranged from 1 -80 years with mean age equal to 34.2±18.7 years, 96.3% of the study subjects have the wet type and only 3.7% have the dry type of cerumen, 2.03% had impacted cerumen. The most prevalent isolate from the outer ear was Staphylococcus aureus with 35 strains (14.2%), followed by Psedumonas aureginosa with 14 strains (5.7%). Klebsiella spp, Streptococcus pyogenes and Hemophilus influenzae isolates were less frequent with 7 (2.8%), 6 (2.4%) and 5 (2.03%) isolates, respectively. Positive growth for bacterial pathogens was significantly associated with males (OR=1.8, p=0.03), ≤15 years group (OR=2.5, p=0.01), and dry-type cerumen (OR=8.9, p=0.001). Conclusion: There are two distinct and specific types of cerumen, wet and dry, of which the wet type appears to be the most common in Yemen, and of the subspecies of the wet type, honey brown was dominant. The present study concluded that some pathogenic bacteria that can cause otitis externa are naturally present in the normal external auditory canal. The most prevalent isolate was Staphylococcus aureus, followed by Psedumonas aureginosa, Klebsiella spp, Streptococcus pyogenes, and Hemophilus influenzae. Hence clinicians must find a history of any predisposing factors before interpreting laboratory culture reports. Peer Review History: Received: 4 November 2022; Revised: 8 December; Accepted: 5 January 2023, Available online: 15 January 2023 Academic Editor: Ahmad Najib, Universitas Muslim Indonesia, Indonesia, ahmad.najib@umi.ac.id Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, sansan4240732@163.com Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, amaka_mgbahurike@yahoo.com

Bacterial composition of a competitive exclusion product and its correlation with product efficacy at reducing Salmonella in poultry.

The mature intestinal microbiome is a formidable barrier to pathogen colonization. Day-old chicks seeded with cecal contents of adult hens are resistant to colonization with Salmonella, the basis of competitive exclusion. Competitive exclusion products can include individual microbes but are commonly undefined intestinal communities taken from adult animals and in commercial production is amplified in fermentator and sold commercially in freeze dried lots. While superior to single and multiple species probiotics, reducing Salmonella colonization by multiple logs, undefined products have limited acceptance because of their uncharacterized status. In this study, the bacterial composition of the master stock, preproduction seed stocks and commercial lots of a poultry competitive exclusion product, was defined by 16S rRNA sequence analysis, targeting the 16S rRNA variable region (V1-V3). The samples contained a diversity of genera (22-52 distinct genera) however, the commercial lots displayed less diversity compared to the seeds and the master stock. Community composition varied between seeds and the master stock and was not a good predictor of potency, in terms of log10 reduction in Salmonella abundance. While there was significant correlation in composition between seeds and their commercial lots, this too was a not a good predictor of potency. There was linear correlation between unclassified Actinobacteria, Peptococcus, and unclassified Erysipelotrichaceae, and Salmonella abundance (r 2 > .75) for commercial seeds. However, upon review of the literature, these three genera were not consistently observed across studies or between trials that examined the correlation between intestinal community composition and Salmonella prevalence or abundance.

Biofilms in Chronic Wound Infections: Innovative Antimicrobial Approaches Using the In Vitro Lubbock Chronic Wound Biofilm Model.

Chronic wounds have harmful effects on both patients and healthcare systems. Wound chronicity is attributed to an impaired healing process due to several host and local factors that affect healing pathways. The resulting ulcers contain a wide variety of microorganisms that are mostly resistant to antimicrobials and possess the ability to form mono/poly-microbial biofilms. The search for new, effective and safe compounds to handle chronic wounds has come a long way throughout the history of medicine, which has included several studies and trials of conventional treatments. Treatments focus on fighting the microbial colonization that develops in the wound by multidrug resistant pathogens. The development of molecular medicine, especially in antibacterial agents, needs an in vitro model similar to the in vivo chronic wound environment to evaluate the efficacy of antimicrobial agents. The Lubbock chronic wound biofilm (LCWB) model is an in vitro model developed to mimic the pathogen colonization and the biofilm formation of a real chronic wound, and it is suitable to screen the antibacterial activity of innovative compounds. In this review, we focused on the characteristics of chronic wound biofilms and the contribution of the LCWB model both to the study of wound poly-microbial biofilms and as a model for novel treatment strategies.

Differential Colonization of the Plant Vasculature Between Endophytic Versus Pathogenic Fusarium oxysporum Strains.

Plant xylem colonization is the hallmark of vascular wilt diseases caused by phytopathogens within the Fusarium oxysporum species complex. Recently, xylem colonization has also been reported among endophytic F. oxysporum strains, resulting in some uncertainty. This study compares xylem colonization processes by pathogenic versus endophytic strains in Arabidopsis thaliana and Solanum lycopersicum, using Arabidopsis pathogen Fo5176, tomato pathogen Fol4287, and the endophyte Fo47, which can colonize both plant hosts. We observed that all strains were able to advance from epidermis to endodermis within 3 days postinoculation (dpi) and reached the root xylem at 4 dpi. However, this shared progression was restricted to lateral roots and the elongation zone of the primary root. Only pathogens reached the xylem above the primary-root maturation zone (PMZ). Related to the distinct colonization patterns, we also observed stronger induction of callose at the PMZ and lignin deposition at primary-lateral root junctions by the endophyte in both plants. This observation was further supported by stronger induction of Arabidopsis genes involved in callose and lignin biosynthesis during the endophytic colonization (Fo47) compared with the pathogenic interaction (Fo5176). Moreover, both pathogens encode more plant cell wall-degrading enzymes than the endophyte Fo47. Therefore, observed differences in callose and lignin deposition could be the combination of host production and the subsequent fungal degradation. In summary, this study demonstrates spatial differences between endophytic and pathogenic colonization, strongly suggesting that further investigations of molecular arm-races are needed to understand how plants differentiate friend from foe. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Comparison of bacterial profile of gallbladder with gallstones from patients undergoing cholecystectomy due to complicated and uncomplicated cholelithiasis: changes in the epidemiological scenario.

cholelithiasis is a highly prevalent disease of the digestive system in the world. In Brazil, it is a routine condition, whose studies suggest a prevalence of around 10% of adults. Colonization of bile and gallstone pathogens can occur when there is bacterial stasis and proliferation. This proliferation is facilitated by the adhesion and biofilm formation capacity of some bacteria. There are also lithogenic processes that involve bacterial participation. Studies have shown changes in the microbiota of the gallbladder of patients undergoing cholecystectomy, which may impact empirical treatment with antibiotics. microbiological analyzes of the sonication fluid of the gallstones and of two samples with bile were performed. Identification and antimicrobial susceptibility testing were performed according to a standard routine. of the 34 patients, 76.4% were female. The age group was 48 years +/- 16.61. Acute cholecystitis occurred in 50% of cases. Bactobilia was evidenced in 32.1% of the cases. Klebisiella pneumoniae was noted as the most prevalent pathogen in acute cholecystitis; and Enterobacter sp, in cases of uncomplicated cholelithiasis. Greater sensitivity was obtained in the search for microorganisms in the sonication fluid samples of the stones in relation to the bile samples (p=0.0058). there was a higher prevalence of bactobilia in patients with acute cholecystitis compared to those with uncomplicated cholelithiasis. The use of sonication in bacterial investigation proved to be superior to the conventional method and can be considered.