Prevalence Of Bacterial Species Research Articles

Comparison of Carbapenem-Resistant Microbial Pathogens in Combat and Non-combat Wounds of Military and Civilian Patients Seen at a Tertiary Military Hospital, Philippines (2013–2017)

Bacterial wound infections are a danger to both military and civilian populations. The nature of injury and infection associated with combat related wounds are important in guiding antibiotic prophylaxis and empiric treatment guidelines. The isolates were screened for drug-resistance by the MicroScan Walkaway Plus System using either the Negative Breakpoint Combo Panel (NBCP) 30 or 34 or Positive Breakpoint Combo Panel (PBPC) 20 or 23. Isolates with a minimum inhibitory concentration (MIC) of ≥8 μg/mL to imipenem and/or meropenem were tested for both carbapenemase production using the CarbaNP test and real-time PCR to determine molecular resistance mechanisms. Plasmid conjugation analysis was performed to define potential for horizontal gene transfer. We characterized 634 bacterial wound isolates collected from September 2013 to December 2017 from patients seen at a Philippine military tertiary hospital presenting with combat or non-combat injuries [354 (military) and 280 (civilians)]. Staphylococcus aureus was the most predominant bacterial species isolated from wounds in both populations (104/634, 16%). A variety of Gram-negative bacterial species comprised 442/634 (70%) of the isolates identified, with the most prevalent shown to be Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter sp. Carbapenemase production was detected in 34/442 (8%) Gram-negative isolates. Testing for molecular resistance mechanisms showed 32/34 (17 military, 15 civilian) wound isolates were blaNDM positive and 2 were blaVIM positive, with the two blaVIM isolates found in the civilian population. Plasmid conjugation of 14 blaNDM and 2 blaVIM positive wound isolates representatives showed 2/16 (13%) produced E. coli J53 transconjugants (E. coli from a civilian; E. cloacae from a military). We describe in this study the wound bacterial and antibiotic resistance profile in the military (combat vs non-combat associated) and civilian population. We observed that, with the exception of Acinetobacter sp., resistance of prevalent Gram-negative bacterial species to imipenem or meropenem were not significantly different between the military and civilian populations. We also presented data on the prevalent bacterial species isolated from both combat and non-combat wounds in a military tertiary care hospital setting as well as the carbapenemase-encoding gene primarily responsible for carbapenem resistance as well as evidence of horizontal transfer via mobile genetic elements. Clinicians may use this information to guide empiric antibiotic coverage for the predominant organisms if wound culture results are not readily available.A prospective, longitudinal evaluation of the wound bacterial profile documenting the changing bacterial flora using higher resolution molecular strategies can provide a more comprehensive understanding of the diversity, composition, and abundance of bacterial composition of the wound microbial community from the time of injury, during the course of evacuation from the field to higher level of care facilities, and up to wound resolution.

Staphylococcus aureus Biofilm Infection Compromises Wound Healing by Causing Deficiencies in Granulation Tissue Collagen.

The objective of this work was to causatively link biofilm properties of bacterial infection to specific pathogenic mechanisms in wound healing. Staphylococcus aureus is one of the four most prevalent bacterial species identified in chronic wounds. Causatively linking wound pathology to biofilm properties of bacterial infection is challenging. Thus, isogenic mutant stains of S. aureus with varying degree of biofilm formation ability was studied in an established preclinical porcine model of wound biofilm infection. Isogenic mutant strains of S. aureus with varying degree (ΔrexB > USA300 > ΔsarA) of biofilm-forming ability were used to infect full-thickness porcine cutaneous wounds. Compared with that of ΔsarA infection, wound biofilm burden was significantly higher in response to ΔrexB or USA300 infection. Biofilm infection caused degradation of cutaneous collagen, specifically collagen 1 (Col1), with ΔrexB being most pathogenic in that regard. Biofilm infection of the wound repressed wound-edge miR-143 causing upregulation of its downstream target gene matrix metalloproteinase-2. Pathogenic rise of collagenolytic matrix metalloproteinase-2 in biofilm-infected wound-edge tissue sharply decreased collagen 1/collagen 3 ratio compromising the biomechanical properties of the repaired skin. Tensile strength of the biofilm infected skin was compromised supporting the notion that healed wounds with a history of biofilm infection are likely to recur. This study provides maiden evidence that chronic S. aureus biofilm infection in wounds results in impaired granulation tissue collagen leading to compromised wound tissue biomechanics. Clinically, such compromise in tissue repair is likely to increase wound recidivism.

Genetic and Phylogenetic Diversity of Escherichia coli Strains Collected From Fecal Specimens of Patients Admitted to Zabol Hospitals

Introduction: Escherichia coli is one of the most prevalent bacterial species which cause gastrointestinal and digestive tract infections in humans and livestock. This study examined genotypic diversity of the E. coli isolates taken from fecal specimens in Zabol using random amplification of polymorphic DNA (RAPD) method and phylogenetic background.Materials and Methods: In this study, 100 isolates were collected from human samples and identified by the common biochemical tests. The isolates were categorized into four main phylogenetic groups including group A (28 isolates), group B1 (7 isolates), group B2 (48 isolates), and group D (17 isolates). Two primers (H1 & H2) were used to study the genetic variation of E. coli and the electrophoresis band pattern was analyzed by the NTSYS.Results: The analysis of the difference in isolates using the RAPD technique showed a genetic similarity between 14% and 100%.Conclusion: The phylogenetic groups B2 and A were more frequent in fecal isolates. In addition, the number of isolates related to phylogenetic groups B1 and D was significantly lower than that of the other groups.

Bacterial Microbiota and Metabolic Character of Traditional Sour Cream and Butter in Buryatia, Russia.

Traditional sour cream and butter are widely popular fermented dairy products in Russia for their flavor and nutrition, and contain rich microbial biodiversity, particularly in terms of lactic acid bacteria (LAB). However, few studies have described the microbial communities and metabolic character of traditional sour cream and butter. The objective of this study was to determine the bacterial microbiota and metabolic character of eight samples collected from herdsmen in Buryatia, Russia. Using single-molecule real-time (SMRT) sequencing techniques, we identified a total of 294 species and/or subspecies in 169 bacterial genera, belonging to 14 phyla. The dominant phylum was Firmicutes (81.47%) and the dominant genus was Lactococcus (59.28%). There were differences between the bacterial compositions of the sour cream and butter samples. The relative abundances of Lactococcus lactis, Lactococcus raffinolactis, and Acetobacter cibinongensis were significantly higher in sour cream than in butter, and the abundance of Streptococcus thermophilus was significantly lower in sour cream than in butter. Using a pure culture method, 48 strains were isolated and identified to represent seven genera and 15 species and/or subspecies. Among these isolates, Lactococccus lactis subsp. lactis (22.50%) was the dominant LAB species. Ultra-performance liquid chromatography–quadrupole–time of flight mass spectrometry at elevated energy was used in combination with statistical methods to detect metabolite differences between traditional sour cream and butter. A total of 27,822 metabolites were detected in all samples, and Lys-Lys, isohexanal, palmitic acid, Leu-Val, and 2′-deoxycytidine were the most dominant metabolites found in all samples. In addition, 27 significantly different metabolites were detected between the sour cream and butter samples, including short peptides, organic acids, and amino acids. Based on correlation analyses between the most prevalent bacterial species and the main metabolites in sour cream, we conclude that there may be a connection between the dominant LAB species and these metabolites. This study combined omics techniques to analyze the bacterial diversity and metabolic character of traditional sour cream and butter, and we hope that our findings will enrich species resource libraries and provide valuable resources for further research on dairy product flavor.

Microbiological air quality in office buildings equipped with dventilation systems.

Proper hygienic conditions in office buildings are of a high importance for both health and well-being of the employees. The aim of this study was the direct comparison of different ventilation systems on microbiological environments in 15 office buildings. The results showed that both bacterial and fungal concentrations in the naturally ventilated office buildings were between 70 and 1600cfu/m3 , while in the offices equipped with air-conditioning and mechanical ventilation systems, concentrations were lower, that is, between 10 and 530cfu/m3 and 20 and 410cfu/m3 , respectively. The size distribution analysis revealed that microorganisms were present in the air mainly as single cells (1.1-3.3μm) and large aggregates (4.7->7μm). If deposited in the human respiratory tract, they may be responsible for nose and eyes irritations, asthmatic reactions, and allergic inflammations. The most prevalent bacterial species indoors were Gram-positive cocci (mainly from Staphylococcus and Micrococcus/Kocuria genera) and endospore-forming Gram-positive rods (from Bacillus genus). Among the most common fungal species were those from genera Penicillium, Aspergillus, and Cladosporium. Effectively working and regularly maintained mechanical ventilation or air-conditioning systems ensure a better hygienic quality in the office buildings than natural/gravitational ventilation.

Abstract 5138: Comparative profiling for bacterial inhabitance in pancreatic ductal adenocarcinoma and matched adjacent normal tissues

Abstract Objective: Composition of resident microbes of the human body is associated with different disease manifestations. The microbiome in bodily fluids and different organs is altered with diverse health outcomes including cancer. Microbiome composition is a potential source for identifying biomarkers in cancers. Studies have shown the association of specific bacterial communities with the occurrence of pancreatic ductal adenocarcinoma (PDAC). However, investigations for the altered microbiota in an individual with the emergence of the disease are not studied. So, this study presents a comparative profiling for bacterial inhabitance in cancer tissues with that of matched adjacent normal tissues. This association will enable discovery of potential microbial biomarker(s) for PDAC. Methods: Fresh frozen cancer and matched adjacent normal (N= 20 each) tissues were collected from PDAC patients. Genomic DNA was extracted by MO BIO PowerSoil DNA Isolation kit and enriched using NEBNext Microbiome DNA Enrichment kit. Next-generation sequencing (NGS) method, pyrosequencing of 16S rRNA was used to assess the diversity of the tissue-associated microbiota. Operational Taxonomic Units (OTUs) were defined at >97% similarity followed by taxonomic classification using BLASTn against a curated GreenGenes/NCBI/RDP derived database (bTEFAP®). The Bray-Curtis coefficient was used to quantify the compositional dissimilarity between microbiome profiles. Statistical analysis was done using “R” and NCSS 2010. Alpha and beta diversity analyses were conducted to cluster samples by their microbiome profiles. Overall associations between PDAC and microbiome compositions were assessed based on weighted or unweighted UniFrac distances using PERMANOVA. Results: 16S taxonomic profiling reveal 10 and 11 dominant bacterial genera associated with normal and cancer lesion, respectively. Prominent genera that are only found in cancer lesions include Bacteroides, Enhydrobacter, Lautropia, Mycobacterium, and Phascolarctobacterium, whereas Fusobacterium, Acinetobacter, Propionibacterium, and Pseudomonas are the genera with high relative abundance in both cancer lesion and adjacent normal tissues. The most prevalent bacterial species in all observed samples are Propionibacterium acnes and Pseudomonas pseudoalcaligenes. We found Fusobacterium nucleatum in 4 samples (2 each in tumor and adjacent normal) in our preliminary work (10% prevalence). The PCoA multidimensional plot showed clustering of “tumor” samples, indicating the microbiota of these specimens is distinct from normal adjacent tissues. Conclusion: This study suggests a plethora of distinct bacterial community structure in PDAC lesions that is significantly different from that of matched adjacent normal tissues. Additionally, it suggests that the tissue-associated microbiota can serve as a useful biomarker for PDAC. Citation Format: Sheema S. Khan, Pratik Banerjee, Saini Setua, Daleniece Higgins, Satish Kedia, Yu Jiang, Meena Jaggi, Subhash Chauhan. Comparative profiling for bacterial inhabitance in pancreatic ductal adenocarcinoma and matched adjacent normal tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5138.

Effect of <i>Kaempferia parviflora</i> on <i>Streptococcus mutans</i> Biofilm Formation and its Cytotoxicity

Streptococcus mutans is the most prevalent bacterial species isolated from the human oral cavity. Its ability to form biofilms is an important factor in the pathogenesis of dental caries. Thus, the search for new antimicrobial agents, especially from plants, has been intensified. Kaempferia parviflora has been the subject of research for many pharmacological and antimicrobial activities. In this study, we evaluated the effect of ethanolic extract of K. parviflora root (0.46, 0.94, 1.87, 3.75, 7.5, 15, and 30 mg/ml) on S. mutans KPSK2 biofilm formation using crystal violet assay. Cytotoxicity was determined according to 10993-5/2009 on human gingival fibroblast by MTT assay. The results showed that K. parviflora extract could inhibit biofilm formation to approximately 62-82% at the concentrations of 0.46-30 mg/ml. In the case of cytotoxicity, no cytotoxic potential was demonstrated at concentration of £ 7.5 mg/ml of K. parviflora. In conclusion, K. parviflora extract is a potentially useful anti-biofilm agent against caries-associated bacteria and could be used as adjunct to other caries preventive measures.

Clinicopathologic and Microbiologic Findings Associated with Emphysematous Cystitis in 27 Dogs.

This is a retrospective case series of 27 dogs with emphysematous cystitis. Medical records from two veterinary teaching hospitals from 1992 to 2014 were reviewed. The aims of the study were to determine imaging findings, common underlying disease processes, and prevalent bacterial species and their antimicrobial susceptibility patterns in dogs with emphysematous cystitis. The most common lower urinary tract sign was hematuria. Gas was detected in the wall and lumen of the urinary bladder in 14 of 27 dogs (51.9%), in only the wall of the bladder in 9 of 27 dogs (33%), and in only the lumen of the bladder in 4 of 27 dogs (14.8%). Comorbid diseases were identified in all but one case. The most common comorbid disease processes were diabetes mellitus in 33% of dogs, neurologic disease in 26% of dogs, and adrenal disease in 19% of dogs. Bacterial isolates included Escherichia coli, Enterococcus spp., Klebsiella pneumoniae, Proteus mirabilis, Streptococcus spp., and Actinomyces spp. Enterococcus spp. were always isolated in mixed infections with gas-producing bacterial species. During the period of study, most isolates were predicted to be susceptible to beta-lactam drugs, but updated veterinary breakpoints suggest that fluoroquinolones or trimethoprim-sulfamethoxazole would be more appropriate choices for empiric therapy.

Prevalence of Bacillus sp. among the biofilm forming community on Ti surface in marine environment

Prevalence of bacterial species involved in biomineralization of manganese on titanium (Ti) surfaces in marine environment was revealed in this research work. This study involves one year sea water exposure of Ti and their periodical biofilm characterization was carried out to quantify the manganese oxidizing bacterial (MOB) presence in the biofilm formed on titanium surfaces. The total viable count study of Ti coupons exposed to sea water for one year resulted in 60% of the MOB in overall biofilm population. The biochemical characterization of MOB isolates were performed for the genus level identification of the seven bacterial isolates. Further, the seven strains were subjected to 16S rRNA gene sequencing. Evolutionary analysis was performed using MEGA 7 to obtain closely related strains within the groups. The manganese oxidizing ability of the bacterial isolates were determined with Leucoberbelin Blue Assay (LBB) and Atomic Absorption Spectroscopy studies (AAS). The results show that among the isolated marine MOB species, Bacillus sp. and Leptothrix sp. have the maximum Mn oxidizing property. The microtitre plate assay was performed to determine the biofilm forming ability of the isolated marine MOB species. All the results have confirmed the prevalence of Bacillus sp. among the biofilm colonizers on Ti surfaces when exposed in sea water.

Antimicrobial resistance development following surgical site infections.

Surgical site infections (SSIs) determine an increase in hospitalization time and antibiotic therapy costs. The aim of this study was to identify the germs involved in SSIs in patients from the Clinical Emergency County Hospital of Craiova (SCJUC) and to assess their resistance to antimicrobials, with comparisons between surgical wards and the intensive care unit (ICU). The biological samples were subjected to classical bacteriological diagnostics. Antibiotic resistance was tested by disc diffusion. We used hierarchical clustering as a method to group the isolates based upon the antibiotic resistance profile. The most prevalent bacterial species isolated were Staphylococcus aureus (S. aureus; 50.72%), followed by Escherichia coli (E. coli; 17.22%) and Pseudomonas aeruginosa; 10.05%). In addition, at lower percentages, we isolated glucose-non-fermenting, Gram-negative bacteria and other Enterobacteriaceae. The antibiotic resistance varied greatly between species; the most resistant were the non-fermenting Gram-negative rods. E. coli exhibited lower resistance to third generation cephalosporins, quinolones and carbapenems. By contrast, Klebsiella was resistant to many cephalosporins and penicillins, and to a certain extent to carbapenems due to carbapenemase production. The non-fermenting bacteria were highly resistant to antibiotics, but were generally sensitive to colistin. S. aureus was resistant to ceftriaxone (100%), penicillin (91.36%), amoxicillin/clavulanate (87.50%), amikacin (80.00%) and was sensitive to levofloxacin, doxycycline, gentamycin, tigecycline and teicoplanin. The Enterobacteriaceae resistance was only slightly higher in the ICU, particularly to carbapenems (imipenem, 31.20% in the ICU vs. 14.30% in the surgical wards; risk ratio = 2.182). As regards Staphylococcus species, but for non-fermenting bacteria, even if the median was almost the same, the antibiotic resistance index values were confined to the upper limit in the ICU. The data gathered from this study may help infection control teams to establish effective guidelines for antibiotic therapies in various surgical procedures, in order to minimize the risk of developing SSIs by the efficient application of the anti-infection armamentarium.

Distribution of various pathogenic bacteria from pediatric ward settings.

Objectives:To test various items in hospital environment as reservoirs of bacteria.Methods:This simple descriptive study was conducted between June and December 2014. Pediatric wards of 4 different hospitals of Faisalabad, Pakistan were selected and 8 different items per hospital were sampled (n=160). Poisson regression analysis was carried out with R software and using lme4 package.Results:There were no differences between the hospitals regarding total number of bacterial isolates or bacterial isolates per sample source or prevalent bacterial species. Utensile tables were significantly the least contaminated source when comparing all sample sources from all hospitals (p=0.05). When testing if the bacterial species differed significantly between sample sources, Escherichia coli (p=0.05) and Bacillus (p=0.04) were found significantly high on utensils, while Pseudomonas was found significantly less on curtains (p=0.03) and doors (p=0.02).Conclusion:Due to unhygienic practices in hospitals children are exposed to pathogens steers to life threatening infection. A good control strategy should be implemented to avoid health care-associated infection.

An integrated metagenomics pipeline for strain profiling reveals novel patterns of bacterial transmission and biogeography.

We present the Metagenomic Intra-species Diversity Analysis System (MIDAS), which is an integrated computational pipeline for quantifying bacterial species abundance and strain-level genomic variation, including gene content and single-nucleotide polymorphisms (SNPs), from shotgun metagenomes. Our method leverages a database of more than 30,000 bacterial reference genomes that we clustered into species groups. These cover the majority of abundant species in the human microbiome but only a small proportion of microbes in other environments, including soil and seawater. We applied MIDAS to stool metagenomes from 98 Swedish mothers and their infants over one year and used rare SNPs to track strains between hosts. Using this approach, we found that although species compositions of mothers and infants converged over time, strain-level similarity diverged. Specifically, early colonizing bacteria were often transmitted from an infant’s mother, while late colonizing bacteria were often transmitted from other sources in the environment and were enriched for spore-formation genes. We also applied MIDAS to 198 globally distributed marine metagenomes and used gene content to show that many prevalent bacterial species have population structure that correlates with geographic location. Strain-level genetic variants present in metagenomes clearly reveal extensive structure and dynamics that are obscured when data are analyzed at a coarser taxonomic resolution.

Antimicrobial resistance among aerobic biofilm producing bacteria isolated from chronic wounds in the tertiary care hospitals of Peshawar, Pakistan.

Chronic wound infections impose major medical and economic costs on health-care systems, cause significant morbidity, mortality and prolonged hospitalisation. The presence of biofilm producing bacteria in these wounds is considered as an important virulence factor that leads to chronic implications including ulceration. The undertaken study aimed to isolate and identify the biofilm aerobic bacterial pathogens from patients with chronic wound infections, and determine their antibiotics resistance profiles Method: During this study, swab specimens were collected from patients with chronic wounds at teaching hospitals of Peshawar, Pakistan between May 2013 and June 2014. The isolated aerobic bacterial pathogens were identified on the basis of standard cultural characteristics and biochemical tests. Antibiotics resistance profiles of biofilm producing bacteria against selected antibiotics were then determined. Among the chronic wound infections, diabetic foot ulcers were most common 37 (37%), followed by surgical ulcers 27 (27%). Chronic wounds were common in male patients older than 40 years. Among the total 163 isolated bacterial pathogens the most prevalent bacterial species were Pseudomonas aeruginosa 44 (27%), Klebsiella pneumoniae 26 (16%), Staphylococcus species 22 (14%) and Streptococcus spp. 21 (13%). The isolation rate of bacterial pathogens was high among patients with diabetic foot ulcers 83 (50.9%). Among bacterial isolates, 108 (66.2%) were observed as biofilm producers while 55 (33.8%) did not form biofilm in our model. The investigated biofilm producing bacterial isolates showed comparatively high resistance against tested antibiotics compared to non-biofilm producing bacterial isolates. The most effective antibiotics were amikacine and cefepime against all isolates. Increased multidrug resistance in biofilm producing bacteria associated with chronic wounds was observed in this study. Judicious use of antibiotics is needed to control the wound associated biofilm associated pathogens.

The Distribution of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Aggregatibacter actinomycetemcomitans in Patients with Alcoholic Disease: A Pilot Study.

Both drinking and periodontal disease are serious health and social problems. Findings on the effect of alcohol consumption on periodontal disease are inconclusive. The aim of this study was to evaluate, in patients with alcoholic disease, the composition of the main periopathogens: Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Aggregatibacter actinomycetemcomitans. The study was conducted on 25 alcoholics from the Department of Alcohol Addiction Closed Treatment and 25 non-alcoholic patients from the Department of Periodontology, Wroclaw Medical University. Subgingival biofilm samples were obtained from the 4 deepest sites (≥ 4 mm). The presence of 4 bacterial taxa was analysed using the PCR technique. The prevalence of bacterial species was significantly different between groups. Alcoholics showed significantly higher mean DNA counts for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Treponema denticola. In the qualitative analysis, no difference was observed between the groups. The study showed no statistically significant association between the amount of alcohol consumed and the composition of subgingival flora in patients suffering from alcoholism. Alcoholics demonstrated the presence of pathogenic bacteria in similar amounts to people diagnosed with chronic periodontal disease, but showed significantly higher mean DNA counts for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Treponema denticola but there is no correlation between the amount of alcohol consumption and the level of periopathogens.

Bacterial and fungal aerosols in the work environment of cleaners

Cleaning services are carried out in almost all sectors and branches of industry. Due to the above, cleaners are exposed to various harmful biological agents, depending on the tasks performed and the commercial sector involved. The aim of this study was to assess the exposure of cleaning workers to biological agents based on quantitative and qualitative characteristics of airborne microflora. A six-stage Andersen sampler was used to collect bioaerosols during the cleaning activities in different workplaces, including schools, offices, car services, healthy services and shops. Standard Petri dishes filled with blood trypticase soy agar and malt extract agar were used for bacterial and fungal sampling, respectively. The bioaerosol concentration values obtained during testing of selected workposts of cleaners were lower than the Polish recommended threshold limit values for microorganisms concentrations in public service. The most prevalent bacterial species in studied places were Gram-positive cocci (mainly of genera Micrococcus, Staphylococcus) and endospore-forming Gram-positive rods (mainly of genera Bacillus). Among the most common fungal species were those from genera Penicillium and Aspergillus. The size distribution analysis revealed that bioaerosols present in the air of workposts at shops, schools and car services may be responsible for nose and eye mucosa irritation and allergic reactions in the form of asthma or allergic inflammation in the cleaning workers. The study shows that occupational activities of cleaning workers are associated with exposure to airborne biological agents classified into risk groups, 1. and 2., according to their level of infection risk, posing respiratory hazard.

Comparative Genomics of the Genus Porphyromonas Identifies Adaptations for Heme Synthesis within the Prevalent Canine Oral Species Porphyromonas cangingivalis.

Porphyromonads play an important role in human periodontal disease and recently have been shown to be highly prevalent in canine mouths. Porphyromonas cangingivalis is the most prevalent canine oral bacterial species in both plaque from healthy gingiva and plaque from dogs with early periodontitis. The ability of P. cangingivalis to flourish in the different environmental conditions characterized by these two states suggests a degree of metabolic flexibility. To characterize the genes responsible for this, the genomes of 32 isolates (including 18 newly sequenced and assembled) from 18 Porphyromonad species from dogs, humans, and other mammals were compared. Phylogenetic trees inferred using core genes largely matched previous findings; however, comparative genomic analysis identified several genes and pathways relating to heme synthesis that were present in P. cangingivalis but not in other Porphyromonads. Porphyromonas cangingivalis has a complete protoporphyrin IX synthesis pathway potentially allowing it to synthesize its own heme unlike pathogenic Porphyromonads such as Porphyromonas gingivalis that acquire heme predominantly from blood. Other pathway differences such as the ability to synthesize siroheme and vitamin B12 point to enhanced metabolic flexibility for P. cangingivalis, which may underlie its prevalence in the canine oral cavity.

P03.14 High prevalence oflactobacillis crispatusamong adolescent girls attending secondary school in tanzania

Introduction Prevalence and incidence of HIV infection and other sexually transmitted infections (STIs) are particularly high among adolescent girls in sub-Saharan Africa. The role played by the vaginal microbiota in susceptibility to HIV and other STIs in adolescent girls is unclear. The aim of this study was to characterise the vaginal microbiota of adolescent girls in Tanzania around the time of their sexual debut. Methods Girls aged 17–18 years old attending secondary schools in Mwanza City were invited to join a cross-sectional study. After informed consent/assent, girls were interviewed and vaginal swabs were obtained and tested for the following species by in-house quantitative PCR: Lactobacillus crispatus, L. iners , L. gasseri, L. jensenii, L. vaginalis, Atopobium vaginae, and Gardnerella vaginalis . Differences in the prevalence of bacterial species were analysed using logistic regression. Results Of the 403 girls enrolled, 385 provided samples for this analysis. Of these, 163 reported having had sexual intercourse. Prevalences of bacterial species were as follows (overall; sexually active/sexually naive): L. crispatus (69%; 60%/75%), L. iners (83%; 85%/80%), L. gasseri (22%; 21%/23%), L. jensenii (49%; 40%/55%), L. vaginalis (66%; 55%/74%), A. vaginae (44%; 56%/34%), and G. vaginalis (62%; 75%/52%). Prevalences of A. vaginae and G. vaginalis were higher among girls who reported sexual intercourse (OR: 2.5; 95% CI: 1.7–3.8 and OR: 2.8; 95% CI: 1.8–4.4, respectively), while prevalences of L. crispatus, L. jensenii, and L. vaginalis were lower in sexually active girls (OR: 0.5; 95% CI: 0.3–0.8, OR: 0.5; 95% CI: 0.4–0.8, and OR: 0.4; 95% CI: 0.3–0.6, respectively). Conclusion Among girls attending secondary school in Tanzania, sexual debut was associated with quantifiable changes in vaginal microbiota. BV-associated bacteria were present in many girls before reported sexual debut. Additionally, the prevalence of L. crispatus was higher than expected; a recent study showed the prevalence among African women to be relatively low (17–38%). This challenges the view that women in sub-Saharan Africa have less L. crispatus colonisation. Disclosure of interest statement The authors do not have a conflict of interest. No pharmaceutical grants were received in the development of this study.

Studies of heavy metal contents and microbial composition of rhizosphere of <i>Panicum maximum</i> within and around auto mechanic workshop in Benin City

This study investigated the heavy metal content and microbial composition of rhizosphere of Panicum maximum obtained from some auto mechanic workshops in Benin City, Nigeria. The grass was uprooted and soil sample was taken from its rhizosphere. The sample were labeled appropriately and immediately transported into a polythene bag covered with aluminium foil papers. It was then taken to the laboratory for heavy metals and microbial assay. The results showed that average plant density of Panicum maximum per 100m2 of sampled subplots in the mechanic workshops was 8.50 in Ikpoba-Okha and 9.00 in Oredo, compared to 27.50 in the control. Fe content of rhizospheric soil in Ikpoba-Okha was 1527.6 mg/kg and 1653.1 mg/kg in Egor, compared to 1002.2 mg/kg in the control. Mean heavy metal content of rhizospheric soils was 11.71 mg/kg of Mn, 0.031 mg/kg of Pb, and 9.98 mg/kg of Cr. Total hydrocarbon content ranged from 1445.0 – 2314.2 mg/kg in the oil-polluted soils, compared to 851.5 mg/kg in the control soil. Total bacterial count of the rhizospheric soils collected from Ikpoba-Okha sampling site was 5.40 x 106 cfu/g; 5.30 x 106 cfu/g in Ovia NE, and 4.90 x 106 cfu/g in Egor, compared to 0.39 x 106 cfu/g in the control. Comparatively, bacterial counts outnumbered fungal counts. Percentage hydrocarbon degrading fungi was 133.3% in samples collected from Oredo, compared to 31.82 in the control. The most prevalent fungal species was Aspergillus niger , whereas Micrococcus varians was the most prevalent bacterial species.

Faecalibacterium prausnitzii prevents physiological damages in a chronic low-grade inflammation murine model.

BackgroundThe human gut houses one of the most complex and abundant ecosystems composed of up to 1013-1014 microorganisms. The importance of this intestinal microbiota is highlighted when a disruption of the intestinal ecosystem equilibrium appears (a phenomenon called dysbiosis) leading to an illness status, such as inflammatory bowel diseases (IBD). Indeed, the reduction of the commensal bacterium Faecalibacterium prausnitzii (one of the most prevalent intestinal bacterial species in healthy adults) has been correlated with several diseases, including IBD, and most importantly, it has been shown that this bacterium has anti-inflammatory and protective effects in pre-clinical models of colitis. Some dysbiosis disorders are characterized by functional and physiological alterations. Here, we report the beneficial effects of F. prausnitzii in the physiological changes induced by a chronic low-grade inflammation in a murine model. Chronic low-grade inflammation and gut dysfunction were induced in mice by two episodes of dinitro-benzene sulfonic acid (DNBS) instillations. Markers of inflammation, gut permeability, colonic serotonin and cytokine levels were studied. The effects of F. prausnitzii strain A2-165 and its culture supernatant (SN) were then investigated.ResultsNo significant differences were observed in classical inflammation markers confirming that inflammation was subclinical. However, gut permeability, colonic serotonin levels and the colonic levels of the cytokines IL-6, INF-γ, IL-4 and IL-22 were higher in DNBS-treated than in untreated mice. Importantly, mice treated with either F. prausnitzii or its SN exhibited significant decreases in intestinal permeability, tissue cytokines and serotonin levels.ConclusionsOur results show that F. prausnitzii and its SN had beneficial effects on intestinal epithelial barrier impairment in a chronic low-grade inflammation model. These observations confirm the potential of this bacterium as a novel probiotic treatment in the management of gut dysfunction and low-grade inflammation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-015-0400-1) contains supplementary material, which is available to authorized users.

Proinflammatory Activity of Primarily Infected Endodontic Content against Macrophages after Different Phases of the Root Canal Therapy

IntroductionThis study investigated the presence of target bacterial species and the levels of endotoxins in teeth with apical periodontitis. Levels of inflammatory mediators (interleukin [IL]-1β and tumor necrosis factor [TNF]-α) were determined after macrophage stimulation with endodontic content after different phases of endodontic therapy using different irrigants. MethodsThirty primarily infected root canals were randomly assigned into 3 groups according to the irrigant used for root canal preparation (n = 10 per group): GI: 2.5% sodium hypochlorite, GII: 2% chlorhexidine gel, and GIII (control group): saline solution. Root canal samples were taken by using paper points before (s1) and after root canal instrumentation (s2), subsequently to 17% EDTA (s3), after 30 days of intracanal medication (Ca[OH]2 + saline solution) (s4), and before root canal obturation (s5). Polymerase chain reaction (16S recombinant DNA) and limulus amebocyte lysate assay were used for bacterial and endotoxin detection, respectively. Macrophages were stimulated with the root canal contents for IL-1β/TNF-α measurement using enzyme-linked immunosorbent assay. ResultsPorphyromonas gingivalis (17/30), Porphyromonas endodontalis (15/30), and Prevotella nigrescens (11/30) were the most prevalent bacterial species. At s1, endotoxins were detected in 100% of the root canals (median = 32.43 EU/mL). In parallel, substantial amounts of IL-1β and TNF-α were produced by endodontic content-stimulated macrophages. At s2, a significant reduction in endotoxin levels was observed in all groups, with GI presenting the greatest reduction (P < .05). After a root canal rinse with EDTA (s3), intracanal medication (s4), and before root canal obturation (s5), endotoxin levels reduced without differences between groups (P < .05). IL-1β and TNF-α release decreased proportionally to the levels of residual endotoxin (P < .05). ConclusionsRegardless of the use of sodium hypochlorite or CHX, the greatest endotoxin reduction occurs after chemomechanical preparation. Increasing steps of root canal therapy associated with intracanal medication enhances endotoxin reduction, leading to a progressively lower activation of proinflammatory cells such as macrophages