The aim of this study is to evaluate opportunistic pathogenic bacteria of the genus Pseudomonas in anthropogenically impacted bathing waters, primarily focusing on bathing ponds. The findings include the detection of these bacteria, their susceptibility to selected antibiotics, and the determination of the Exotoxin A (exoA) gene using PCR method. P. aeruginosa was present in most samples, albeit in low concentrations (1-14 CFU/100 mL). The presence of P. otitidis, which is associated with ear infection, in this type of bathing water, was not rare (up to 90 CFU/100 mL). This species would not be detected by the standard methods, including tests on acetamid medium, used for P. aeruginosa in water. The isolated strains of P. otitidis lack the exoA gene and exhibited higher resistance to meropenem compared to P. aeruginosa.
- MeSH
- ADP Ribose Transferases genetics MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Drug Resistance, Bacterial MeSH
- Bacterial Proteins genetics MeSH
- Bacterial Toxins genetics MeSH
- Pseudomonas aeruginosa Exotoxin A MeSH
- Exotoxins genetics MeSH
- Virulence Factors genetics MeSH
- Microbial Sensitivity Tests * MeSH
- Water Microbiology * MeSH
- Polymerase Chain Reaction MeSH
- Pseudomonas * genetics isolation & purification classification drug effects MeSH
- Ponds * microbiology MeSH
- Publication type
- Journal Article MeSH
The spread of multidrug-resistant Escherichia coli in healthcare facilities is a global challenge. Hospital-acquired infections produced by Escherichia coli include gastrointestinal, blood-borne, urinary tract, surgical sites, and neonatal infections. Therefore, novel approaches are needed to deal with this pathogen and its rising resistance. The concept of attenuating virulence factors is an alternative strategy that might lead to low levels of resistance and combat this pathogen. A sub-inhibitory concentration (1⁄4 MIC) of sitagliptin and nitazoxanide was used for phenotypic assessments of Escherichia coli virulence factors such as biofilm production, swimming motility, serum resistance, and protease production. Moreover, qRT-PCR was used to determine the impact of sub-MIC of the tested drugs on the relative expression levels of papC, fimH, fliC, kpsMTII, ompT_m, and stcE genes encoding virulence factors in Escherichia coli. Also, an in vivo model was conducted as a confirmatory test. Phenotypically, our findings demonstrated that the tested strains showed a significant decrease in all the tested virulence factors. Moreover, the genotypic results showed a significant downregulation in the relative expression levels of all the tested genes. Besides, the examined drugs were found to be effective in protecting mice against Escherichia coli pathogenesis. Sitagliptin and nitazoxanide exhibited strong anti-virulence activities against Escherichia coli. In addition, it is recommended that they might function as adjuvant in the management of Escherichia coli infections with either conventional antimicrobial agents or alone as alternative treatment measures.
- MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Biofilms drug effects MeSH
- Nitro Compounds MeSH
- Escherichia coli * drug effects pathogenicity genetics MeSH
- Virulence Factors genetics metabolism MeSH
- Escherichia coli Infections * drug therapy microbiology MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Drug Resistance, Multiple, Bacterial MeSH
- Mice MeSH
- Escherichia coli Proteins genetics MeSH
- Sitagliptin Phosphate * pharmacology MeSH
- Thiazoles * pharmacology MeSH
- Virulence drug effects MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Escherichia coli is a significant pathogen in extraintestinal infections, and ESBL-producing E. coli poses a major clinical challenge due to its antibiotic resistance. This study comprehensively analyzed E. coli isolates from urine and blood samples of patients with urinary tract and bloodstream infections at three major tertiary hospitals in South Korea. The goal was to provide insights into the distribution, antibiotic resistance, and virulence factors of these strains. Our analysis identified CTX-M and TEM as the dominant ESBL types, found in 71.7% and 61.7% of isolates, respectively, with 46.7% showing co-occurrence. Multilocus sequence typing (MLST) revealed the predominance of high-risk clones such as ST131, ST69, ST73, and ST95, with rare sequence types like ST410 and ST405 also identified. The high prevalence of virulence factors, including iutA (80.8%) and kpsMII (74.2%), further highlights the complexity of these strains. In addition, 38.3% of clinical isolates contained a combination of siderophore, adhesin, protectin, and toxin-related genes. There was no significant difference between urinary tract and bloodstream infections or regional differentiation in Korea. This study highlights the importance of controlling ESBL-producing E. coli infections, especially given the increasing incidence among patients with underlying medical conditions and older adults who are more susceptible to urinary tract infections. These findings serve as valuable indicators for pathogen analysis, especially those harboring antibiotic resistance and toxin genes. The insights gained are expected to contribute significantly to the development of infectious disease prevention and control strategies.
- MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Bacteremia * microbiology epidemiology MeSH
- beta-Lactamases * genetics metabolism MeSH
- Adult MeSH
- Escherichia coli * genetics isolation & purification pathogenicity enzymology drug effects classification MeSH
- Virulence Factors genetics MeSH
- Urinary Tract Infections * microbiology epidemiology MeSH
- Escherichia coli Infections * microbiology epidemiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Young Adult MeSH
- Multilocus Sequence Typing MeSH
- Prevalence MeSH
- Escherichia coli Proteins genetics metabolism MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Virulence MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Republic of Korea MeSH
Despite the lower virulence of current SARS-CoV-2 variants and high rates of vaccinated and previously infected subjects, COVID-19 remains a persistent threat in kidney transplant recipients (KTRs). This study evaluated the parameters of anti-SARS-CoV-2 antibody production in 120 KTRs. The production of neutralizing antibodies in KTRs, following booster vaccination with the mRNA vaccine BNT162b2, was significantly decreased and their decline was faster than in healthy subjects. Factors predisposing to the downregulation of anti-SARS-CoV-2 neutralizing antibodies included age, lower estimated glomerular filtration rate, and a full dose of mycophenolate mofetil. Neutralizing antibodies correlated with those targeting the SARS-CoV-2 receptor binding domain (RBD), SARS-CoV-2 Spike trimmer, total SARS-CoV-2 S1 protein, as well as with antibodies to the deadly SARS-CoV-1 virus. No cross-reactivity was found with antibodies against seasonal coronaviruses. KTRs exhibited lower postvaccination production of neutralizing antibodies against SARS-CoV-2; however, the specificity of their humoral response did not differ compared to healthy subjects.
- MeSH
- COVID-19 * immunology prevention & control MeSH
- Adult MeSH
- Spike Glycoprotein, Coronavirus immunology MeSH
- Immunity, Humoral MeSH
- Middle Aged MeSH
- Humans MeSH
- Antibodies, Neutralizing * blood immunology MeSH
- Transplant Recipients * MeSH
- Antibodies, Viral * blood immunology MeSH
- SARS-CoV-2 * immunology MeSH
- Immunization, Secondary MeSH
- Aged MeSH
- Kidney Transplantation * adverse effects MeSH
- BNT162 Vaccine immunology administration & dosage MeSH
- COVID-19 Vaccines immunology administration & dosage MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
A Mycobacterium smegmatis transcriptional regulator, MSMEG_5850, and its ortholog in M. tuberculosis, rv0775 were annotated as putative TetR Family Transcriptional Regulators. Our previous study revealed MSMEG_5850 is involved in global transcriptional regulation in M. smegmatis and the presence of gene product supported the survival of bacteria during nutritional starvation. Phylogenetic analysis showed that MSMEG_5850 diverged early in comparison to its counterparts in virulent strains. Therefore, the expression pattern of MSMEG_5850 and its counterpart, rv0775, was compared during various in-vitro growth and stress conditions. Expression of MSMEG_5850 was induced under different environmental stresses while no change in expression was observed under mid-exponential and stationary phases. No expression of rv0775 was observed under any stress condition tested, while the gene was expressed during the mid-exponential phase that declined in the stationary phase. The effect of MSMEG_5850 on the survival of M. smegmatis under stress conditions and growth pattern was studied using wild type, knockout, and supplemented strain. Deletion of MSMEG_5850 resulted in altered colony morphology, biofilm/pellicle formation, and growth pattern of M. smegmatis. The survival rate of wild-type MSMEG_5850 was higher in comparison to knockout under different environmental stresses. Overall, this study suggested the role of MSMEG_5850 in the growth and adaptation/survival of M. smegmatis under stress conditions.
- MeSH
- Bacterial Proteins * genetics metabolism MeSH
- Biofilms growth & development MeSH
- Phylogeny MeSH
- Stress, Physiological * MeSH
- Microbial Viability MeSH
- Mycobacterium smegmatis * genetics growth & development physiology metabolism MeSH
- Gene Expression Regulation, Bacterial MeSH
- Transcription Factors * genetics metabolism MeSH
- Publication type
- Journal Article MeSH
The objective of this study was to characterize the virulence characteristics of a collection of Klebsiella pneumoniae isolates collected from different clinical sources. A collection of 60 non-repetitive K. pneumoniae isolates, was studied. In vitro, virulence was analyzed by testing the survival of bacteria in pooled human serum. Isolates were typed by MLST. The genomes of 23 K. pneumoniae isolates, representatives of different STs and virulence profiles, were completely sequenced using the Illumina platform. Of note, 26/60 of K. pneumoniae isolates were resistant to killing by complement. Serum-resistant isolates belonged to distinct STs. Analysis of WGS data with VFDB showed the presence of several virulence genes related various virulence functions. Specifically, serum-resistant isolates carried a higher number of ORFs, which were associated with serum resistance, compared to serum-sensitive isolates. Additionally, analysis of WGS data showed the presence of multiple plasmid replicons that could be involved with the spread and acquisition of resistance and virulence genes. In conclusion, analysis of virulence characteristics showed that an important percentage (31.6%) of K. pneumoniae isolates were in vitro virulent by exhibiting resistance to serum. Thus, the presence of several virulence factors, in combination with the presence of multidrug resistance, could challenge antimicrobial therapy of infections caused by such bacteria.
- MeSH
- Virulence Factors * genetics MeSH
- Genome, Bacterial MeSH
- Klebsiella Infections * microbiology genetics MeSH
- Klebsiella pneumoniae * genetics pathogenicity isolation & purification MeSH
- Humans MeSH
- Multilocus Sequence Typing MeSH
- Hospitals MeSH
- Plasmids genetics MeSH
- Whole Genome Sequencing MeSH
- Virulence genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Greece MeSH
BACKGROUND: Bordetella pertussis isolates which do not express some of acellular pertussis vaccine (aPv) antigens, e.g. pertactin (PRN), have been increasingly reported in countries using aPvs. In Finland, primary pertussis vaccination with whole-cell vaccine was replaced by aPv containing pertussis toxin (PT) and filamentous hemagglutinin (FHA) in 2005 and then by aPv containing PT, FHA, and PRN in 2009. We aimed to study alterations in the expression of FHA, PRN, and PT, three antigens included in aPvs and adenylate cyclase toxin (ACT) not included in current aPvs, among Finnish isolates collected during 1991-2020. METHODS: Of 904 isolates collected by the Finnish Reference Laboratory for Pertussis during 1991-2020, 302 were randomly included. An adapted, monoclonal antibody based, antigen expression ELISA, including the culture of B. pertussis in Stainer-Scholte medium, was performed to quantify the expression of ACT, FHA, PRN, and PT of each isolate. ACT activity was also measured for 16 isolates. Arbitrary units were used for comparing levels of each antigen expression of isolates grouped in every five years. FINDINGS: Following the implementation of aPv in 2005, B. pertussis isolates exhibited a 1.75-fold increase for FHA (p < 0.001) and a 1.5-fold increase for ACT (p < 0.0041) expression until 2020. No FHA or ACT deficient isolates were detected. As the number of PRN deficient isolates has significantly increased with the time, the amount of PRN produced by the positive isolates has also started to decrease, especially after the use of aPv containing PRN. During this period, fluctuations in PT expression were observed. INTERPRETATION: The study demonstrated that in response to aPv-induced selection pressure, different types of selection of B. pertussis has occurred. For FHA and ACT, a steady increase in their production is observed, whereas the frequency of PRN deficient isolates is increased with time.
- MeSH
- Vaccines, Acellular immunology MeSH
- Adenylate Cyclase Toxin immunology MeSH
- Antigens, Bacterial * immunology MeSH
- Adhesins, Bacterial MeSH
- Bordetella pertussis * immunology isolation & purification MeSH
- Enzyme-Linked Immunosorbent Assay MeSH
- Virulence Factors, Bordetella immunology MeSH
- Humans MeSH
- Whooping Cough * prevention & control immunology microbiology MeSH
- Pertussis Vaccine * immunology administration & dosage MeSH
- Pertussis Toxin immunology MeSH
- Bacterial Outer Membrane Proteins immunology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Finland MeSH
BACKGROUND: Pseudomonas aeruginosa can proliferate in immunocompromised individuals, forming biofilms that increase antibiotic resistance. This bacterium poses a significant global health risk due to its resistance to human defenses, antibiotics, and various environmental stresses. The objective of this study was to evaluate the antibacterial, anti-biofilm, and anti-quorum sensing activities of galloylquinic acid compounds (GQAs) extracted from Copaifera lucens leaves against clinical isolates of multidrug-resistant (MDR) P. aeruginosa. We have investigated the optimal concentration of GQAs needed to eradicate preexisting biofilms and manage wound infections caused by P. aeruginosa, in vitro and in vivo. RESULTS: Our results revealed that GQAs exhibited 25-40 mm inhibition zone diameters, with 1-4 μg/mL MIC and 2-16 μg/mL MBC values. GQAs interfered with the planktonic mode of P. aeruginosa isolates, and significantly inhibited their growth in the pre-formed biofilm architecture, with MBIC80 and MBEC80 values of 64 μg/mL and 128 μg/mL, respectively. The anti-biofilm effect was confirmed by fluorescence staining and confocal microscopy which showed a dramatic reduction in the cell viability and the biofilm thickness (62.5%), after exposure to 128 μg/mL of GQAs in particular. The scanning electron micrographs showed that GQAs impaired biofilm and bacterial structures by interfering with the biomass and the exopolysaccharides forming the matrix. GQAs also interfered with virulence factors and bacterial motility, where 128 μg/mL of GQAs significantly (p < 0.05) reduced rhamnolipid, pyocyanin, and the swarming motility of the organism which play a vital role in the biofilm formation. GQAs downregulated 89% of the quorum-sensing genes (lasI and lasR, pqsA and pqsR) involved in the biofilm formation. CONCLUSION: GQAs demonstrate significant promise as novel and potent antibiofilm and antivirulence agents against clinical isolates of MDR P. aeruginosa, with substantial potential to enhance wound healing in biofilm-associated infections. This promising antibacterial action positions GQAs as a superior alternative for the treatment of biofilm-associated wound infections, with substantial potential to improve wound healing and mitigate the impact of persistent bacterial infections. CLINICAL TRIAL NUMBER: not applicable.
- MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Biofilms * drug effects growth & development MeSH
- Wound Infection * microbiology drug therapy MeSH
- Humans MeSH
- Plant Leaves chemistry MeSH
- Microbial Sensitivity Tests MeSH
- Drug Resistance, Multiple, Bacterial drug effects MeSH
- Mice MeSH
- Pseudomonas Infections * microbiology drug therapy MeSH
- Pseudomonas aeruginosa * drug effects physiology isolation & purification MeSH
- Quorum Sensing * drug effects MeSH
- Plant Extracts pharmacology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Klebsiella pneumoniae, a Gram-negative bacterium, comprises strains with diverse virulence potentials, ranging from classical to hypervirulent variants. Understanding the genetic basis underlying the virulence disparities between hypervirulent (hvKp) and classical K. pneumoniae (cKp) strains is crucial. hvKp strains are characterized by hypermucoviscosity, attributed to the presence of specific virulence genes and the production of molecules that aid in their ability to survive, evade host immune defenses, and cause infection. In contrast, classical strains exhibit a broader array of antimicrobial resistance determinants, conferring resistance to multiple antibiotics. Although current definitions of hvKp incorporate clinical features, phenotypes, and genotypes, identifying hvKp strains in clinical settings remains challenging. Genomic studies have been pivotal and have helped to identify distinct genetic profiles in hvKp strains, including unique virulence plasmids and chromosomal variations, underscoring the genetic diversity within K. pneumoniae populations. This review examines the virulence and genetic determinants associated with hvKp. The presence of genes defining hypervirulence, alongside considerations of their utility as biomarkers and targets for therapeutic strategies, is discussed, while also providing insight into biofilm formation by hvKp and key questions that need urgent responses in understanding hvKp.
- MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Biofilms growth & development MeSH
- Virulence Factors * genetics MeSH
- Klebsiella Infections * microbiology MeSH
- Klebsiella pneumoniae * pathogenicity genetics drug effects MeSH
- Humans MeSH
- Virulence genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Medical students are exposed to the hospital environment and patients during their studies, increasing the risk of exposure to virulent and antibiotic-resistant isolates of Staphylococcus aureus. The aim of the study is to determine the prevalence of Staphylococcus aureus among medical students who have varying levels of exposure to the hospital environment to provide valuable insights into the risk of colonization and transmission. Nasal swabs and fingerprints were obtained and cultured on a selective medium for staphylococci. The obtained isolates were confirmed as methicillin-sensitive S. aureus (MSSA) or methicillin-resistant (MRSA) using PCR. Antibiotic resistance, the presence of virulence genes including enterotoxin encoding genes, and spa typing were performed. Among pre-clinical students, MSSA was detected on the nose in 45.2% and on the fingerprints in 10.6% of the participants. Among clinical students, MSSA was detected on the nose in 42.0% and on the fingerprints in 25.4%. Only one MRSA isolate was obtained. Genes seg and sei were the most frequently detected in both student groups, with their presence in over 40% of isolates among clinical students. The eta and etb genes were mainly detected from the nose in both student groups. In pre-clinical students, S. aureus carrying eta gene occurred in 6.4% and etb in 8.5%. In clinical students, the occurrence was 5.1% for eta and 8.5% for etb. The tst gene was identified only in the nose and fingerprints of the clinical student group. The most frequently observed resistance was to clindamycin and erythromycin. In total 58 different spa types were identified. High rates of asymptomatic MSSA carriage were observed in both groups of medical students. Detected MSSA strains showed a high degree of genetic variability, with a number of them carrying the virulence and antibiotic resistance genes. Although students do not exhibit increased risk to their patient's, increased hygiene is required in asymptomatic carriage personnel. The overall prevalence of MRSA was low, with a minimal risk of spread.
- MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Adult MeSH
- Virulence Factors * genetics MeSH
- Humans MeSH
- Methicillin-Resistant Staphylococcus aureus genetics isolation & purification drug effects classification MeSH
- Microbial Sensitivity Tests MeSH
- Young Adult MeSH
- Carrier State * microbiology epidemiology MeSH
- Prevalence MeSH
- Staphylococcal Infections * microbiology epidemiology MeSH
- Staphylococcus aureus * genetics isolation & purification drug effects classification MeSH
- Students, Medical * MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
