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JAC-antimicrobial Resistance Aug 2023The global Study of Monitoring Antimicrobial Resistance Trends (SMART) is a surveillance program for evaluation of antimicrobial resistance (AMR) in Gram-negative...
The epidemiology and microbiological characteristics of infections caused by Gram-negative bacteria in Qatar: national surveillance from the Study for Monitoring of Antimicrobial Resistance Trends (SMART): 2017 to 2019.
BACKGROUND
The global Study of Monitoring Antimicrobial Resistance Trends (SMART) is a surveillance program for evaluation of antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) from different regions including Gulf countries.
OBJECTIVES
To evaluate AMR in GNB from various clinical specimens including microbiological and genetic characteristics for existing and novel antimicrobials.
METHODS
A prospective study was conducted on clinical specimens from Hamad Medical Corporation, Qatar, between 2017 and 2019 according to the SMART protocol. Consecutive GNB from different sites were evaluated including lower respiratory, urinary tract, intrabdominal and bloodstream infections.
RESULTS
Over the 3 years study period, 748 isolates were evaluated from the specified sites comprising 37 different GNB outlining four key pathogens: , , and .For the two major pathogens and , phenotypic ESBL was identified in 55.77% (116/208) compared to 39% (73/187), while meropenem resistance was 3.8% compared to 12.8% and imipenem/relebactam resistance was 2.97% compared to 11.76%, respectively. The overall ceftolozane/tazobactam resistance for was 9.6% (20/208) compared to 14.97% (28/187) for while resistance for ceftazidime/avibactam was 3.65% (5/137) and 5.98% (10/117), respectively. Genomic characteristics of 70 Enterobacterales including 48 carbapenem-resistant, revealed prevalence of β-lactamases from all classes, predominated by while carbapenem resistance revealed paucity of and dominance of and resistance genes.
CONCLUSIONS
Surveillance of GNB from Qatar showed prevalence of key pathogens similar to other regions but demonstrated significant resistance patterns to existing and novel antimicrobials with different underlying resistance mechanisms.
PubMed: 37546546
DOI: 10.1093/jacamr/dlad086 -
Microbiology Spectrum Dec 2023In the past, studies have focused on bacterial pathogenicity in mono-species infections, in part ignoring the clinical relevance of diseases caused by more than one...
In the past, studies have focused on bacterial pathogenicity in mono-species infections, in part ignoring the clinical relevance of diseases caused by more than one pathogen (i.e., polymicrobial infections). However, it is now common knowledge that multiple bacteria species are often involved in the course of an infection. For treatment of such infections, it is absolutely important to understand the dynamics of species interactions at possible infection sites and the molecular mechanisms behind these interactions. Here, we studied the impact of on its commensals and in multispecies biofilms. We analyzed the 3D structural architectures of dual- and triple-species biofilms, niche formation within the biofilms, and the interspecies interactions on a molecular level. RNAseq data identified key genes involved in multispecies biofilm formation and interaction as potential drug targets for the clinical combat of multispecies infection with these major pathogens.
Topics: Humans; Pseudomonas aeruginosa; Staphylococcus aureus; Stenotrophomonas maltophilia; Transcriptome; Staphylococcal Infections; Pseudomonas Infections; Biofilms
PubMed: 37819084
DOI: 10.1128/spectrum.00859-23 -
MicrobiologyOpen Jun 2024Stenotrophomonas maltophilia is a multidrug-resistant (MDR), Gram-negative bacterium intrinsically resistant to beta-lactams, including last-resort carbapenems. As an...
Stenotrophomonas maltophilia is a multidrug-resistant (MDR), Gram-negative bacterium intrinsically resistant to beta-lactams, including last-resort carbapenems. As an opportunistic pathogen, it can cause serious healthcare-related infections. This study assesses the prevalence, resistance profiles, and genetic diversity of S. maltophilia isolated from residential aged care facilities (RACFs). RACFs are known for their overuse and often inappropriate use of antibiotics, creating a strong selective environment that favors the development of bacterial resistance. The study was conducted on 73 S. maltophilia isolates recovered from wastewater and facility swab samples obtained from three RACFs and a retirement village. Phenotypic and genotypic assessments of the isolates revealed high carbapenem resistance, exemplifying their intrinsic beta-lactam resistance. Alarmingly, 49.3% (36/73) of the isolates were non-wild type for colistin, with minimum inhibitory concentration values of > 4 mg/L, and 11.0% (8/73) were resistant to trimethoprim-sulfamethoxazole. No resistance mechanisms were detected for either antimicrobial. Genotypic assessment of known lineages revealed isolates clustering with Sm17 and Sm18, lineages not previously reported in Australia, suggesting the potential ongoing spread of MDR S. maltophilia. Lastly, although only a few isolates were biocide tolerant (2.7%, 2/73), their ability to grow in high concentrations (64 mg/L) of triclosan is concerning, as it may be selecting for their survival and continued dissemination.
Topics: Stenotrophomonas maltophilia; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Humans; Anti-Bacterial Agents; Gram-Negative Bacterial Infections; Genotype; Australia; Wastewater; Prevalence; Genetic Variation; Colistin; Carbapenems; Aged; Residential Facilities
PubMed: 38682784
DOI: 10.1002/mbo3.1409 -
Diagnostic value of loop-mediated isothermal amplification in detecting lower respiratory pathogens.Journal of Infection in Developing... Jul 2023To investigate the diagnostic value of loop-mediated thermostatic amplification (LAMP) in detecting pathogenic bacteria from bronchoalveolar lavage fluid (BALF) of...
INTRODUCTION
To investigate the diagnostic value of loop-mediated thermostatic amplification (LAMP) in detecting pathogenic bacteria from bronchoalveolar lavage fluid (BALF) of patients with pulmonary disorders combined with lower respiratory tract infections (LRTI).
METHODOLOGY
This cross-sectional study included patients with pulmonary disorders combined with LRTI, including chronic obstructive pulmonary disease (COPD), bronchiectasis, or lung cancer, hospitalized in Meizhou People's Hospital between January 2020 and October 2021. BALF was collected using local bronchoalveolar lavage and electronic bronchoscopy. The presence of the pathogens was confirmed using the LAMP method and the bacterial culture method.
RESULTS
In total, 249 patients were included (135 with COPD, 73 with bronchiectasis, and 41 with lung cancer). The proportions of Methicillin-resistant Staphylococcus aureus (4.8% vs 0.4%, p = 0.02) and Haemophilus influenzae (6.8% vs 0.4%, p < 0.001) detected by the LAMP method was higher, while the proportion of Pseudomonas aeruginosa was lower compared with that of the culture method (6.8% vs 12.4%, p = 0.034). The bacterial species with the highest agreement coefficient was Stenotrophomonas maltophilia (Kappa = 0.798, p < 0.001). Furthermore, 9 COPD patients exhibited mixed infections as determined by the LAMP method, whereas the culture method detected only 2 of these cases (1.48%) (p < 0.05).
CONCLUSIONS
LAMP can detect more pathogenic bacteria, notably Haemophilus influenza, Methicillin-resistant Staphylococcus aureus, and atypical pathogens in patients with clinically common pulmonary disorders combined with LRTI. LAMP may provide etiological evidence to guide the clinical use of antibiotics in primary hospitals.
Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Cross-Sectional Studies; Respiratory Tract Infections; Bacteria; Pulmonary Disease, Chronic Obstructive; Bronchiectasis; Lung Neoplasms
PubMed: 37515790
DOI: 10.3855/jidc.17797 -
Frontiers in Cellular and Infection... 2024is a prominent genus owing to its dual nature. Species of this genus have many applications in industry and agriculture as plant growth-promoting rhizobacteria and...
INTRODUCTION
is a prominent genus owing to its dual nature. Species of this genus have many applications in industry and agriculture as plant growth-promoting rhizobacteria and microbial biological control agents, whereas species such as are considered one of the leading gram-negative multi-drug-resistant bacterial pathogens because of their high contribution to the increase in crude mortality and significant clinical challenge. Pathogenic species and most clinical isolates belong to the complex (SMc). However, a strain highly homologous to was isolated from a patient with pulmonary tuberculosis (TB), which aroused our interest, as belongs to a relatively distant clade from SMc and there have been no human association reports.
METHODS
The pathogenicity, immunological and biochemical characteristics of 610A2 were systematically evaluated.
RESULTS
610A2 is a new species of genus , which is named as sp. nov. for its obvious brown water-soluble pigment. 610A2 is pathogenic and caused significant weight loss, pulmonary congestion, and blood transmission in mice because it has multiple virulence factors, haemolysis, and strong biofilm formation abilities. In addition, the cytokine response induced by this strain was similar to that observed in patients with TB, and the strain was resistant to half of the anti-TB drugs.
CONCLUSIONS
The pathogenicity of 610A2 may not be weaker than that of . Its isolation extended the opportunistic pathogenic species to all 3 major clades of the genus , indicating that the clinical importance of species of other than and potential risks to biological safety associated with the use of require more attention.
Topics: Stenotrophomonas; Animals; Phylogeny; Gram-Negative Bacterial Infections; Biofilms; Mice; Virulence Factors; RNA, Ribosomal, 16S; Humans; DNA, Bacterial; Sequence Analysis, DNA; Disease Models, Animal; Hemolysis; Bacterial Typing Techniques
PubMed: 38903940
DOI: 10.3389/fcimb.2024.1410385 -
Acute and Critical Care Nov 2023Stenotrophomonas maltophilia has been increasingly recognized as an opportunistic pathogen associated with high morbidity and mortality. Data on the prognostic factors...
BACKGROUND
Stenotrophomonas maltophilia has been increasingly recognized as an opportunistic pathogen associated with high morbidity and mortality. Data on the prognostic factors associated with S. maltophilia pneumonia in patients admitted to intensive care unit (ICU) are lacking.
METHODS
We conducted a retrospective analysis of data from 117 patients with S. maltophilia pneumonia admitted to the ICUs of two tertiary referral hospitals in South Korea between January 2011 and December 2022. To assess risk factors associated with in-hospital mortality, multivariable logistic regression analyses were performed.
RESULTS
The median age of the study population was 71 years. Ventilator-associated pneumonia was 76.1% of cases, and the median length of ICU stay before the first isolation of S. maltophilia was 15 days. The overall in-hospital mortality rate was 82.1%, and factors independently associated with mortality were age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.00-1.09; P=0.046), Sequential Organ Failure Assessment (SOFA) score (OR, 1.21; 95%; CI, 1.02-1.43; P=0.025), corticosteroid use (OR, 4.19; 95% CI, 1.26-13.91; P=0.019), and polymicrobial infection (OR, 95% CI 0.07-0.69). However, the impact of appropriate antibiotic therapy on mortality was insignificant. In a subgroup of patients who received appropriate antibiotic therapy (n=58), antibiotic treatment modality-related variables, including combination or empirical therapy, also showed no significant association with survival.
CONCLUSIONS
Patients with S. maltophilia pneumonia in ICU have high mortality rates. Older age, higher SOFA score, and corticosteroid use were independently associated with increased in-hospital mortality, whereas polymicrobial infection was associated with lower mortality. The effect of appropriate antibiotic therapy on prognosis was insignificant.
PubMed: 37994018
DOI: 10.4266/acc.2023.00682 -
Journal of Cystic Fibrosis : Official... Sep 2023Regular surveillance microbiology of sputum is used in cystic fibrosis (CF) to monitor for new pathogens and target treatments. A move to remote clinics has meant...
BACKGROUND
Regular surveillance microbiology of sputum is used in cystic fibrosis (CF) to monitor for new pathogens and target treatments. A move to remote clinics has meant greater reliance on samples collected at home and posted back. The impact of delays and sample disruption caused by posting has not been systematically assessed but could have significant implications for CF microbiology.
METHODS
Sputum samples collected from adult CF patients were mixed, split, and either processed immediately or posted back to laboratory. Processing involved a further split into aliquots for culture-dependant and-independent microbiology (quantitative PCR [QPCR] and microbiota sequencing). We calculated retrieval by both approaches for five typical CF pathogens: Pseudomonas aeruginosa, Burkholderia cepacia complex, Achromobacter xylosoxidans, Staphylococcus aureus and Stenotrophomonas maltophilia.
RESULTS
93 paired samples were collected from 73 CF patients. Median interval between sample posting and receipt was 5 days (range 1-10). For culture, overall concordance for posted and fresh samples was 86% across the five targeted pathogens (ranging from 57 to 100% for different organisms), with no bias towards either sample type. For QPCR, overall concordance was 62% (range 39-84%), again with no bias towards fresh or posted samples. There were no significant differences in culture or QPCR for samples with short (≤3days) versus extended (≥7days) postal delays. Posting had no significant impact on pathogen abundance nor on microbiota characteristics.
CONCLUSIONS
Posted sputum samples reliably reproduced culture-based and molecular microbiology of freshly collected samples, even after prolonged delays at ambient conditions. This supports use of posted samples during remote monitoring.
Topics: Adult; Humans; Cystic Fibrosis; Sputum; Pseudomonas aeruginosa; Staphylococcal Infections; Microbiota
PubMed: 36934050
DOI: 10.1016/j.jcf.2023.03.008 -
Antibiotics (Basel, Switzerland) Nov 2023The study examines the antibiotic resistance of metal-tolerant bacteria isolated from the wastewater treatment plant of a large city to six antibiotics belonging to the...
The study examines the antibiotic resistance of metal-tolerant bacteria isolated from the wastewater treatment plant of a large city to six antibiotics belonging to the β-lactam antibiotics, aminoglycosides and amphenicols. Resistance of bacteria from sewage sludge multitolerant to heavy metals to 18 antibiotics of the β-lactam antibiotics, tetracyclines, aminoglycosides, diaminopyrimidines, amphenicols and ansamycins was studied also. Out of 10, the metal-tolerant microorganisms isolated from wastewater treatment facilities only the strain (tolerant to 3 mM Cu) from the sludge of a secondary settling tank did not show resistance to the studied antibiotics at the concentrations considered. Resistance to the maximum amount of antibiotics was typical for strains SS0-1, isolated from fresh sewage sludge and resistant to 5 mmol Cu and 3 mmol Pb, or SS0-5, also isolated from fresh sludge and resistant to 3 mmol Zn and Cu. It is possible that bacterial resistance to antibiotics develops not only as a result of the use of antibiotics themselves, but also as a result of environmental pollution with heavy metals, and vice versa.
PubMed: 38136714
DOI: 10.3390/antibiotics12121678 -
Annals of Hematology May 2024Stenotrophomonas maltophilia (SM) bloodstream infections (BSIs) contribute to significant mortality in hematologic malignancy (HM) and hematopoietic stem cell...
Stenotrophomonas maltophilia (SM) bloodstream infections (BSIs) contribute to significant mortality in hematologic malignancy (HM) and hematopoietic stem cell transplantation (HSCT) patients. A risk score to predict SM BSI could reduce time to appropriate antimicrobial therapy (TTAT) and improve patient outcomes. A single center cohort study of hospitalized adults with HM/HSCT was conducted. Patients had ≥ 1 blood culture with a Gram-negative (GN) organism. A StenoSCORE was calculated for each patient. The StenoSCORE2 was developed using risk factors for SM BSI identified via logistic regression. Receiver operating characteristic (ROC) curves were plotted. Sensitivity and specificity for the StenoSCORE and StenoSCORE2 were calculated. Thirty-six SM patients and 534 non-SM patients were assessed. A StenoSCORE ≥ 33 points was 80% sensitive, 68% specific, and accurately classified 69% of GN BSIs. StenoSCORE2 variables included acute leukemia, prolonged neutropenia, mucositis, ICU admission, recent meropenem and/or cefepime exposure. The StenoSCORE2 performed better than the StenoSCORE (ROC AUC 0.84 vs. 0.77). A StenoSCORE2 ≥ 4 points was 86% sensitive, 76% specific, and accurately classified 77% of GN BSIs. TTAT was significantly longer for patients with SM BSI compared with non-SM BSI (45.16 h vs. 0.57 h; p < 0.0001). In-hospital and 28-day mortality were significantly higher for patients with SM BSI compared to non-SM BSI (58.3% vs. 18.5% and 66.7% vs. 26.4%; p-value < 0.0001). The StenoSCORE and StenoSCORE2 performed well in predicting SM BSIs in patients with HM/HSCT and GN BSI. Clinical studies evaluating whether StenoSCORE and/or StenoSCORE2 implementation improves TTAT and clinical outcomes are warranted.
Topics: Adult; Humans; Stenotrophomonas maltophilia; Cohort Studies; Bacteremia; Hematologic Neoplasms; Sepsis; Retrospective Studies; Risk Factors; Gram-Negative Bacterial Infections
PubMed: 38453704
DOI: 10.1007/s00277-024-05686-z -
Foods (Basel, Switzerland) Apr 2024is a major threat to the food industry and human health owing to its strong protease production and biofilm formation abilities. However, information regarding...
is a major threat to the food industry and human health owing to its strong protease production and biofilm formation abilities. However, information regarding regulatory factors or potential mechanisms is limited. Herein, we observed that temperature differentially regulates biofilm formation and protease production, and a cAMP receptor-like protein (Clp) negatively regulates thermosensor biofilm formation, in contrast to protease synthesis. Among four c-di-GMP-related two-component systems (TCSs), promoter fusion analysis revealed that transcription levels were predominantly controlled by LotS/LotR, partially controlled by both RpfC/RpfG and a novel TCS Sm0738/Sm0737, with no obvious effect caused by Sm1912/Sm1911. Biofilm formation in Δ and ΔTCSs strains suggested that LotS/LotR controlled biofilm formation in a Clp-mediated manner, whereas both RpfC/RpfG and Sm0738/Sm0737 may occur in a distinct pathway. Furthermore, enzymatic activity analysis combined with c-di-GMP level indicated that the enzymatic activity of c-di-GMP-related metabolism proteins may not be a vital contributor to changes in c-di-GMP level, thus influencing physiological functions. Our findings elucidate that the regulatory pathway of c-di-GMP-related TCSs and Clp in controlling spoilage or the formation of potentially pathogenic factors in expand the understanding of c-di-GMP metabolism and provide clues to control risk factors of in food safety.
PubMed: 38672874
DOI: 10.3390/foods13081201