Prevalence and antibiotic susceptibility patterns of uropathogens in men with prostate cancer and benign prostate hyperplasia from Southwestern Nigeria.

BACKGROUND: Epidemiological investigations have revealed an important association between infection, inflammation and prostate cancer. Certain bacterial species, such as Klebsiella spp, Escherichia coli, Pseudomonas spp, Proteus mirabilis, Chlamydia trachomatis have been linked to prostate cancer. This study aimed to examine the microbiota; specifically bacterial species that have been linked to prostate infections in the urine of individuals diagnosed with prostate cancer. RESULTS: Sixty-six prostate cancer patients and forty controls provided midstream urine samples. The urine samples were grown on suitable medium, and bacterial isolates were detected by standard microbiological methods. Additionally, the antibiotic sensitivity pattern of the bacterial isolates was analysed. A total of number of 72 bacterial isolates were obtained from the urine of study participants. The results showed the presence of Escherichia coli (50.0%), Pseudomonas aeruginosa (18.1%), Klebsiella spp (15.3%), Staphylococcus aureus (8.3%), Enterobacter spp (4.2%), and Proteus mirabilis (2.8%) in the urine. The most common bacterial species isolated from prostate cancer patients was Escherichia coli, which was susceptible to levofloxacin (100%), tobramycin (91.7%), and amikacin (62.5%). CONCLUSIONS: This study's findings established the presence of bacteria previously linked to prostatitis. This report indicates a high prevalence of pro-inflammatory bacteria and uropathogens in the urinary tract of men diagnosed with prostate cancer.

Mucin adhesion of serial cystic fibrosis airways Pseudomonas aeruginosa isolates.

The chronic airway infections with Pseudomonas aeruginosa are the major co-morbidity in people with cystic fibrosis (CF). Within CF lungs, P. aeruginosa persists in the conducting airways together with human mucins as the most abundant structural component of its microenvironment. We investigated the adhesion of 41 serial CF airway P. aeruginosa isolates to airway mucin preparations from CF sputa. Mucins and bacteria were retrieved from five modulator-naïve patients with advanced CF lung disease. The P. aeruginosa isolates from CF airways and non-CF reference strains showed a strain-specific signature in their adhesion to ovine, porcine and bovine submaxillary mucins and CF airway mucins ranging from no or low to moderate and strong binding. Serial CF clonal isolates and colony morphotypes from the same sputum sample were as heterogeneous in their affinity to mucin as representatives of other clones thus making 'mucin binding' one of the most variable intraclonal phenotypic traits of P. aeruginosa known to date. Most P. aeruginosa CF airway isolates did not adhere more strongly to CF airway mucins than to plastic surfaces. The strong binders, however, exhibited a strain-specific affinity gradient to O-glycans, CF airway and mammalian submaxillary mucins.

Rapid bone destruction caused by multidrug-resistant Pseudomonas aeruginosa septic arthritis: A case report.

RATIONALE: Infections due to multidrug-resistant (MDR) Pseudomonas aeruginosa are strongly associated with poor outcomes, including prolonged hospitalization and an increased risk of mortality. Antimicrobial options for the treatment of severe infections due to MDR P aeruginosa are quite limited, and treatment remains challenging. PATIENT CONCERNS: A 65-year-old woman presented to our orthopedic clinic with a 3-month history of progressive pain and stiffness in her left knee. Her primary care provider administered a hyaluronic acid injection, which unfortunately resulted in worsening symptoms. Subsequent treatment included a 1-month course of intravenous gentamicin and ceftriaxone, which failed to alleviate her symptoms. DIAGNOSIS: MDR P aeruginosa septic arthritis of the knee. The culture isolate was tested for susceptibility to multiple antibiotics. Magnetic resonance imaging evaluations were conducted, showing notable erosive and osteolytic changes around the joint surfaces that had progressed significantly. INTERVENTIONS: The patient underwent arthroscopic irrigation and synovectomy. The treatment regimen included a combination of intravenous colistin and piperacillin/tazobactam administered over a 6-week period. Total knee arthroplasty was performed 6 months later without additional antibiotic treatment. OUTCOMES: Patient's knee condition remained continuously stable without abnormal findings of inflammation. The patient's knee range of motion increased 0 to 125 degrees, her pain almost disappeared, and she was able to maintain activities of daily life. LESSONS: This case underscores the challenges of managing infections with MDR organisms in complex clinical scenarios, emphasizing the need for timely intervention and appropriate antibiotic therapy.

Innovative Treatment of Carbapenem-Resistant Pseudomonas aeruginosa Pneumonia with Carrimycin: A Case Report.

Carbapenem-resistant Pseudomonas aeruginosa is a common multidrug-resistant bacterium encountered in clinical practice. This pathogen causes pneumonia, which is difficult to treat owing to the limited choice of antimicrobial drugs, resulting in a relatively high mortality rate. Carrimycin is a new macrolide antibiotic with broad-spectrum antibacterial and potential immunomodulatory effects. Herein, we report a case of severe pneumonia caused by carbapenem-resistant Pseudomonas aeruginosa that presented with septic shock and Acute Respiratory Distress Syndrome (ARDS). Initially, we used piperacillin-tazobactam and ceftazidime-avibactam but without satisfactory results. Finally, we administered carrimycin in combination with piperacillin-tazobactam; the patient's condition improved, and he was successfully weaned off the ventilator. Therefore, the combined use of carrimycin should be considered for patients infected with carbapenem-resistant Pseudomonas aeruginosa who do not respond to conventional anti-infection treatments.

Detection of Pseudomonas aeruginosa pus wound isolate using a polymerase chain reaction targeting 16S rRNA and gyrB genes: A case from Indonesia.

Infectious wounds on the skin surface are easily colonized by bacteria from pyogenic group that manifest as inflammation, such as Pseudomonas aeruginosa. P. aeruginosa is a Gram-negative bacterium and an opportunistic pathogen known for causing invasive state in critically ill and immunocompromised patients. The aim of this study was to detect the 16S rRNA and gyrB genes in P. aeruginosa using polymerase chain reaction (PCR) method. The sample in this study was pus isolate from a 5-year-old boy with leg wounds. The bacteria were isolated on brain heart infusion broth (BHIB) media and identified with molecular identification. Sequencing and BLAST analysis were carried out to determine the similarity of gene identity by comparing sample sequence with other isolate sequences on the Gene Bank. The results of molecular identification showed amplification DNA band of around 934 base pairs (bp) for 16S rRNA and 225 bp for gyrB gene. The BLAST program demonstrated that the sample had 99.89% similarity with P. aeruginosa strain XC4 (accession code ON795960.1) for the 16S rRNA gene. Meanwhile, the gyrB gene exhibited 99.10% similarity with the P. aeruginosa strain PSA-1.2 (accession code KP172300.1).

Exploring antibiotic-induced persister formation and bacterial persistence genes in clinical isolates from Burkina Faso.

BACKGROUND: In addition to antibiotic resistance, persistence is another cause of treatment failure in bacterial infections, representing a significant public health concern. Due to a lack of adequate data on clinical isolates, this study was initiated to investigate persistence in clinical isolates in Burkina Faso. METHODS: Eighty (80) clinical isolates, including 32 Pseudomonas aeruginosa, 41 Staphylococcus aureus, and 7 Salmonella sp. obtained from clinical laboratories in Burkina Faso, were analyzed to assess their susceptibility to ciprofloxacin and gentamicin, as well as to determine the presence of persistence genes. The effects of ciprofloxacin and gentamicin on persister formation were evaluated by conducting colony counts at 1, 3, 5, 7, and 20 h after exposing the bacteria to high concentrations of these antibiotics. RESULTS: Results showed high sensitivity to both antibiotics (72.5% for ciprofloxacin and 82.5% for gentamicin). Persister formation occurred in Staphylococcus aureus with gentamicin and in Salmonella sp. with ciprofloxacin, while Pseudomonas aeruginosa did not form persisters. The mazF gene was found in 28.13% of P. aeruginosa and 2.44% of S. aureus isolates, and the hipA gene in 28.57% of Salmonella sp. None of the relE1 or relE2 genes were detected. CONCLUSIONS: The study revealed high sensitivity in clinical bacterial isolates to ciprofloxacin and gentamicin. Staphylococcus aureus and Salmonella sp. showed persister formation under antibiotic stress, with low frequencies of the studied persistence genes. These findings enhance understanding of clinical bacterial behavior and inform strategies against antibiotic-resistant infections.

Antimicrobial resistance profile of Pseudomonas aeruginosa clinical isolates from healthcare-associated infections in Ethiopia: A systematic review and meta-analysis.

BACKGROUND: Antimicrobial-resistant (AMR) bacterial infection is a significant global threat to the healthcare systems. Pseudomonas aeruginosa, the leading infectious agent in the healthcare setting is now one of the major threats due to AMR. A comprehensive understanding of the magnitude of AMR, particularly highly public health important pathogens such as P. aeruginosa, is necessary for the management of infections based on local information. OBJECTIVE: This systematic review and meta-analysis aimed to determine the country-wide AMR of P. aeruginosa. METHODS: Systematic searches were performed to retrieve articles from PubMed, Scopus, Web of Science, ScienceDirect electronic databases, Google Scholar search engine, and repository registrars from 2015 to 31st December 2023. Twenty-three studies that provided important data on AMR in P. aeruginosa were systematically reviewed and analyzed to determine the country-wide magnitude of P. aeruginosa AMR profile from healthcare-associated infections. AMR of P. aeruginosa to 10 different antibiotics were extracted separately into Microsoft Excel and analyzed using STATA 17.0. Cohen's kappa was computed to determine the agreement between reviewers, the Inverse of variance (I2) was used to evaluate heterogeneity across studies, and Egger's test to identify publication bias. A random effect model was used to determine the pooled resistance to each antibiotic. Subgroup analysis was performed by infection type and year of publication. RESULTS: This systematic review and meta-analysis revealed that the pooled prevalence of P. aeruginosa in clinical specimens associated with HAI was 4.38%(95%CI: 3.00-5.76). The pooled prevalence of AMR in P. aeruginosa for different antibiotics varies, ranging from 20.9% (95%CI: 6.2-35.8) for amikacin to 98.72% (95%CI: 96.39-101.4) for ceftriaxone. The pooled resistance was higher for ceftriaxone (98.72%), Trimethoprim-sulfamethoxazole (75.41), and amoxicillin-clavulanic acid (91.2). In contrast relatively lower AMR were observed for amikacin (20.9%) and meropenem (28.64%). The pooled multi-drug resistance (MDR) in P. aeruginosa was 80.5% (95%CI: 66.25-93.84). Upon subgroup analysis by infection types and year of publication, P. aeruginosa isolated from healthcare-associated infections exhibited higher resistance to ceftazidime (94.72%) compared to isolates from mixed types of healthcare-associated infections (70.84%) and surgical site infections (57.84%). Antimicrobial resistance in gentamicin was higher during the periods of 2018-2020 (73.96%), while comparatively lower during 2021-2023 (42.69%) and 2015-2017 (29.82%). CONCLUSIONS: Significantly high AMR and MDR were observed from this systematic review and meta-analysis. AMR obtained from this systematic review and meta-analysis urges the need for improved infection control, antimicrobial stewardship practices, and strengthened surveillance systems to control the spread of AMR and ensure effective treatment of P. aeruginosa infections. PROTOCOL REGISTRATION: This systematic review and meta-analysis was registered on PROSPERO (Registration ID: CRD42024518145).

Respiratory Pathogens at Exacerbation in Chronic Bronchitis With Airway Bacterial Colonisation: A Cohort Study.

BACKGROUND AND OBJECTIVE: COPD and bronchiectasis are common causes of morbidity, particularly around exacerbation. Colonisation with respiratory pathogens can increase the frequency and severity of exacerbations. However, bacterial and viral presence at exacerbation in people with airway colonisation has not been well studied. METHODS: A 6-month cohort study of participants (n = 30) with chronic bronchitis due to bronchiectasis (n = 26) and/or COPD (n = 13) and colonisation with Pseudomonas aeruginosa or Haemophilus influenzae was proven on two sputum cultures at exacerbation in the previous 12 months. Participants were provided self-management education and collected sputum samples daily. Sputum samples at baseline (at least 14 days before or after an exacerbation) and at each exacerbation were examined for a panel of 34 respiratory pathogens using commercially available RT-PCR kits and compared to results obtained using culture methods for the detection of bacteria. RESULTS: Participants provided 29 baseline samples and 71 samples at exacerbation. In 17/29 baseline samples, RT-PCR analysis confirmed the organism demonstrated by culture, while 12 samples showed a discrepancy from culture results. Most exacerbations (57.7%) were not associated with acquiring new bacteria or viruses, while 19.8% showed new bacteria, 15.7% new viruses and 7% both new viruses and bacteria. CONCLUSION: Over half of exacerbations were not associated with new organisms in this cohort of participants with chronic bronchitis and colonisation. However, 26.8% demonstrated a new bacterial species in sputum, which is relevant for antibiotic therapy. Baseline RT-PCR and culture results were discordant in one-third of participants.

[Distribution and Drug Resistance Characteristics of Pathogenic Bacteria in the Elderly Population in China in 2021]. / 2021å¹´ä¸­å›½è€å¹´äººç¾¤æ„ŸæŸ“ç— åŽŸèŒåˆ†å¸ƒå’Œè€è¯æ€§ç‰¹å¾.

Objective: To study the distribution and drug resistance characteristics of pathogenic bacteria in the elderly population of China by collecting and analyzing the standardized case data on the pathogens of infections in elderly patients, and to facilitate the establishment of a standardized layered surveillance system for pathogenic bacteria in China. Methods: We collected the case data of elderly patients (≥65 years old) from 62 sentinel hospitals across the country in 2021. Then, we statistically analyzed the data by patient age, their geographical region, the distribution of pathogenic bacteria, and the drug resistance characteristics of main pathogens. Results: A total of 3468 cases from across the country were included in the study. The top three sources of patients were the intensive care unit (13.2%), the department of respiratory medicine (11.2%), and the department of general surgery (8.4%). The top three types of specimens were urine (25.5%), sputum (20.6%), and blood (18.7%). A total of 3468 strains of pathogens were isolated, among which, 78.9% were gram-negative bacteria and 21.1% were gram-positive bacteria. The top five types of bacteria were Escherichia coli (20.9%), Klebsiella pneumoniae (18.3%), Pseudomonas aeruginosa (11.2%), Staphylococcus aureus (9.0%), and Acinetobacter baumannii (7.0%). The isolation rates of common important drug-resistant bacteria were 38.0% for methicillin-resistant Staphylococcus aureus (MRSA), 68.7% for carbapenem-resistant Acinetobacter baumannii (CRAB), and 38.2% for carbapenem-resistant Pseudomonas aeruginosa (CRPA), 20.1% for carbapenem-resistant Klebsiella pneumoniae (CRKP), 5.2% for carbapenem-resistant Escherichia coli (CRECO), and 2.1% for vancomycin-resistant Enterococcus (VRE). There were differences in the isolation rates of CRAB and CRKP in clinical care in the elderly population in seven geographical regions of China (P<0.05). Klebsiella pneumoniae is the most important pathogen in the elderly population ≥85 years old, and the isolation rates of CRKP showed significant differences in different age groups (P<0.05). Conclusion: There are significant differences in the drug resistance of pathogenic bacteria in the elderly populations of different regions and age groups in China. Therefore, monitoring the distribution and drug resistance of pathogenic bacteria in the elderly population and formulating targeted treatment plans according to the characteristics of the specific regions and age groups are of great significance to the improvement in the treatment outcomes and prognosis of the elderly population.

Simple and sensitive detection of Pseudomonas aeruginosa in neonatal infection based on a both-end blocked peroxidase-mimicking DNAzyme.

Developing a simple and highly sensitive approach for Pseudomonas aeruginosa (P. aeruginosa) detection is crucial, as it is closely associated with various disorders, such as newborn infections. Nevertheless, few of techniques have the capability to accurately identify P. aeruginosa with a high level of sensitivity and significantly improved stability. The employment of the both-end blocked peroxidase-mimicking DNAzyme significantly diminished the interferences from background signals, so conferring the approach with a high degree of selectivity and reproducibility. The proposed method is demonstrated with exceptional discernment capacity in differentiating interfering microorganisms. The simplicity, elevated sensitivity and high discerning capability make the method a highly promising alternative instrument for pathogenic bacteria detection.

This research presents a novel method for detecting P. aeruginosa using a combination of a simple molecular beacon (MB), duplex-specific nuclease (DSN), and both-end blocked peroxidase-mimicking DNAzyme. The MB probe utilized in this method can be shielded from DSN hydrolysis without requiring any additional modifications by regulating the number of stem bases to five. This assay is simple yet precise in its ability to quantitatively detect P. aeruginosa with a high level of sensitivity and specificity. In addition, the beacon enabled the identification of P. aeruginosa without the need for labeling, exhibiting a higher sensitivity over the conventional hairpin fluorescence beacon based methods.

An in-depth study on survival mechanism of bacterial isolates in disinfectants within the hospital environment.

Introduction: The emergence of disinfectant resistance has become a severe threat due to reduced effectiveness. This study was undertaken to determine how bacteria adapt to survive exposure to disinfectants in the busiest section of a tertiary care hospital in Varanasi, India. Methods: Four isolates (two Klebsiella pneumoniae, Kp1 and Kp2; two Pseudomonas aeruginosa, Pa1 and Pa2) were obtained from chlorhexidine (CHX)-based handwash during microbiological surveillance of "in-use disinfectants" in hospital. Six disinfectants [4% CHX, 2% glutaraldehyde, 7.5% hydrogen peroxide, 1% sodium hypochlorite and 0.1% benzalkonium chloride (BAC), and 70% ethyl alcohol] were tested against these four isolates to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Antibiotic profile, change in MIC on exposure to disinfectants and biofilm formation in the presence and absence of disinfectants was studied. Whole genome sequencing (WGS) was done to identify the resistance mechanisms. Result: The isolates showed the highest MBC/MIC ratio (4) against glutaraldehyde. Exposure to supra-inhibitory concentration of BAC for 21 days resulted in doubling of MIC/MBC. The majority (75%) of the isolates were multidrug resistant. All the isolates were strong biofilm producers. The reduction rate of biofilm formation decreased with an increase in the concentration of disinfectants (p = 0.05 for BAC). WGS revealed multiple AMR genes including bla DIM-1, disinfectant-resistant gene and efflux pump genes. Conclusion: The study emphasized the various adaptation strategies of these isolates for survival in disinfectant environment, thus posing a huge challenge for their control in the hospital environment.

Gram-negative bacterial colonization in the gut: Isolation, characterization, and identification of resistance mechanisms.

BACKGROUND: The gut microbiome is made up of a diverse range of bacteria, especially gram-negative bacteria, and is crucial for human health and illness. There is a great deal of interest in the dynamic interactions between gram-negative bacteria and their host environment, especially considering antibiotic resistance. This work aims to isolate gram-negative bacteria that exist in the gut, identify their species, and use resistance-associated gene analysis to define their resistance mechanisms. METHODS: Samples were collected from all patients who had a stool culture at a tertiary care center in Lebanon. Each type of bacteria that was identified from the stool samples was subjected to critical evaluations, and all discovered strains underwent antimicrobial susceptibility testing. Polymerase chain reaction was used to profile the genes for Carbapenem-resistant Enterobacteriaceae (CRE), Extended-spectrum beta-lactamase (ESBL), and that of Pseudomonas aeruginosa strains. RESULTS: Escherichia coli, Klebsiella species, and Pseudomonas aeruginosa turned out to be the predominant microbiota members. Escherichia coli strains had a high frequency of extended-spectrum beta-lactamase genes, with the most discovered gene being bla CTX-M. Additionally, a considerable percentage of isolates had carbapenemase-resistant Enterobacteriaceae genes, suggesting the rise of multidrug-resistant strains. Multidrug resistance genes, such as bla mexR, bla mexB, and bla mexA, were found in strains of Pseudomonas aeruginosa, highlighting the possible difficulties in treating infections brought on by these bacteria. CONCLUSION: The findings highlight the critical importance of effective surveillance and response measures to maintain the effectiveness of antibiotics considering the introduction of multidrug resistance genes in Pseudomonas aeruginosa and ESBL and CRE genes in Escherichia coli.

Fabrication of Aluminum Foil Integrated Pegylated Gold Nanoparticle Surface-Enhanced Raman Scattering Substrate for the Detection and Classification of Uropathogenic Bacteria.

Rapid detection and classification of pathogenic microbes for food hygiene, healthcare, environmental contamination, and chemical and biological exposures remain a major challenge due to nonavailability of fast and accurate detection methods. The delay in clinical diagnosis of the most frequent bacterial infections, particularly urinary tract infections (UTIs), which affect about half of the population at least once in their lifetime, can be fatal if not detected and treated appropriately. In this work, we have fabricated aluminum (Al) foil integrated pegylated gold nanoparticles (AuNPs) as a potential surface-enhanced Raman scattering (SERS) substrate, which is used for the detection and classification of uropathogens, namely, E. coli, S. aureus, and P. aeruginosa directly from the culture without any pretreatment. The substrate is first drop cast with bacterial pellets and then pegylated AuNPs, and the interaction of two on Al foil base gives identifiable characteristic Raman peaks with good reproducibility. With the use of chemometric methods such as principal component analysis (PCA), the Al foil-based SERS substrate offers a quick, effective detection and classification of three strains of UTI bacteria with the least bacterial concentration (105 cells mL-1) necessary for clinical diagnosis. In addition, this substrate was able to detect E. coli positive clinical samples by giving SERS fingerprint information directly from centrifuged urine samples within minutes. The stability of pegylated AuNPs provides for its application at the point of care with rapid and easy detection of uropathogens as well as the possibility of advancement in healthcare applications.

Exploring Ventilator-Associated Pneumonia: Microbial Clues and Biomarker Insights from a Retrospective Study.

Background and Objectives: Ventilator-associated pneumonia (VAP) is a common complication in critically ill patients receiving mechanical ventilation. The incidence rates of VAP vary, and it poses significant challenges due to microbial resistance and the potential for adverse outcomes. This study aims to explore the microbial profile of VAP and evaluate the utility of biomarkers and illness severity scores in predicting survival. Materials and Methods: A retrospective cohort study was conducted involving 130 patients diagnosed with VAP. Microbial analysis of bronchoalveolar lavage (BAL) fluid, as well as measurements of C-reactive protein (CRP) and procalcitonin (PCT) levels, were performed. Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were calculated to assess illness severity. Statistical analyses were conducted to determine correlations and associations. Results: The study revealed that Klebsiella pneumoniae (K. pneumoniae) (50.7%) and Pseudomonas aeruginosa (P. aeruginosa) (27.69%) were the most identified microorganisms in VAP cases. SOFA (p-value < 0.0001) and APACHE II (p-value < 0.0001) scores were effective in assessing the severity of illness and predicting mortality in VAP patients. Additionally, our investigation highlighted the prognostic potential of CRP levels (odds ratio [OR]: 0.980, 95% confidence interval [CI] 0.968 to 0.992, p = 0.001). Elevated levels of CRP were associated with reduced survival probabilities in VAP patients. Conclusion: This study highlights the microbial profile of VAP and the importance of biomarkers and illness severity scores in predicting survival. Conclusions: The findings emphasize the need for appropriate management strategies to combat microbial resistance and improve outcomes in VAP patients.

CRISPR/Cas12a-drived electrochemiluminescence and fluorescence dual-mode magnetic biosensor for sensitive detection of Pseudomonas aeruginosa based on iridium(III) complex as luminophore.

The opportunistic human pathogen Pseudomonas aeruginosa (P. aeruginosa) poses a significant threat to human health, causing sepsis, inflammation, and pneumonia, so it is crucial to devise an expeditious detection platform for the P. aeruginosa. In this work, bis (2- (3, 5- dimethylphenyl) quinoline- C2, N') (acetylacetonato) iridium (III) Ir (dmpq)2 (acac) with excellent electrochemiluminescence (ECL) and fluorescence (FL) and magnetic nanoparticles were encapsulated in silica spheres. The luminescent units exhibited equal ECL and FL properties compared with single iridium complexes, and enabled rapid separation, which was of vital significance for the establishment of biosensors with effective detection. In addition, the luminescent units were further reacted with the DNA with quenching units to obtain the signal units, and the ECL/FL dual-mode biosensor was employed with the CRISPR/Cas12a system to further improve its specific recognition ability. The ECL detection linear range of as-proposed biosensor in this work was 100 fM-10 nM with the detection limit of 73 fM (S/N = 3), and FL detection linear range was 1 pM-10 nM with the detection limit of 0.126 pM (S/N = 3). Importantly, the proposed dual-mode biosensor exhibited excellent repeatability and stability in the detection of P. aeruginosa in real samples, underscoring its potential as an alternative strategy for infection prevention and safeguarding public health and safety in the future.

Malignant Otitis Externa: A persistent challenge.

INTRODUCTION: Although rare, Malignant otitis externa is responsible for a high morbidity and could sometimes be fatal. The management of this condition is still challenging. AIM: To analyse the clinical, microbiological and radiological profile of malignant otitis externa, and the management of this condition. METHODS: A descriptive, cross-sectional study was conducted at ENT Department of Kairouan's hospital including 38 patients hospitalised and treated for malignant otitis externa from January 2013 to August 2021. RESULTS: The mean age of patients was 67.7 ± 12.9 years (35-98). All patients presented with continuous otalgia that resists to usual analgesics. Otorrhea was noticed in 76.3% of cases, facial palsy in 2 cases (5.3%) and dysphonia in one case (2.6%). Pseudomonas Aeruginosa was the main responsible pathogen (42%). Concomitant bacterial and fungal infection was noticed in 6.4% of the cases. First-line intravenous antibiotherapy used was mainly based on an association of Cephalosporins and Fluoroquinolones. Complete remission was noticed in 30 patients (79%). However, 8 cases of recurrences (21%) and 2 cases of deaths (5.2%) were noticed in our series. The mean follow-up was 4.6±6.3 (1-26 months). CONCLUSIONS: Pseudomonas Aeruginosa remains the main responsible pathogen for malignant otitis externa. Nevertheless, fungal infections are rising because of the overuse of antibiotics. Antibiotherapy should be adapted to culture results and resistance profile of pathogens in hospital. Practionners should be aware of the possibility of concomitant fungal infection, especially in the case of unfavorable evolution.

Antibacterial and antibiofilm effect of Zinc Oxide nanoparticles on P. aeruginosa variants isolated from young patients with cystic fibrosis.

BACKGROUND: P. aeruginosa, a biofilm-forming bacteria, is the main cause of pulmonary infection in CF patients. We applied ZnO-np as a therapeutic agent for eradicating multi-drug resistance and biofilm-forming P. aeruginosa isolated from young CF patients. METHODS: A total of 73 throat and sputum samples taken from young CF patients were inquired. ZnO-np was synthesized and characterized in terms of size, shape, and structure for anti-bacterial activity. The antibiotic susceptibility of isolates before and after the addition of 16 µg/ml of ZnO was evaluated using disc diffusion and microtiter methods, respectively. The gene expression level of QS genes was assessed after treatment with 16 µg/ml ZnO-np. RESULTS: The optimum concentration of ZnO-np with a higher inhibitory zone was 16 µg/ml (MIC) and 32 µg/ml (MBC). All isolates were resistant to applied antibiotics, and about 45 % of isolates were strong biofilm-forming bacteria. After treatment with 16 µg/ml ZnO-np, all strains became susceptible to the applied antibiotic except for amikacin, which confers an intermediate pattern. About 63 % and 20 % of isolates were, respectively, non-biofilm and weak biofilm-forming bacteria following the addition of ZnO-np. Relative gene expression of gacA, lasR, and rhlR genes were downregulated significantly (P < 0.001). Although the retS did not have a significant reduction (P = 0.2) CONCLUSION: ZnO-np at a concentration of 16 µg/ml could significantly reduce the P. aeruginosa infection by altering the antibiotic susceptibility pattern and inhibiting biofilm formation. Due to their photocatalytic properties and their ability to penetrate the extracellular polysaccharide layer, ZnO nanoparticles can produce ROS, which increases their susceptibility to antibiotics. Nasal delivery of ZnO-np in the form of aerosol can be considered a potential strategy to decrease the mortality rate in CF patients at an early age.

Metabolic specialization drives reduced pathogenicity in Pseudomonas aeruginosa isolates from cystic fibrosis patients.

Metabolism provides the foundation for all cellular functions. During persistent infections, in adapted pathogenic bacteria metabolism functions radically differently compared with more naïve strains. Whether this is simply a necessary accommodation to the persistence phenotype or if metabolism plays a direct role in achieving persistence in the host is still unclear. Here, we characterize a convergent shift in metabolic function(s) linked with the persistence phenotype during Pseudomonas aeruginosa colonization in the airways of people with cystic fibrosis. We show that clinically relevant mutations in the key metabolic enzyme, pyruvate dehydrogenase, lead to a host-specialized metabolism together with a lower virulence and immune response recruitment. These changes in infection phenotype are mediated by impaired type III secretion system activity and by secretion of the antioxidant metabolite, pyruvate, respectively. Our results show how metabolic adaptations directly impinge on persistence and pathogenicity in this organism.

Metrological evaluation of DNA extraction method effects on the bacterial microbiome and resistome in sputum.

Targeted high-throughput sequencing (HTS) has revolutionized the way we look at bacterial communities. It can be used for the species-specific detection of bacteria as well as for the determination of the microbiome and resistome and can be applied to samples from almost any environment. However, the results of targeted HTS can be influenced by many factors, which poses a major challenge for its use in clinical diagnostics. In this study, we investigated the impact of the DNA extraction method on the determination of the bacterial microbiome and resistome by targeted HTS using principles from metrology and diagnostics such as repeatability and analytical sensitivity. Sputum samples spiked with Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa at three different concentrations (103-106 cells/mL) were used. DNA was extracted from each sample on 2 separate days in three replicates each using three different extraction methods based on cetrimonium bromide, magnetic beads, and silica membranes. All three spiked bacteria were detected in sputum, and the DNA extraction method had no significant effect on detection. However, the DNA extraction method had significant effects on the composition of the microbiome and the resistome. The sequencing results were repeatable in the majority of cases. The silica membrane-based DNA extraction kit provided the most repeatable results and the highest diversity of the microbiome and resistome. Targeted HTS has been shown to be a reliable tool for determining the microbiome and resistome; however, the method of DNA extraction should be carefully selected to minimize its impact on the results. IMPORTANCE: High-throughput sequencing (HTS) is one of the crucial new technologies that gives us insights into previously hidden parts of microbial communities. The DNA extraction method is an important step that can have a major impact on the results, and understanding this impact is of paramount importance for their reliable interpretation. Our results are of great value for the interpretation of sputum microbiome and resistome results obtained by targeted HTS. Our findings allow for a more rational design of future microbiome studies, which would lead to higher repeatability of results and easier comparison between different laboratories. This could also facilitate the introduction of targeted HTS in clinical microbiology for reliable identification of pathogenic bacteria and testing for antimicrobial resistance (AMR). As AMR is a major threat to public health, the improved methods for determining AMR would bring great benefits to both the healthcare system and society as a whole.

ESKAPE pathogens in pediatric cardiac surgery patients: 5-year microbiological monitoring in a tertiary hospital in Kazakhstan.

Hospital acquired infections greatly affect recovery and survival in pediatric surgical patients. We evaluated prevalence and antimicrobial resistance of ESKAPE pathogens in neonates and infants subjected to cardiac surgery in a tertiary hospital in Central Kazakhstan between 2019 and 2023 (2,278 patients) using routine methods of microbiological detection. ESKAPE pathogens were found in 1,899 out of 2,957 samples (Staphylococcus aureus - 35.3%, Klebsiella pneumoniae - 27.8%, Acinetobacter baumannii - 14.5%, Pseudomonas aeruginosa - 12.4%, Enterobacter sp. - 8.8%, Enterococcus faecium - 1.2%). The total prevalence of ESKAPE increased significantly from 45.1 to 76.9% (P = 0.005) during the study period. The resistance significantly increased in methicillin-resistant S. aureus (MRSA, from 13.7 to 41.9%, P = 0.041) but decreased in carbapenem-resistant P. aeruginosa (from 64.3 to 37.7%, P = 0.037) and carbapenem-resistant A. baumannii (from 48.5 to 19.1%, P = 0.039). Gradual but non-significant changes were shown in third-generation cephalosporin resistant K. pneumoniae (from 63.6 to 45.2%) and carbapenem-resistant K. pneumoniae (from 0 to 8.3%). The relative prevalence of ESKAPE pathogens steadily increased in our pediatric cardiac surgery patients in 2019-2023. The most frequent were S. aureus, K. pneumoniae, and A. baumannii, with dramatically increasing tendencies for MRSA. Our results highlight the necessity for a well-designed infection control strategy and constant microbiological monitoring in pediatric cardiac surgery departments.