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Antimicrobial Stewardship & Healthcare... 2024and are emerging nosocomial, non-glucose fermenting, Gram-negative pathogens. In this nested case-control trial, independent predictors for infections were...
and are emerging nosocomial, non-glucose fermenting, Gram-negative pathogens. In this nested case-control trial, independent predictors for infections were hemodialysis and recent antibiotic usage (overall), while recent usage of fluoroquinolones, was independently associated with infections. Infections were independently associated with multiple worse outcomes.
PubMed: 38415099
DOI: 10.1017/ash.2024.11 -
BioRxiv : the Preprint Server For... Jul 2023is a Gram-negative emerging opportunistic pathogen often found in respiratory diseases such as cystic fibrosis (CF). Patients with CF experience lifelong polymicrobial...
is a Gram-negative emerging opportunistic pathogen often found in respiratory diseases such as cystic fibrosis (CF). Patients with CF experience lifelong polymicrobial infections of the respiratory mucosa. Our prior work showed that promotes persistence of mouse respiratory infections. As is typical for environmental opportunistic pathogens, has a large genome and a high degree of genetic diversity. In this study, we evaluated the genomic content of , combining short and long read sequencing to construct complete genomes of 10 clinical isolates which were then compared with the larger phylogeny of genomic sequence data, and compared colonization/persistence in vivo, alone and in coinfection with . We found that while the overall genome size and GC content were fairly consistent, there was considerable variability in arrangement and gene content. Similarly, there was significant variability in colonization and persistence in vivo in experimental mouse respiratory infection. Ultimately, this study gives us a greater understanding of the genomic diversity of isolated from patients, and how this genomic diversity relates to interactions with other pulmonary pathogens, and to host disease progression. Identifying the molecular determinants of infection with can facilitate development of novel antimicrobial strategies for a highly drug-resistant pathogen.
PubMed: 37503051
DOI: 10.1101/2023.07.14.549068 -
Medicina (Kaunas, Lithuania) Jan 2024There is a need for information regarding the clinical picture of hemorrhagic pneumonia caused by in patients with hematologic malignancies. In this study, we aimed to... (Meta-Analysis)
Meta-Analysis Review
There is a need for information regarding the clinical picture of hemorrhagic pneumonia caused by in patients with hematologic malignancies. In this study, we aimed to investigate the risk factors associated with hemorrhagic pneumonia caused by : A review of the clinical picture of hemorrhagic pneumonia based on reported cases in the literature was performed. In addition, patients with hematologic malignancies who had a infection were included in the meta-analysis to evaluate risk factors for hemorrhagic pneumonia. : A total of 91 patients had hemorrhagic pneumonia. Acute myeloid leukemia was present in 57 patients (62.6%). Those with bacteremia accounted for 94%, while those with neutropenia accounted for 95% and those with thrombocytopenia accounted for 86.7%. Hemorrhagic pneumonia was a risk factor for mortality of infection in patients with hematologic malignancies. Neutropenia and thrombocytopenia were identified as risk factors for hemorrhagic pneumonia. : bacteremia with hemorrhagic pneumonia in patients with hematologic malignancies is a situation with rapid development and high mortality. Neutropenia and thrombocytopenia were risk factors for hemorrhagic pneumonia in patients with hematologic malignancies and with bacteremia; thus, these patients should be managed with caution.
Topics: Humans; Stenotrophomonas maltophilia; Neutropenia; Hematologic Neoplasms; Pneumonia; Thrombocytopenia; Gram-Negative Bacterial Infections
PubMed: 38256422
DOI: 10.3390/medicina60010162 -
Microbiology Spectrum Aug 2023Wildlife can be a reservoir and source of zoonotic pathogens for humans. For instance, pangolins were considered one of the potential animal reservoirs of SARS-CoV-2....
Wildlife can be a reservoir and source of zoonotic pathogens for humans. For instance, pangolins were considered one of the potential animal reservoirs of SARS-CoV-2. The aim of this study was to assess the prevalence of antimicrobial-resistant species (e.g., extended-spectrum β-lactamase [ESBL]-producing ) and Staphylococcus aureus-related complex and to describe the bacterial community in wild Gabonese pangolins. The pharyngeal colonization of pangolins sold in Gabon ( = 89, 2021 to 2022) was analyzed using culture media selective for ESBL-producing , S. aureus-related complex, Gram-positive bacteria and nonfermenters. Phylogenetic analyses of ESBL-producing was done using core-genome multilocus sequence typing (cgMLST) and compared with publicly available genomes. Patterns of cooccurring species were detected by network analysis. Of the 439 bacterial isolates, the majority of species belonged to the genus Pseudomonas ( = 170), followed by ( = 113) and ( = 37). Three Klebsiella pneumoniae isolates and one Escherichia coli isolate were ESBL-producers, which clustered with human isolates from Nigeria (MLST sequence type 1788 [ST1788]) and Gabon (ST38), respectively. Network analysis revealed a frequent cooccurrence of Stenotrophomonas maltophilia with Pseudomonas putida and Pseudomonas aeruginosa. In conclusion, pangolins can be colonized with human-related ESBL-producing K. pneumoniae and E. coli. Unlike in other African wildlife, S. aureus-related complex was not detected in pangolins. There is an ongoing debate if pangolins are a relevant reservoir for viruses such as SARS-CoV-2. Here, we wanted to know if African pangolins are colonized with bacteria that are relevant for human health. A wildlife reservoir of antimicrobial resistance would be of medical relevance in regions were consumption of so-called bushmeat is common. In 89 pangolins, we found three ESBL-producing Klebsiella pneumoniae strains and one ESBL-producing Escherichia coli strains, which were closely related to isolates from humans in Africa. This points toward either a transmission between pangolins and humans or a common source from which both humans and pangolins became colonized.
Topics: Animals; Humans; Anti-Bacterial Agents; Escherichia coli; Pangolins; Multilocus Sequence Typing; Gabon; Staphylococcus aureus; Phylogeny; beta-Lactamases; Drug Resistance, Bacterial; COVID-19; SARS-CoV-2; Escherichia coli Infections; Klebsiella pneumoniae; Bacteria; Microbial Sensitivity Tests
PubMed: 37338382
DOI: 10.1128/spectrum.00664-23 -
Frontiers in Plant Science 2024Microbial biofertilizers or biocontrol agents are potential sustainable approaches to overcome the limitations of conventional agricultural practice. However, the...
INTRODUCTION
Microbial biofertilizers or biocontrol agents are potential sustainable approaches to overcome the limitations of conventional agricultural practice. However, the limited catalog of microbial candidates for diversified crops creates hurdles in successfully implementing sustainable agriculture for increasing global/local populations. The present study aimed to explore the wheat rhizosphere microbiota for microbial strains with a biofertilizer and biocontrol potential.
METHODS
Using a microbial culturing-based approach, 12 unique microbial isolates were identified and screened for biofertilizer/biocontrol potential using genomics and physiological experimentations.
RESULTS AND DISCUSSION
Molecular, physiological, and phylogenetic characterization identified BCM as a potential microbial candidate for sustainable agriculture. BCM was identified as a coccus-shaped gram-negative microbe having optimal growth at 37°C in a partially alkaline environment (pH 8.0) with a proliferation time of ~67 minutes. The stress response physiology of BCM indicates its successful survival in dynamic environmental conditions. It significantly increased (P <0.05) the wheat seed germination percentage in the presence of phytopathogens and saline conditions. Genomic characterization decoded the presence of genes involved in plant growth promotion, nutrient assimilation, and antimicrobial activity. Experimental evidence also correlates with genomic insights to explain the potential of BCM as a potential biofertilizer and biocontrol agent. With these properties, BCM could sustainably promote wheat production to ensure food security for the increasing population, especially in native wheat-consuming areas.
PubMed: 38501138
DOI: 10.3389/fpls.2024.1364807 -
Scientific Reports Jun 2024Stenotrophomonas maltophilia is a nonfermenting gram-negative bacterium associated with multiple nosocomial outbreaks. Antibiotic resistance increases healthcare costs,...
Stenotrophomonas maltophilia is a nonfermenting gram-negative bacterium associated with multiple nosocomial outbreaks. Antibiotic resistance increases healthcare costs, disease severity, and mortality. Multidrug-resistant infections (such as S. maltophilia infection) are difficult to treat with conventional antimicrobials. This study aimed to investigate the isolation rates, and resistance trends of S. maltophilia infections over the past 19 years, and provide future projections until 2030. In total, 4466 patients with S. maltophilia infection were identified. The adult and main surgical intensive care unit (ICU) had the highest numbers of patients (32.2%), followed by the cardiology department (29.8%), and the paediatric ICU (10%). The prevalence of S. maltophilia isolation increased from 7% [95% confidence interval (CI) 6.3-7.7%] in 2004-2007 to 15% [95% CI 10.7-19.9%] in 2020-2022. Most S. maltophilia isolates were resistant to ceftazidime (72.5%), levofloxacin (56%), and trimethoprim-sulfamethoxazole (14.05%), according to our study. A consistent and significant difference was found between S. maltophilia-positive ICU patients and non-ICU patients (P = 0.0017) during the three-year pandemic of COVID-19 (2019-2021). The prevalence of S. maltophilia isolates is expected to reach 15.08% [95% CI 12.58-17.59%] by 2030. Swift global action is needed to address this growing issue; healthcare authorities must set priorities and monitor infection escalations and treatment shortages.
Topics: Stenotrophomonas maltophilia; Humans; Gram-Negative Bacterial Infections; Retrospective Studies; Prevalence; Anti-Bacterial Agents; Male; Female; Adult; Microbial Sensitivity Tests; Middle Aged; Drug Resistance, Multiple, Bacterial; Intensive Care Units; COVID-19; Child; Drug Resistance, Bacterial; Aged; Cross Infection
PubMed: 38914597
DOI: 10.1038/s41598-024-65509-z -
AMB Express May 2024L-asparaginase is an important therapeutic enzyme that is frequently utilized in the chemotherapy regimens of adults as well as pediatric patients with acute...
L-asparaginase is an important therapeutic enzyme that is frequently utilized in the chemotherapy regimens of adults as well as pediatric patients with acute lymphoblastic leukemia. However, a high rate of hypersensitivity with prolonged use has limited its utilization. Stenotrophomonas maltophilia (S. maltophilia) EMCC2297 isolate was reported as a novel and promising source for L- asparaginase. The present study aimed at the production, purification, and characterization of L- asparaginase from S. maltophilia EMCC2297 isolate. The microbial production of L-asparaginase by the test isolate could be increased by pre-exposure to chloramphenicol at 200 µg/ml concentration. S. maltophilia EMCC2297 L-asparaginase could be purified to homogeneity by ammonium sulphate precipitation and the purified form obtained by gel exclusion chromatography showed total activity of 96.4375 IU/ml and specific activity of 36.251 IU/mg protein. SDS-PAGE analysis revealed that the purified form of the enzyme is separated at an apparent molecular weight of 17 KDa. Michaelis-Menten constant analysis showed a Km value of 4.16 × 10 M with L-asparagine as substrate and Vmax of 10.67 IU/ml. The antitumor activity of the purified enzyme was evaluated on different cell lines and revealed low IC50 of 2.2 IU/ml and 2.83 IU/ml for Hepatocellular cancer cell line (HepG-2), human leukemia cancer cell line (K-562), respectively whereas no cytotoxic effect could be detected on normal human lung fibroblast cells (MRC-5). However, mice treated with native L-asparaginase showed lower IgG titre compared to commercial L-asparaginase. This study highlights the promising characteristics of this enzyme making it a valuable candidate for further research and development to be an adduct in cancer chemotherapy.
PubMed: 38704453
DOI: 10.1186/s13568-024-01700-9 -
PeerJ 2024Confronting the environmental threat posed by textile dyes, this study highlights bioremediation as a pivotal solution to mitigate the impacts of Crystal Violet, a...
Confronting the environmental threat posed by textile dyes, this study highlights bioremediation as a pivotal solution to mitigate the impacts of Crystal Violet, a widely-utilized triphenylmethane dye known for its mutagenic and mitotic toxicity. We isolated and identified several bacterial strains capable of degrading Crystal Violet under various environmental conditions. Newly identified strains, including , sp., , , and demonstrated significant decolorization activity of Crystal Violet, complementing the already known capabilities of . Initial experiments using crude extracts confirmed their degradation potential, followed by detailed studies that investigated the impact of different pH levels and temperatures on some strains' degradation efficiency. Depending on the bacteria, the degree of activity change according to pH and temperature was different. At 37 °C, sp. and exhibited higher degradation activity compared to 25 °C, while and did not exhibit a statistically significant difference between the two temperatures. performed optimally at pH 8, while showed high activity at pH 5. s activity remained consistent across the pH range. These findings not only underscore the effectiveness of these bacteria as agents for Crystal Violet degradation but also pave the way for their application in large-scale bioremediation processes for the treatment of textile effluents, marking them as vital to environmental sustainability efforts.
Topics: Biodegradation, Environmental; Gentian Violet; Hydrogen-Ion Concentration; Temperature; Pseudomonas; Stenotrophomonas maltophilia; Coloring Agents; Bacteria
PubMed: 38818456
DOI: 10.7717/peerj.17442 -
Journal of Ophthalmic Inflammation and... Feb 2024To describe a puzzling case of endophthalmitis caused by three unusual bacteria after intravitreal injection, its outcome, and underlying questions.
PURPOSE
To describe a puzzling case of endophthalmitis caused by three unusual bacteria after intravitreal injection, its outcome, and underlying questions.
FINDINGS
A 70-year-old female patient was diagnosed with acute endophthalmitis following intravitreal aflibercept injection for age-related macular degeneration. A standard tap and inject procedure was performed. Microbiological analyses on the anterior chamber and vitreous samples yielded the presence of three non-fermenting Gram-negative rods: Pseudomonas stutzeri, Stenotrophomonas maltophilia, and Ochrobactrum anthropi. The outcome was favorable after intravitreal injections of vancomycin and ceftazidime, with an almost complete recovery of the visual acuity to its baseline level. No potential source of infection was identified.
CONCLUSION
Endophthalmitis following intravitreal injection can be caused by a wide variety of bacteria, including some rare Gram-negative species. They can sometimes co-exist in a single patient, but their virulence may vary greatly. Due to the variable antibiotic susceptibility and frequent multiresistance associated with non-fermenting Gram-negative rods, a prompt microbiological approach is required. Favorable outcome can be achieved with standard management.
PubMed: 38334879
DOI: 10.1186/s12348-023-00376-9 -
European Journal of Microbiology &... May 2024Extensive use of carbapenems may lead to selection pressure for Stenotrophomonas maltophilia (SM) in hospital environments. The aim of our study was to assess the...
Extensive use of carbapenems may lead to selection pressure for Stenotrophomonas maltophilia (SM) in hospital environments. The aim of our study was to assess the possible association between systemic antibiotic use and the incidence of SM. A retrospective, observational study was carried out in a tertiary-care hospital in Hungary, between January 1st 2010 and December 31st 2019. Incidence-density for SM and SM resistant to trimethoprim-sulfamethoxazole (SXT) was standardized for 1000 patient-days, while systemic antibiotic use was expressed as defined daily doses (DDDs) per 100 patient-days. Mean incidence density for SM infections was 0.42/1000 patient-days; 11.08% were were resistant to SXT, the mean incidence density for SXT-resistant SM was 0.047/1000 patient-days. Consumption rate for colistin, glycopeptides and carbapenems increased by 258.82, 278.94 and 372.72% from 2010 to 2019, respectively. Strong and significant positive correlations were observed with the consumption of carbapenems (r: 0.8759; P < 0.001 and r: 0.8968; P < 0.001), SXT (r: 0.7552; P = 0.011 and r: 0.7004; P = 0.024), and glycopeptides (r: 0.7542; P = 0.012 and r: 0.8138; P < 0.001) with SM and SXT-resistant SM incidence-density/1000 patient-days, respectively. Implementation of institutional carbapenem-sparing strategies are critical in preserving these life-saving drugs, and may affect the microbial spectrum of infections in clinical settings.
PubMed: 38441614
DOI: 10.1556/1886.2024.00022