Presence Of Potential Pathogenic Microorganisms Research Articles

Unveiling the airborne microbial menace: Novel insights into pathogenic bacteria and fungi in bioaerosols from nursery schools to universities

Bacterial and fungal aerosol pollution is widespread in indoor school environments, and poses potential health risks to students and staff. Understanding the distribution and diversity of microbial communities within aerosols is crucial to mitigate their adverse effects. Existing knowledge regarding the composition of bacterial and fungal aerosols, particularly the presence of potential pathogenic microorganisms in fine particulate matter (PM2.5) from nursery schools to universities, is limited. To bridge this knowledge gap, in the present study, we collected PM2.5 samples from five types of schools (i.e., nursery schools, primary schools, junior schools, and high schools and universities) in China. We used advanced single-molecule real-time sequencing to analyze the species-level diversity of bacterial and fungal components in PM2.5 samples based on 16S and ITS ribosomal genes, respectively. We found significant differences in microbial diversity and community composition among the samples obtained from different educational institutions and pollution levels. In particularly, junior schools exhibited higher PM2.5 concentrations (62.2–86.6 μg/m3) than other schools (14.4–48.4 μg/m3). Moreover, microbial variations in PM2.5 samples were associated with institution type. Notably, the prevailing pathogenic microorganisms included Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Streptococcus pneumoniae, and Schizophyllum commune, all of which were identified as Class II Pathogenic Microorganisms in school settings. Four potentially novel strains of S. commune were identified in PM2.5 samples collected from the university; the four strains showed 92.4 %–94.1 % ITS sequence similarity to known Schizophyllum isolates. To the best of our knowledge, this is the first study to explore bacterial and fungal diversity within PM2.5 samples from nursery schools to universities. Overall, these findings contribute to the existing knowledge of school environmental microbiology to ensure the health and safety of students and staff and impacting public health.

The Impact of Chronic Bronchial Infection in COPD: A Proposal for Management.

Up to 50% of patients with chronic obstructive pulmonary disease (COPD) in stable state may carry potentially pathogenic microorganisms (PPMs) in their airways. The presence of PPMs has been associated with increased symptoms, increased risk and severity of exacerbations, a faster decline in lung function and impairment in quality of life. Although some clinical trials have demonstrated a reduction in exacerbations in patients chronically treated with systemic antibiotics, particularly macrolides, the selection of patients was based on the previous frequency of exacerbations and not on the presence of PPMs in their airways. Therefore, unlike in bronchiectasis, there is a lack of evidence-based recommendations for assessment and treatment of the presence of PPMs in either single or repeated isolations in COPD. In this article, we propose that chronic bronchial infection (CBI) in COPD be defined as the isolation of the same PPM in at least three sputum samples separated by more than one month; we review the impact of CBI on the natural course of COPD and suggest a course of action in patients with a single isolation of a PPM or suspected CBI. Antibiotic treatment in stable COPD should be recommended based on four main criteria: a) the presence of comorbid bronchiectasis, b) the demonstration of a single or multiple isolation of the same PPM, c) the clinical impact of CBI on the patients, and d) the type of PPM, either Pseudomonas aeruginosa or non-pseudomonal PPM. These recommendations are derived from evidence generated in patients with bronchiectasis and, until new evidence specifically obtained in COPD is available, they may help in the management of these challenging patients with COPD. Existing evidence suggests that inhaled therapy is insufficient to manage patients with moderate-to-severe COPD, frequent exacerbations, and CBI. New studies must be conducted in this particularly demanding population.

Dynamics of skin microbiota in shoulder surgery infections.

Post-surgical infections arise due to various contributing factors. Most important is the presence of potential pathogenic microorganisms in the skin complemented by the patient´s health status. Cutibacterium acnes is commonly present in the pilosebaceous glands and hair follicle funnels in human skin. After surgical intervention, these highly prevalent, slow-growing bacteria can be found in the deeper tissues and in proximity of implants. C. acnes is frequently implicated in post-surgical infections, often resulting in the need for revision surgery. This review summarizes the current understanding of microbial dynamics in shoulder surgical infections. In particular, we shed light on the contribution of C. acnes to post-surgical shoulder infections as well as their colonization and immune-modulatory potential. Despite being persistently found in post-surgical tissues, C. acnes is often underestimated as a causative organism due to its slow growth and the inefficient detection methods. We discuss the role of the skin environment constituted by microbial composition and host cellular status in influencing C. acnes recolonization potential. Future mapping of the individual skin microbiome in shoulder surgery patients using advanced molecular methods would be a useful approach for determining the risk of post-operative infections.

Potential respiratory pathogens colonisation of the denture plaque of patients with chronic obstructive pulmonary disease.

The role of bacterial infections in acute exacerbations of chronic obstructive pulmonary disease (COPD) is widely examined. Denture plaque in patients with COPD is an example of bacterial and fungal biofilm, which is a reservoir of potentially pathogenic respiratory tract microorganisms. Poor denture hygiene might cause acute exacerbations of COPD. Assessment of prevalence of respiratory tract pathogens in denture plaque in stable patients with COPD and it influence on oral ontocenoses depending upon the therapy. The study was based on the clinical assessment of oral mucosa and denture hygiene in 53 patients with COPD with mean age of 70±18years and 14 generally healthy participants with mean age of 65±14years. Microbiological and mycological tests were performed by culturing direct denture swabs. The study showcased the presence of potential pathogenic micro-organisms in denture plaque of 48 patients with COPD (90%) and nine healthy subjects (64.3%). Yeast-like fungi prevailed in denture surface swabs of 40 (75%) in patients with COPD and 8 (57%) in cases of control group. In 66% of patients, various degree of oral mucosa inflammation prevailed. Denture plaque could be a potential source of bacterial and fungal infections in patients with COPD.

Colour of sputum is a marker for bacterial colonisation in chronic obstructive pulmonary disease

BackgroundBacterial colonisation in chronic obstructive pulmonary disease (COPD) contributes to airway inflammation and modulates exacerbations. We assessed risk factors for bacterial colonisation in COPD.MethodsPatients with stable COPD consecutively recruited over 1 year gave consent to provide a sputum sample for microbiologic analysis. Bronchial colonisation by potentially pathogenic microorganisms (PPMs) was defined as the isolation of PPMs at concentrations of ≥102 colony-forming units (CFU)/mL on quantitative bacterial culture. Colonised patients were divided into high (>105 CFU/mL) or low (<105 CFU/mL) bacterial load.ResultsA total of 119 patients (92.5% men, mean age 68 years, mean forced expiratory volume in one second [FEV1] [% predicted] 46.4%) were evaluated. Bacterial colonisation was demonstrated in 58 (48.7%) patients. Patients with and without bacterial colonisation showed significant differences in smoking history, cough, dyspnoea, COPD exacerbations and hospitalisations in the previous year, and sputum colour. Thirty-six patients (62% of those colonised) had a high bacterial load. More than 80% of the sputum samples with a dark yellow or greenish colour yielded PPMs in culture. In contrast, only 5.9% of white and 44.7% of light yellow sputum samples were positive (P < 0.001). Multivariate analysis showed an increased degree of dyspnoea (odds ratio [OR] = 2.63, 95% confidence interval [CI] 1.53-5.09, P = 0.004) and a darker sputum colour (OR = 4.11, 95% CI 2.30-7.29, P < 0.001) as factors associated with the presence of PPMs in sputum.ConclusionsAlmost half of our population of ambulatory moderate to very severe COPD patients were colonised with PPMs. Patients colonised present more severe dyspnoea, and a darker colour of sputum allows identification of individuals more likely to be colonised.

Real-Time PCR Detection of Pathogenic Microorganisms in Roof-Harvested Rainwater in Southeast Queensland, Australia

In this study, the microbiological quality of roof-harvested rainwater was assessed by monitoring the concentrations of Escherichia coli, enterococci, Clostridium perfringens, and Bacteroides spp. in rainwater obtained from tanks in Southeast Queensland, Australia. Samples were also tested using real-time PCR (with SYBR Green I dye) for the presence of potential pathogenic microorganisms. Of the 27 rainwater samples tested, 17 (63%), 21 (78%), 13 (48%), and 24 (89%) were positive for E. coli, enterococci, C. perfringens, and Bacteroides spp., respectively. Of the 27 samples, 11 (41%), 7 (26%), 4 (15%), 3 (11%), and 1 (4%) were PCR positive for the Campylobacter coli ceuE gene, the Legionella pneumophila mip gene, the Aeromonas hydrophila lip gene, the Salmonella invA gene, and the Campylobacter jejuni mapA gene. Of the 21 samples tested, 4 (19%) were positive for the Giardia lamblia beta-giardin gene. The binary logistic regression model indicated a positive correlation (P < 0.02) between the presence/absence of enterococci and A. hydrophila. In contrast, the presence/absence of the remaining potential pathogens did not correlate with traditional fecal indicators. The poor correlation between fecal indicators and potential pathogens suggested that fecal indicators may not be adequate to assess the microbiological quality of rainwater and consequent health risk.

Isolation and characterization of Shiga toxin-producing Escherichia coli O157:H7 and non-O157 from beef carcasses at a slaughter plant in Mexico

The contamination of beef carcasses with Shiga toxin-producing O157:H7 and non-O157 Escherichia coli (STEC) obtained from a slaughter plant in Guadalajara, Mexico was investigated. A total of 258 beef carcasses were sampled during a 12-month period. All samples were assayed for STEC by selective enrichment in modified tryptone soy broth supplemented with cefixime, cefsulodin and vancomycin, followed by plating on Sorbitol MacConkey Agar supplemented with cefixime and tellurite (CT–SMAC). Simultaneously, all samples were assayed by immunomagnetic separation (IMS) and plated on CT–SMAC and CHROMagar®. The presence of the stx1, stx2, eaeA and hly 933 genes, recognized as major virulence factors of STEC, was tested for O157:H7 and non-O157 E. coli isolates by multiplex polymerase chain reaction (PCR). STEC was detected in two (0.8%) samples. One of these STEC isolates corresponded to the serotype O157:H7 showing stx2, eaeA and hyl 933 genes. The other isolate corresponded to non-O157 STEC and only had the stx1 gene. Thirteen carcasses (5%) were positive for nonmotile E. coli O157 and 7 (2.7%) were positive for E. coli O157:H7. The presence of O157:H7 and non-O157 STEC on beef carcasses in this slaughter plant in Guadalajara, Mexico, emphasizes the importance of implementing the Hazard Analysis and Critical Control Point (HACCP) system, as well as the need for implementing, evaluating, and validating antimicrobial interventions to reduce the presence of potential pathogenic microorganisms.

Airway inflammation and bronchial microbial patterns in patients with stable chronic obstructive pulmonary disease.

The effect of bacterial colonization of the bronchi on the progress of airflow limitation is not well known. Therefore, the pattern of airway inflammation in smokers and patients with stable chronic obstructive pulmonary disease (COPD) and its relation to bronchial microbial colonization was assessed. Eight nonsmoking and 18 smoking controls as well as 52 patients with COPD (28 mild, 11 moderate and 13 severe) were studied. All subjects were investigated by means of flexible bronchoscopy including protected specimen brush and bronchoalveolar lavage (BAL) sampling. Differential cell counts, cytokine (interleukin (IL)-1beta, IL-6, IL-8, IL-10 and tumour necrosis factor-alpha(TNF-alpha) concentrations and microbial patterns were determined in BAL fluid. Forced expiratory volume in one second (FEV1) % of the predicted value was inversely correlated with pack-yrs of cigarette smoking (r=-0.47, p<0.0001), the percentage of neutrophil (p=-0.56, p<0.0001) and IL-6 (p=-0.37, p=0.01) and IL-8 concentration (p=-0.43, p=0.004) in BAL fluid. Accordingly, pk-yrs of cigarette smoking (p=0.39, p=0.01) and IL-8 (p=0.69, p<0.0001) and TNFalpha (p=0.4, p<0.005) were positively correlated with the percentage of neutrophils in BAL fluid. Smoking controls and COPD patients were mainly colonized in the bronchial tree (33%) by community endogenous potentially pathogenic micro-organisms (PPMs). Colonization rates and patterns of PPMs were not affected by severity of airflow obstruction. The presence of PPMs was significantly associated with higher percentages of neutrophils (33.2+/-10.4% versus 10.1+/-3.5%, p=0.02) and TNF-alpha concentration (29.9+/-10.8 versus 6.3+/-2.1 pg x mL(-1), p=0.01) in BAL fluid. In conclusion, bronchial neutrophilia is a key inflammatory pattern in chronic obstructive pulmonary disease patients. Bronchial colonization with potentially pathogenic micro-organisms may represent an independent stimulus for additional airway inflammation.