Search Results (9)

The formation of a protective biofilm by Pseudomonas aeruginosa (PA) is one of the hallmarks of their survival both in vivo and in harsh environmental conditions, thus, biofilm-eradication has relevance from therapeutic perspectives and for infection control. The aim of our study was to investigate the possible relationship between antibiotic resistance, biofilm-forming capacity and virulence factors in n = 166 PA isolates of environmental origin. Antimicrobial susceptibility testing and the phenotypic detection of resistance determinants were carried out using standard protocols. The biofilm-forming capacity of PA was tested using a standardized crystal violet microtiter plate-based method. Motility (swimming, swarming, and twitching) and siderophore production of the isolates were also assessed. Resistance rates were highest for ciprofloxacin (46.98%), levofloxacin (45.18%), ceftazidime (31.92%) and cefepime (30.12%); 19.28% of isolates met the criteria to be classified as multidrug-resistant (MDR). Efflux pump overexpression, AmpC overexpression, and modified Hodge-test positivity were noted in 28.31%, 18.07% and 3.61%, respectively. 22.89% of isolates were weak/non-biofilm producers, while 27.71% and 49.40% were moderate and strong biofilm producers, respectively. Based on MDR status of the isolates, no significant differences in biofilm-production were shown among environmental PA (non-MDR OD₅₇₀ [mean ± SD]: 0.416 ± 0.167 vs. MDR OD₅₇₀: 0.399 ± 0.192; p > 0.05). No significant association was observed between either motility types in the context of drug resistance or biofilm-forming capacity (p > 0.05). 83.13% of isolates tested were positive for siderophore production. The importance of PA as a pathogen in chronic and healthcare-associated infections has been described extensively, while there is increasing awareness of PA as an environmental agent in agriculture and aquaculture. Additional studies in this field would be an important undertaking to understand the interrelated nature of biofilm production and antimicrobial resistance, as these insights may become relevant bases for developing novel therapeutics and eradication strategies against PA. Full article

Staphylococcus species are considered important members of the normal skin microbiota, in addition to being common pathogens in human and animal infections. In addition to S. aureus, other members of the genus are now widely-recognized as pathogens, especially in immunocompromised individuals. One of the most important virulence factors of staphylococci is the formation of biofilm (slime), which enhances their survival on inanimate surfaces, in addition to providing protection against immune cells and antibiotics in vivo. There has been considerable interest in the study of the relationship between biofilm formation and the antibiotic resistant phenotype, however, the results in the available literature are inconsistent. Thus, this study aims to investigate the correlation between biofilm formation and antibiotic resistance in Staphylococcus spp. isolates using phenotypic methods. One hundred and eighty (n = 180) isolates were included in the study, with S. epidermidis (40.0%) and S. lugdunensis (10.0%) being the most numerous. Biofilm-forming capacity was assessed by means of the crystal violet microtiter-plate-based (CV-MTP) method. Methicillin-resistance (MR) was identified in 47.2% (n = 85) of isolates. Among the commonly-used antimicrobials, resistance was highest for clindamycin (51.1%), erythromycin (48.9%) and trimethoprim-sulfamethoxazole (51.1%). Based on the CV-MTP method, n = 13 (7.2%), n = 13 (7.2%), n = 42 (23.3%) and n = 113 (62.3%) staphylococcal isolates were non-biofilm-producing, weak, moderate and strong biofilm producers, respectively. No significant differences in biofilm-formation were shown to be observed on the basis of MR (susceptible (S): 0.881 ± 0.309 vs. resistant (R): 0.890 ± 0.347; p = 0.133) and according to the resistance, to most other antibiotics. Rifampin-resistant isolates were more potent biofilm-producers than their susceptible counterparts (S: 0.802 ± 0.296 vs. R: 1.194 ± 0.221; p = 0.024). The association of the antibiotic-resistant phenotype and biofilm-formation is still inconclusive, due to the heterogeneity of the results in presently available studies; however, the understanding of these mechanisms in Staphylococcus spp. is crucial to appropriately address the therapy and eradication of these pathogens. Full article

Patients’ awareness is critical in medical care, as it can serve as an input into the adjustment of interventions. The aim of study was to explore the level of awareness regarding chronic kidney disease (CKD), its medications, and laboratory investigations among nephrology and urology patients of Quetta. The cross-sectional study was used by adopting and culturally modifying a questionnaire. By convenient sampling technique, a total of 500 questionnaires were self-administered to inpatients, outpatients, and dialysis patients, and 468 responses (response rate 93.6%) were analyzed. Descriptive statistics, inferential statistics, and reliability analysis were performed on SPSS v25. A majority, 50.3% (n = 235), was unaware of symptoms that will develop due to worsening of disease, while 56.2% (n = 263) were unaware of what aggravates their kidney function. Almost half of the affected individuals, 47.4% (n = 222), have no understanding about the long-term prognosis of the disease. The majority of the respondents, 51.5% (n = 248), do not know about the names and usage of medications, and 62.4% (n = 292) were unaware of the medicines that may impair kidney function; more than half, 66.7% (n = 312), were unaware about the necessary laboratory investigations. A strong association between awareness and patient education level was found (p < 0.001). Awareness regarding disease condition, medications, and laboratory investigations of CKD among nephrology and urology patients of Quetta was found out to be low, which needs immediate educational intervention. Full article

The production of biofilms is a critical factor in facilitating the survival of Staphylococcus spp. in vivo and in protecting against various environmental noxa. The possible relationship between the antibiotic-resistant phenotype and biofilm-forming capacity has raised considerable interest. The purpose of the study was to assess the interdependence between biofilm-forming capacity and the antibiotic-resistant phenotype in 299 Staphylococcus spp. (S. aureus n = 143, non-aureus staphylococci [NAS] n = 156) of environmental origin. Antimicrobial susceptibility testing and detection of methicillin resistance (MR) was performed. The capacity of isolates to produce biofilms was assessed using Congo red agar (CRA) plates and a crystal violet microtiter-plate-based (CV-MTP) method. MR was identified in 46.9% of S. aureus and 53.8% of NAS isolates (p > 0.05), with resistance to most commonly used drugs being significantly higher in MR isolates compared to methicillin-susceptible isolates. Resistance rates were highest for clindamycin (57.9%), erythromycin (52.2%) and trimethoprim-sulfamethoxazole (51.1%), while susceptibility was retained for most last-resort drugs. Based on the CRA plates, biofilm was produced by 30.8% of S. aureus and 44.9% of NAS (p = 0.014), while based on the CV-MTP method, 51.7% of S. aureus and 62.8% of NAS were identified as strong biofilm producers, respectively (mean OD₅₇₀ values: S. aureus: 0.779±0.471 vs. NAS: 1.053±0.551; p < 0.001). No significant differences in biofilm formation were observed based on MR (susceptible: 0.824 ± 0.325 vs. resistant: 0.896 ± 0.367; p = 0.101). However, pronounced differences in biofilm formation were identified based on rifampicin susceptibility (S: 0.784 ± 0.281 vs. R: 1.239 ± 0.286; p = 0.011). The mechanistic understanding of the mechanisms Staphylococcus spp. use to withstand harsh environmental and in vivo conditions is crucial to appropriately address the therapy and eradication of these pathogens. Full article

The relationship between the multidrug-resistant (MDR) phenotype and biofilm-forming capacity has been a topic of extensive interest among biomedical scientists, as these two factors may have significant influence on the outcomes of infections. The aim of the present study was to establish a possible relationship between biofilm-forming capacity and the antibiotic-resistant phenotype in clinical Acinetobacter baumannii (A. baumannii) isolates. A total of n = 309 isolates were included in this study. Antimicrobial susceptibility testing and the phenotypic detection of resistance determinants were carried out. The capacity of isolates to produce biofilms was assessed using a crystal violet microtiter-plate-based method. Resistance rates were highest for ciprofloxacin (71.19%; n = 220), levofloxacin (n = 68.61%; n = 212), and trimethoprim-sulfamethoxazole (n = 66.02%; n = 209); 42.72% (n = 132) of isolates were classified as MDR; 22.65% (n = 70) of tested isolates were positive in the modified Hodge-test; the overexpression of efflux pumps had significant effects on the susceptibilities of meropenem, gentamicin, and ciprofloxacin in 14.24% (n = 44), 6.05% (n = 19), and 27.51% (n = 85), respectively; 9.39% (n = 29), 12.29% (n = 38), 22.97% (n = 71), and 55.35% (n = 170) of isolates were non-biofilm-producing and weak, moderate, and strong biofilm producers, respectively. A numerical, but statistically not significant, difference was identified between the MDR and non-MDR isolates regarding their biofilm-forming capacity (MDR: 0.495 ± 0.309 vs. non-MDR: 0.545 ± 0.283; p = 0.072), and no association was seen between resistance to individual antibiotics and biofilm formation. Based on numerical trends, MER-resistant isolates were the strongest biofilm producers (p = 0.067). Our study emphasizes the need for additional experiments to assess the role biofilms have in the pathogenesis of A. baumannii infections. Full article

The reduction in infectious disease morbidity and mortality may be attributed to a variety of factors; however, improved sanitation and public health, and the introduction of vaccines and antibiotics are among the most significant. The development of antimicrobial resistance (AMR) in bacterial pathogens is an expected consequence of evolutionary adaptation to these noxious agents and the widespread use of these drugs has significantly sped up this process. Infections caused by multidrug resistant pathogens are directly associated with worse clinical outcomes, longer hospital stays, excess mortality in the affected patients and an increasing burden and costs on the healthcare infrastructure. The Sustainable Development Goals (SDGs) were published in 2015 by the United Nations to serve as a global blueprint for a better, more equitable, more sustainable life on our planet. The SDGs contextualize AMR as a global public health and societal issue; in addition, the continuing emergence of AMR may limit the attainment on many SDGs. The aim of this mini-review is to provide insight on the interface between attainment of SDGs and the clinical problem of drug resistance in bacteria. Full article

Streptococcus suis (S. suis) is an emerging zoonotic pathogen, demonstrated as an etiological agent in human infections in increasing frequency, including diseases like purulent meningitis, sepsis, uveitis-endophtalmitis and arthritis. Due to the increased availability and utility of novel diagnostic technologies in clinical microbiology, more studies have been published on the epidemiology of S. suis, both in veterinary and human medicine; however, there are no comprehensive data available regarding human S. suis infections from East-Central European countries. As a part of our study, data were collected from the National Bacteriological Surveillance (NBS) system on patients who had at least one positive microbiological result for S. suis, corresponding to an 18-year study period (2002–2019). n = 74 S. suis strains were isolated from invasive human infections, corresponding to 34 patients. The number of affected patients was 1.89 ± 1.53/year (range: 0–5). Most isolates originated from blood culture (63.5%) and cerebrospinal fluid (18.9%) samples. Additionally, we present detailed documentation of three instructive cases from three regions of the country and with three distinctly different outcomes. Hungary has traditional agriculture, the significant portion of which includes the production and consumption of pork meat, with characteristic preparation and consumption customs and unfavorable epidemiological characteristics (alcohol consumption, prevalence of malignant diseases or diabetes), which have all been described as important predisposing factors for the development of serious infections. Clinicians and microbiologist need to be vigilant even in nonendemic areas, especially if the patients have a history of occupational hazards or having close contact with infected pigs. Full article

The significant growth in scientific and technological advancements within the field of dentistry has resulted in a wide range of novel treatment modalities for dentists to use. Photodynamic therapy (PDT) is an emerging, non-invasive treatment method, involving photosensitizers, light of a specific wavelength and the generation of singlet oxygen and reactive oxygen species (ROS) to eliminate unwanted eukaryotic cells (e.g., malignancies in the oral cavity) or pathogenic microorganisms. The aim of this review article is to summarize the history, general concepts, advantages and disadvantages of PDT and to provide examples for current indications of PDT in various subspecialties of dentistry (oral and maxillofacial surgery, oral medicine, endodontics, preventive dentistry, periodontology and implantology), in addition to presenting some images from our own experiences about the clinical success with PDT. Full article

Members of the Actinomyces genus are non-spore-forming, anaerobic, and aerotolerant Gram-positive bacteria that are abundantly found in the oropharynx. They are the causative agents of actinomycosis, a slowly progressing (indolent) infection with non-specific symptoms in its initial phase, and a clinical course of extensive tissue destruction if left untreated. Actinomycoses are considered to be rare; however, reliable epidemiological data on their prevalence is lacking. Herein, we describe two representative and contrasting cases of cervicofacial actinomycosis, where the affected patients had distinctively different backgrounds and medical histories. Identification of the relevant isolates was carried out using matrix-assisted laser desorption/ionization mass spectrometry; antimicrobial susceptibility was performed using E-tests. Cervicofacial actinomycoses are the most frequent form of the disease; isolation and identification of these microorganisms from relevant clinical samples (with or without histological examination) is the gold standard for diagnosis. The therapy of these infections includes surgical debridement and antibiotic therapy, mainly with a penicillin-derivative or clindamycin. Full article