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This retrospective study was conducted to evaluate the characteristics and outcomes of patients with ventilator-associated pneumonia (VAP) caused by Stenotrophomonas maltophilia (S. maltophilia), focusing on the impact of appropriate empirical antimicrobial treatment. Of the enrolled 240 patients with VAP due to S. maltophilia (median age: 45 years) in a tertiary-care hospital in southern Thailand between January 2010 and December 2021, 90% had medical comorbidities and 91% had previously received carbapenems. In addition, only 45% of the patients were initially admitted to the intensive care unit. Patients administered appropriate empirical antimicrobial treatment including colistin alone and colistin plus TMP-SMX or fluoroquinolone-based regimens had significantly lower 14-day, 30-day, and in-hospital mortalities, compared with those who did not receive appropriate empirical antimicrobial treatment (21% and 2% vs. 31%; 30% and 5% vs. 44%; and 30% and 12% vs. 53%, respectively). Thus, the use of appropriate empirical antimicrobial treatments led to a significantly reduced length of hospital stay, duration of ventilation, and hospital costs. The current study suggests that the use of appropriate empirical antimicrobial treatment based on susceptibility testing without considering pharmacokinetic properties and administration dosages improves the outcomes of patients with VAP due to S. maltophilia. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia, a non-fermentative, ubiquitous, gram-negative aerobic bacterium, is associated with high mortality rates, particularly in immunocompromised or debilitated patients. The prevalence rate of ICU-acquired pneumonia episodes caused by this microorganism has been found to be 2%. S. maltophilia has been identified as one of the top 10 microorganisms responsible for such infections in EU/EEA countries. This study describes an outbreak of S. maltophilia in an intensive care unit of a hospital in northern Italy. This includes an epidemiological investigation of the cases, the environmental microbiological controls carried out, a comparison of the strains by multilocus sequence typing (MLST), and the measures taken to prevent and control the outbreak. Among the seven clinical isolates of S. maltophilia analyzed herein, six demonstrated susceptibilities to trimethoprim–sulfamethoxazole. Conversely, one isolate of S. maltophilia exhibited resistance to first-line antibiotics. ST was found to be identical for six patients (ST 4), as well as in the environmental feedback on the trolley of Box 2. The analysis of the temporal and spatial progression of the outbreak has suggested that the transmission of S. maltophilia may have occurred through cross-transmission during care practices. [ABSTRACT FROM AUTHOR]

Abstract Background Mastitis is an inflammatory disease of the mammary gland that has serious economic impacts on the dairy industry and endangers food safety. Our previous study found that the body has a gut/rumen-mammary gland axis and that disturbance of the gut/rumen microbiota could result in ‘gastroenterogenic mastitis’. However, the mechanism has not been fully clarified. Recently, we found that long-term feeding of a high-concentrate diet induced mastitis in dairy cows, and the abundance of Stenotrophomonas maltophilia (S. maltophilia) was significantly increased in both the rumen and milk microbiota. Accordingly, we hypothesized that ‘gastroenterogenic mastitis’ can be induced by the migration of endogenous gut bacteria to the mammary gland. Therefore, this study investigated the mechanism by which enterogenic S. maltophilia induces mastitis. Results First, S. maltophilia was labelled with superfolder GFP and administered to mice via gavage. The results showed that treatment with S. maltophilia promoted the occurrence of mastitis and increased the permeability of the blood-milk barrier, leading to intestinal inflammation and intestinal leakage. Furthermore, tracking of ingested S. maltophilia revealed that S. maltophilia could migrate from the gut to the mammary gland and induce mastitis. Subsequently, mammary gland transcriptome analysis showed that the calcium and AMPK signalling pathways were significantly upregulated in mice treated with S. maltophilia. Then, using mouse mammary epithelial cells (MMECs), we verified that S. maltophilia induces mastitis through activation of the calcium-ROS-AMPK-mTOR-autophagy pathway. Conclusions In conclusion, the results showed that enterogenic S. maltophilia could migrate from the gut to the mammary gland via the gut-mammary axis and activate the calcium-ROS-AMPK-mTOR-autophagy pathway to induce mastitis. Targeting the gut-mammary gland axis may also be an effective method to treat mastitis.

A sudden emergence of Stenotrophomonas maltophilia as a primary pathogen both in immunocompromised and immunocompetent individuals has raised a serious concern, as it is associated with significant case fatality ratio. We intended to study the clinico-microbiological profile of S. maltophilia isolates from various samples and outcome of the infections in a tertiary healthcare center, Pune, India. This is an observational cross-sectional study was conducted from January 2021 to June 2022 at Department of Microbiology of a tertiary care Centre in Pune, India. Of the 12049 samples received for culture, S. maltophilia was isolated in 57 samples. Only 42 samples with pure growth of S. maltophilia were included in the study with 15 excluded due to mixed growth. All isolates were confirmed by VITEK-MS (bioMerieux, SA, France) which uses Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) technology. Of the 42 isolates, majority were isolated from pus(28.6%) and most of patients (61.9%) were from acute health care settings. The isolates had high susceptibility to Cotrimoxazole (85.7%) and Minocycline (85.7%) and low susceptibility to Ceftazidime (45.2%). A case fatality rate of 7.1% (3/42 cases) was noted and 39 cases were discharged after complete treatment. All the three fatal cases were susceptible to levofloxacin, ciprofloxacin, cotrimoxazole and minocycline and all three fatal cases were resistant to ceftazidime. S. maltophilia has recently shown an increase in nosocomial infections especially in acute healthcare settings like ICU and other critical care wards. The isolates of the present study had high susceptibility to trimethoprim-sulfamethoxazole (TMP-SXT) and Minocycline and low susceptible to Ceftazidime.

Introduction: Antimicrobial resistance is a growing problem that necessitates the development of new therapeutic options. Cefiderocol and aztreonam (AT) are often the last active β-lactams for treating metallo-β-lactamases (MBL)-producing Gram-negative bacilli. In these difficult-to-treat bacterial strains, AT resistance is frequently attributed to the co-occurrence of other resistance mechanisms. In the case of β-lactamases they can often be inhibited by avibactam. In the present study, we evaluated the use of the double-disc synergy test (DDST) as a screening tool for the detection of synergy between AT-avibactam (ATA). We validated both the Gradient Diffusion Strips (GDSs) superposition method and the commercially available Liofilchem’s ATA GDS. Materials and methods: We tested AT susceptibility in combination with ceftazidime-avibactam for 65 strains, including 18 Serine-β-Lactamase (SBL)- and 24 MBL-producing Enterobacterales, 12 MBL-producing P. aeruginosa, and 11 S. maltophilia isolates. Interpretation was done with EUCAST breakpoints (version 13.0), AT breakpoints being used for ATA. The accuracy and validity of the GDSs superposition method and ATA GDS were evaluated using an AT GDS applied on Mueller Hinton Agar plates supplemented with avibactam (MH-AV). A DDST was performed to screen for synergy between antibiotic combinations. Results: Using MH-AV, all SBL- and MBL-positive Enterobacterales were susceptible or susceptible at increased exposure to the combination AT-avibactam. In contrast, only 2 out of the 12 (17%) P. aeruginosa strains and 9/11 (82%) of the S. maltophilia strains were susceptible- or susceptible at increased exposure for the combination of AT-avibactam. The DDST detected all synergies, demonstrating a 100% sensitivity and 100% negative predictive value for all bacterial strains. Conclusion: The DDST is a sensitive tool for screening for antibiotic synergy. Unlike S. maltophilia and SBL- and MBL-positive Enterobacterales, most MBLpositive P. aeruginosa strains remain resistant to AT-avibactam. ATA GDS should be preferred for MIC determination of the AT-avibactam combination, while the GDSs superposition method can be used as an alternative to the commercial test. [ABSTRACT FROM AUTHOR]

A sudden emergence of Stenotrophomonas maltophiliaas a primary pathogen both in immunocompromised and immunocompetent individuals has raised a serious concern, as it is associated with significant case fatality ratio. We intended to study the clinico-microbiological profile of S. maltophilia isolates from various samples and outcome of the infections in a tertiary healthcare center, Pune, India. This is an observational cross-sectional study was conducted from January 2021 to June 2022 at Department of Microbiology of a tertiary care Centre in Pune, India. Of the 12049 samples received for culture, S. maltophilia was isolated in 57 samples. Only 42 samples with pure growth of S. maltophilia were included in the study with 15 excluded due to mixed growth. All isolates were confirmed by VITEK-MS (bioMerieux, SA, France) which uses Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) technology. Of the 42 isolates, majority were isolated from pus(28.6%) and most of patients (61.9%) were from acute health care settings. The isolates had high susceptibility to Cotrimoxazole (85.7%) and Minocycline (85.7%) and low susceptibility to Ceftazidime (45.2%). A case fatality rate of 7.1% (3/42 cases) was noted and 39 cases were discharged after complete treatment. All the three fatal cases were susceptible to levofloxacin, ciprofloxacin, cotrimoxazole and minocycline and all three fatal cases were resistant to ceftazidime. S. maltophilia has recently shown an increase in nosocomial infections especially in acute healthcare settings like ICU and other critical care wards. The isolates of the present study had high susceptibility to trimethoprim-sulfamethoxazole (TMP-SXT) and Minocycline and low susceptible to Ceftazidime. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia has been demonstrated herein to reduce CO2 without any cofactor, photon or hydrogen (H2) addition during reaction. S. maltophilia reduces 13CO2 into 13C-labeled formate in batch mode. Two intracellular enzymes are curently being considered for their ability to catalyze the CO2 reduction reaction: a Fe-nitrogenase and a formate dehydrogenase (FeS-FDH). The reaction was intensified by implementing the bacteria in an electrolysis cell continuously fed with CO2. In this configuration, CO2 removal reached up to 25% v/v at 30°C and atmospheric pressure.

Stenotrophomonas maltophilia to istotny czynnik etiologiczny zakażeń u pacjentów z zaburzonym funkcjonowaniem układu immunologicznego, poddanych inwazyjnym zabiegom diagnostycznym i terapeutycznym, z chorobą nowotworową czy mukowiscydozą. Stanowi zagrożenie przede wszystkim dla pacjentów hospitalizowanych. Ze względu na szeroką oporność naturalną, jak i narastającą oporność nabytą terapia zakażeń powodowanych przez ten mikroorganizm stanowi wyzwanie dla współczesnej medycyny. W pracy przedstawiono aktualną wiedzę na temat ogólnej charakterystyki, znaczenia klinicznego i najważniejszych czynników chorobotwórczości pałeczek S. maltophilia. Omówiono możliwości terapeutyczne, również te alternatywne, przy zakażeniach wywołanych przez te drobnoustroje.

ABSTRACT: Objectives: Stenotrophomonas maltophilia (S. maltophilia), an opportunistic pathogen, causes infection in patients undergoing immunosuppressive therapy, mechanical ventilation, or catheters and in long-term hospitalized patients. Due to its extensive resistance to various antibiotics and chemotherapeutic agents, S. maltophilia is challenging to treat. Using case reports, case series, and prevalence studies, the current study provides a systematic review and meta-analysis of antibiotic resistance profiles across clinical isolates of S. maltophilia. Methods: A systematic literature search was performed for original research articles published in Medline, Web of Science, and Embase databases from 2000 to 2022. Statistical analysis was performed using STATA 14 software to report antibiotic resistance of S. maltophilia clinical isolates worldwide. Results: 223 studies (39 case reports/case series and 184 prevalence studies) were collected for analysis. A meta-analysis of prevalence studies demonstrated that the most antibiotic resistance worldwide was to levofloxacin, trimethoprim-sulfamethoxazole (TMP/SMX), and minocycline (14.4%, 9.2%, and 1.4%, respectively). Resistance to TMP/SMX (36.84%), levofloxacin (19.29%), and minocycline (1.75%) were the most prevalent antibiotic resistance types found in evaluated case reports/case series studies. The highest resistance rate to TMP/SMX was reported in Asia (19.29%), Europe (10.52%), and America (7.01%), respectively. Conclusion: Considering the high resistance to TMP/SMX, more attention should be paid to patients’ drug regimens to prevent the emergence of multidrug-resistant S. maltophilia isolates.

This retrospective study was conducted to evaluate the characteristics and outcomes of patients with ventilator-associated pneumonia (VAP) caused by Stenotrophomonas maltophilia (S. maltophilia), focusing on the impact of appropriate empirical antimicrobial treatment. Of the enrolled 240 patients with VAP due to S. maltophilia (median age: 45 years) in a tertiary-care hospital in southern Thailand between January 2010 and December 2021, 90% had medical comorbidities and 91% had previously received carbapenems. In addition, only 45% of the patients were initially admitted to the intensive care unit. Patients administered appropriate empirical antimicrobial treatment including colistin alone and colistin plus TMP-SMX or fluoroquinolone-based regimens had significantly lower 14-day, 30-day, and in-hospital mortalities, compared with those who did not receive appropriate empirical antimicrobial treatment (21% and 2% vs. 31%; 30% and 5% vs. 44%; and 30% and 12% vs. 53%, respectively). Thus, the use of appropriate empirical antimicrobial treatments led to a significantly reduced length of hospital stay, duration of ventilation, and hospital costs. The current study suggests that the use of appropriate empirical antimicrobial treatment based on susceptibility testing without considering pharmacokinetic properties and administration dosages improves the outcomes of patients with VAP due to S. maltophilia.

Abstract Purpose Stenotrophomonas maltophilia is a Gram-negative pathogen that most commonly causes hospital-acquired infections that can be extremely challenging to treat, contributing to underrecognized mortality throughout the world. The relative benefits of monotherapy as compared to combination therapy in patients diagnosed with S. maltophilia pneumonia, however, have yet to be established. Methods Data from 307 patients diagnosed with S. maltophilia hospital-acquired pneumonia (HAP) across four Chinese teaching hospitals from 2016 to 2022 were retrospectively analyzed. Results Of the analyzed patients, 55.7% (171/307) were administered combination definitive therapy, with a 30-day all-cause mortality rate of 41.0% (126/307). A propensity score weighting analysis revealed that compared with monotherapy, combination definitive therapy was associated with a comparable 30-day mortality risk in the overall patient cohort (OR 1.124, 95% CI 0.707–1.786, P = 0.622), immunocompetent patients (OR 1.349, 95% CI 0.712–2.554, P = 0.359), and patients with APACHE II scores

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Stenotrophomonas maltophilia, a non-fermentative, ubiquitous, gram-negative aerobic bacterium, is associated with high mortality rates, particularly in immunocompromised or debilitated patients. The prevalence rate of ICU-acquired pneumonia episodes caused by this microorganism has been found to be 2%. S. maltophilia has been identified as one of the top 10 microorganisms responsible for such infections in EU/EEA countries. This study describes an outbreak of S. maltophilia in an intensive care unit of a hospital in northern Italy. This includes an epidemiological investigation of the cases, the environmental microbiological controls carried out, a comparison of the strains by multilocus sequence typing (MLST), and the measures taken to prevent and control the outbreak. Among the seven clinical isolates of S. maltophilia analyzed herein, six demonstrated susceptibilities to trimethoprim–sulfamethoxazole. Conversely, one isolate of S. maltophilia exhibited resistance to first-line antibiotics. ST was found to be identical for six patients (ST 4), as well as in the environmental feedback on the trolley of Box 2. The analysis of the temporal and spatial progression of the outbreak has suggested that the transmission of S. maltophilia may have occurred through cross-transmission during care practices.

IntroductionAntimicrobial resistance is a growing problem that necessitates the development of new therapeutic options. Cefiderocol and aztreonam (AT) are often the last active β-lactams for treating metallo-β-lactamases (MBL)-producing Gram-negative bacilli. In these difficult-to-treat bacterial strains, AT resistance is frequently attributed to the co-occurrence of other resistance mechanisms. In the case of β-lactamases they can often be inhibited by avibactam. In the present study, we evaluated the use of the double-disc synergy test (DDST) as a screening tool for the detection of synergy between AT-avibactam (ATA). We validated both the Gradient Diffusion Strips (GDSs) superposition method and the commercially available Liofilchem’s ATA GDS.Materials and methodsWe tested AT susceptibility in combination with ceftazidime-avibactam for 65 strains, including 18 Serine-β-Lactamase (SBL)- and 24 MBL-producing Enterobacterales, 12 MBL-producing P. aeruginosa, and 11 S. maltophilia isolates. Interpretation was done with EUCAST breakpoints (version 13.0), AT breakpoints being used for ATA. The accuracy and validity of the GDSs superposition method and ATA GDS were evaluated using an AT GDS applied on Mueller Hinton Agar plates supplemented with avibactam (MH-AV). A DDST was performed to screen for synergy between antibiotic combinations.ResultsUsing MH-AV, all SBL- and MBL-positive Enterobacterales were susceptible or susceptible at increased exposure to the combination AT-avibactam. In contrast, only 2 out of the 12 (17%) P. aeruginosa strains and 9/11 (82%) of the S. maltophilia strains were susceptible- or susceptible at increased exposure for the combination of AT-avibactam. The DDST detected all synergies, demonstrating a 100% sensitivity and 100% negative predictive value for all bacterial strains.ConclusionThe DDST is a sensitive tool for screening for antibiotic synergy. Unlike S. maltophilia and SBL- and MBL-positive Enterobacterales, most MBL-positive P. aeruginosa strains remain resistant to AT-avibactam. ATA GDS should be preferred for MIC determination of the AT-avibactam combination, while the GDSs superposition method can be used as an alternative to the commercial test.

Purpose: Stenotrophomonas maltophilia is a Gram-negative pathogen that most commonly causes hospital-acquired infections that can be extremely challenging to treat, contributing to underrecognized mortality throughout the world. The relative benefits of monotherapy as compared to combination therapy in patients diagnosed with S. maltophilia pneumonia, however, have yet to be established. Methods: Data from 307 patients diagnosed with S. maltophilia hospital-acquired pneumonia (HAP) across four Chinese teaching hospitals from 2016 to 2022 were retrospectively analyzed. Results: Of the analyzed patients, 55.7% (171/307) were administered combination definitive therapy, with a 30-day all-cause mortality rate of 41.0% (126/307). A propensity score weighting analysis revealed that compared with monotherapy, combination definitive therapy was associated with a comparable 30-day mortality risk in the overall patient cohort (OR 1.124, 95% CI 0.707–1.786, P = 0.622), immunocompetent patients (OR 1.349, 95% CI 0.712–2.554, P = 0.359), and patients with APACHE II scores < 15 (OR 2.357, 95% CI 0.820–6.677, P = 0.111), whereas it was associated with a decreased risk of death in immunocompromised patients (OR 0.404, 95% CI.170–0.962, P = 0.041) and individuals with APACHE II scores ≥ 15 (OR 0.494, 95% CI 0.256–0.951, P = 0.035). Conclusion: The present data suggest that when treating S. maltophilia-HAP, immunocompromised patients and individuals with APACHE II scores ≥ 15 may potentially benefit from combination therapy. [ABSTRACT FROM AUTHOR]

Abstract Introduction We collected data on ventilator‐associated pneumonia (VAP) and hospital‐acquired pneumonia (HAP) induced by Stenotrophomonas maltophilia (SM) and Klebsiella pneumoniae (KP) and compared differences between two bacteria in mortality, duration of ventilator use, length of hospital stay, and risk factors for infection. Objectives This study aimed to evaluate the prognosis and to find risk factors of SM‐HAP/VAP versus KP‐HAP/VAP in the intensive care unit (ICU). Methods This retrospective cohort study included patients admitted to the ICU between June 2019 and June 2021 and diagnosed with SM‐HAP/VAP or KP‐HAP/VAP. The primary outcome was 28‐day mortality. Results Ninety‐two HAP/VAP patients (48 with SM‐HAP/VAP and 44 with KP‐HAP/VAP) were included. The 28‐day mortality was 16.7% (8/48 patients) in SM‐HAP/VAP and 15.9% (7/44 patients) in KP‐HAP/VAP (P = 0.922). After adjustment for potential confounders, the hazard ratios for 28‐day mortality in SM‐HAP/VAP were 1.3 (95% CI:0.5–3.7), 1.0 (95% CI:0.4–3.0), 1.4 (95% CI:0.5–4.0), and 1.1 (95% CI:0.4–3.4), respectively. Conclusion SM‐HAP/VAP and KP‐HAP/VAP patients in ICU might have a similar prognosis in mortality, the total duration of the artificial airway and ventilator use, the total length of ICU stay, and hospital stay. The risk factors of SM‐HAP/VAP versus KP‐HAP/VAP might be the artificial airway, ventilator use, gastric tube placement, acid suppressant and antibiotics (especially carbapenem).

Introduction: We collected data on ventilator‐associated pneumonia (VAP) and hospital‐acquired pneumonia (HAP) induced by Stenotrophomonas maltophilia (SM) and Klebsiella pneumoniae (KP) and compared differences between two bacteria in mortality, duration of ventilator use, length of hospital stay, and risk factors for infection. Objectives: This study aimed to evaluate the prognosis and to find risk factors of SM‐HAP/VAP versus KP‐HAP/VAP in the intensive care unit (ICU). Methods: This retrospective cohort study included patients admitted to the ICU between June 2019 and June 2021 and diagnosed with SM‐HAP/VAP or KP‐HAP/VAP. The primary outcome was 28‐day mortality. Results: Ninety‐two HAP/VAP patients (48 with SM‐HAP/VAP and 44 with KP‐HAP/VAP) were included. The 28‐day mortality was 16.7% (8/48 patients) in SM‐HAP/VAP and 15.9% (7/44 patients) in KP‐HAP/VAP (P = 0.922). After adjustment for potential confounders, the hazard ratios for 28‐day mortality in SM‐HAP/VAP were 1.3 (95% CI:0.5–3.7), 1.0 (95% CI:0.4–3.0), 1.4 (95% CI:0.5–4.0), and 1.1 (95% CI:0.4–3.4), respectively. Conclusion: SM‐HAP/VAP and KP‐HAP/VAP patients in ICU might have a similar prognosis in mortality, the total duration of the artificial airway and ventilator use, the total length of ICU stay, and hospital stay. The risk factors of SM‐HAP/VAP versus KP‐HAP/VAP might be the artificial airway, ventilator use, gastric tube placement, acid suppressant and antibiotics (especially carbapenem). [ABSTRACT FROM AUTHOR]

Green synthesis of metal nanoparticles is gathering attention due to eco-friendly processing. Tungsten oxide (WO3) nanoparticles have immense applications as semiconductors, antimicrobials and photo thermal materials but their synthesis using biological systems is hitherto unpublicized. The paper discusses synthesis of WO3 nanoparticles using Stenotrophomonas maltophilia and the optimization of physico-chemical parameters of incubation which influence the growth and metabolism of the bacterium and consequently the size of the WO3 nanoparticles. The biogenic synthesis of WO3 nanoparticles was confirmed by ATR-FTIR and X-ray diffraction analysis. Taguchi and analysis of variance method was applied to optimize the physico-chemical parameters (pH, temperature, time, aeration rate and concentration), considering particle size and poly dispersity index (PDI) of the nanoparticles as the experimental responses. Under the design of experiments technique, Taguchi's L27 array was selected to determine the optimal process parameters which could significantly reduce the particle size and PDI of WO3 nanoparticles. Statistical analysis by signal-to-noise ratio, regression analysis and ANOVA (95% confidence level) on experimental responses confirmed pH and aeration as most influential while temperature and time as least influential parameters. pH 8, Temperature 40 °C, aeration 200 RPM, time 3 days and concentration of sodium tungstate at 1 mM (p3t3r3d3c1) was the most effective level and parameters combination for smallest particle size and PDI of WO3 nanoparticles. Regression models developed for particle size and PDI exhibited a linear regression of 97.80% and 90.89% respectively, while the confirmation test validated the size and PDI of the experimental values against predicted results. SEM image of WO3 nanoparticles illustrated the same particle size as that predicted, further validating the model. The study can be applied to optimize any process parameters in the industry or on biological systems.

We investigated the in vitro susceptibility of ceftazidime-avibactam (CZA) resistant Stenotrophomonas maltophilia to the associations aztreonam/amoxicillin-clavulanate (ATM-AMC) and ATM-CZA. Forty clinical isolates of S. maltophilia recovered from sputum samples of 40 cystic fibrosis people were selected from the collection of the Nantes University Hospital, based on their resistance to CZA. Minimum inhibitory concentrations (MICs) of ATM-CZA and ATM-AMC were determined for each isolate by an Etest strip superposition method, and by Etest for each individual antibiotic. MICs of CZA, ATM, and AMC ranged from 12 to ≥256, ≥256, and 16 to ≥256 mg/L, respectively. Synergistic effects were observed with the ATM-CZA combination for all isolates (fractional inhibitory concentration index range of 0.01 to 0.27), with combination MICs ranging from 0.75 to 16 mg/L (MIC50/90 = 3/12 mg/L), corresponding to a decrease of at least 16-folds in the MIC of ATM. In 23 (57.5%) S. maltophilia isolates, the association of AMC to ATM was also synergistic and combination MICs were ≤16 mg/L (EUCAST breakpoint for ATM resistance in Pseudomonas aeruginosa). Our results show that ATM-CZA or ATM-AMC could be alternative therapeutic options against some highly resistant S. maltophilia. This encourages further experimental studies, in particular time-kill analyses, and clinical trials to delineate conditions required for use of these combinations in practice. [ABSTRACT FROM AUTHOR]

Abstract Background The release of triphenylmethane dyes, like malachite green (MG) and crystal violet (CV), into the environment is a cause of concern due to its toxicity, mutagenicity and carcinogenicity. Result A bacterial strain that is capable of decolorizing both dyes was isolated from the composted neem oil-seed cake. The strain was characterized as Stenotrophomonas maltophilia based on the 16S rRNA gene sequence and designated as isolate TPMD-1. The kinetic study of the dye degradation revealed the efficiency of the above isolate to degrade MG. The effect of substrate concentration, pH, temperature, and agitation on the decolorization of MG by the isolate was also studied. The MG degradation rate was slightly more in neutral pH at 28–30 °C and 150 rpm. The UV-spectroscopy, HPLC, and FTIR analyses of the dye sample before and after bacterial treatment revealed the high ability of S. maltophilia TPDM-1 in the removal of MG from the media. The genetic snapshot of the isolate by PCR amplification and sequencing showed the presence of genes 'lac’ and ‘tmr’ that codes for laccase and triphenylmethane reductase. Conclusion This study presented the first report of Stenotrophomonas maltophilia in the degradation and detoxification of MG dye by oxidoreduction, which could be used for the bioremediation of aquatic environments contaminated by MG.

Introduction: Stenotrophomonas maltophilia, a non-fermentative bacterium, predominantly causes opportunistic infections in immunocompromised individuals and those receiving long-term, large-dose, broad spectrum antimicrobial agents. It is inherently resistant to most of the available antimicrobial agents. Trimethoprim-sulfamethoxazole (TMP/SMX), ceftazidime (CAZ), and levofloxacin (LVX) are the drugs of choice used for the infection treatment. The study aims to investigate the presence of plasmid-mediated quinolone resistance determinants of QnrA, QnrB, QnrC, QnrD, QnrS, and OqxAB genes in S. maltophilia isolates. Materials and Methods: A total of 122 S. maltophilia isolates from various clinical specimens were tested in the study. The susceptibility of TMP/SMX and LVX was determined by disk diffusion method. The minimum inhibitory concentration value of CAZ was determined by the gradient diffusion test. Qnr (A, B, C, S, D) determinants and OqxAB were investigated using multiplex polymerase chain reaction. OqxA was investigated in the isolates and the presence of OqxB in OqxA-positive isolates. Results: Five (4%) of the S. maltophilia isolates were resistant to TMP/SMX. Levofloxacin and CAZ resistances were determined as 6.5% and 56.5%, respectively. QnrS was detected in two of the isolates, and OqxA gene was found in three isolates. However, these isolates were not OqxB positive. One of these three positive isolates has been previously found to be QnrS-positive. Conclusion: In our study, QnrS was detected in two and OqxA gene in three of the S. maltophilia isolates.

Stenotrophomonas maltophilia has emerged as an important opportunistic pathogen, causing infections whose management is often problematic due to its inherent resistance to many antibiotics. In this study, we aimed to investigate the antimicrobial susceptibility of colistin and tygecyclin as an alternative treatment options for S. maltophilia infections. A total of 122 S. maltophilia isolates were tested. Minimum inhibitory concentration (MIC) values of colistin and tygecycline were determined by broth microdilution method. Susceptibility of TMP/SMX and levofloxacin (LVX) were determined by disc diffusion method and MIC value of ceftazidime (CAZ) was determined by using E-test. Out of 122 S. maltophilia isolates, 5 (4%) of them were resistant to TMP-SXM. MIC range was 0.125- >512 µg/ml and MIC50 64 µg/ml, MIC90 512 µg/ml for colistin. MIC range for tygecyclin was detected as 0.5- >8, MIC50 2 µg/ml and MIC90 8 µg/ml. Tygecyclin resistance was detected as 66.4% according to the EUCAST guideline and 13.1% according to the USA-FDA breakpoints. And colistin resistance was determined as 86.9% according to both guidelines. [ABSTRACT FROM AUTHOR]

Cigarette smoke (CS), the main source of indoor air pollution and the primary risk factor for respiratory diseases, contains chemicals that can perturb microbiota through antibiotic effects. Although smoking induces a disturbance of microbiota in the lower respiratory tract, whether and how it contributes to initiation or promotion of emphysema are not well clarified. Here, we demonstrated an aberrant microbiome in lung tissue of patients with smoking-related COPD. We found that Stenotrophomonas maltophilia (S. maltophilia) was expanded in lung tissue of patients with smoking-related COPD. We revealed that S. maltophilia drives PANoptosis in alveolar epithelial cells and represses formation of alveolar organoids through IRF1 (interferon regulatory factor 1). Mechanistically, IRF1 accelerated transcription of ZBP1 (Z-DNA Binding Protein 1) in S. maltophilia -infected alveolar epithelial cells. Elevated ZBP1 served as a component of the PANoptosome, which triggered PANoptosis in these cells. By using of alveolar organoids infected by S. maltophilia , we found that targeting of IRF1 mitigated S. maltophilia -induced injury of these organoids. Moreover, the expansion of S. maltophilia and the expression of IRF1 negatively correlated with the progression of emphysema. Thus, the present study provides insights into the mechanism of lung dysbiosis in smoking-related COPD, and presents a potential target for mitigation of COPD progression. For alveolar epithelial cells, Stenotrophomonas maltophilia , via activating IRF1, accelerates ZBP1 transcription. Overexpression of ZBP1 contributes to formation of PANoptosomes and triggers PANoptosis, which facilitates the progression of emphysema. [Display omitted] • 16S rRNA-seq analysis identified an abnormal expansion of S. maltophilia in lung tissue of smoking-related COPD. • S. maltophilia infection represses alveolar organoid formation. • In alveolar epithelial cells, S. maltophilia drives PANoptosis via activation of the IRF1/ZBP1 axis. • S. maltophilia is a specific and sensitive biomarker of smoking-related COPD. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia has been demonstrated herein to reduce CO 2 without any cofactor, photon or hydrogen (H 2) addition during reaction. S. maltophilia reduces 13CO 2 into 13C-labeled formate in batch mode. Two intracellular enzymes are curently being considered for their ability to catalyze the CO 2 reduction reaction: a Fe-nitrogenase and a formate dehydrogenase (FeS-FDH). The reaction was intensified by implementing the bacteria in an electrolysis cell continuously fed with CO 2. In this configuration, CO 2 removal reached up to 25% v/v at 30°C and atmospheric pressure. [Display omitted] • An isolated S. maltophilia bacterium was demonstrated to reduce CO 2 without H 2. • A commercial strain whose genome matches at 99.9% has similar CO 2 -reducing activity. • Fed-batch electrolysis allowed increasing CO 2 removals by at least 20-times. • The strain was active for at least 46 days and CO 2 removals up to 25% v/v were got. • The bacterial strain S. maltophilia was also demonstrated to reduce N 2. [ABSTRACT FROM AUTHOR]

This study describes a novel transposable bacteriophage, ø SHP3, continuously released by Stenotrophomonas maltophilia strain c31. Morphological observation and genomic analysis revealed that ø SHP3 is a siphovirus with a 37,611-bp genome that encodes 51 putative proteins. Genomic comparisons indicated that ø SHP3 is a B3-like transposable phage. Its genome configuration is similar to that of Pseudomonas phage B3, except for the DNA modification module. Similar to B3-like phages, the putative transposase B of ø SHP3 is a homolog of the type two secretion component ExeA, which is proposed to serve as a potential virulence factor. Moreover, most proteins of ø SHP3 have homologs in transposable phages, but only ø SHP3 carries an RdgC-like protein encoded by gene 3, which exhibits exonuclease activity in vitro. Two genes and their promoters coding for ø SHP3 regulatory proteins were identified and appear to control the lytic-lysogenic switch. One of the proteins represses one promoter activity and confers immunity to ø SHP3 superinfection in vivo. The short regulatory region, in addition to the canonical bacterial promoter sequences, displays one LexA and two CpxR recognition sequences. This suggests that LexA and the CpxR/CpxA two-component system might be involved in the control of the ø SHP3 genetic switch. [ABSTRACT FROM AUTHOR]

Background: The release of triphenylmethane dyes, like malachite green (MG) and crystal violet (CV), into the environment is a cause of concern due to its toxicity, mutagenicity and carcinogenicity. Result: A bacterial strain that is capable of decolorizing both dyes was isolated from the composted neem oil-seed cake. The strain was characterized as Stenotrophomonas maltophilia based on the 16S rRNA gene sequence and designated as isolate TPMD-1. The kinetic study of the dye degradation revealed the efficiency of the above isolate to degrade MG. The effect of substrate concentration, pH, temperature, and agitation on the decolorization of MG by the isolate was also studied. The MG degradation rate was slightly more in neutral pH at 28–30 °C and 150 rpm. The UV-spectroscopy, HPLC, and FTIR analyses of the dye sample before and after bacterial treatment revealed the high ability of S. maltophilia TPDM-1 in the removal of MG from the media. The genetic snapshot of the isolate by PCR amplification and sequencing showed the presence of genes 'lac' and 'tmr' that codes for laccase and triphenylmethane reductase. Conclusion: This study presented the first report of Stenotrophomonas maltophilia in the degradation and detoxification of MG dye by oxidoreduction, which could be used for the bioremediation of aquatic environments contaminated by MG. [ABSTRACT FROM AUTHOR]

Objective: Stenotrophomonas maltophilia is commonly a nosocomial pathogen with multiple drug resistance, although it has been reported in communityacquired infections. Trimethoprim-sulfamethoxazole is prefered as the first antibiotic in the treatment of S. maltophilia infections. In hospitalized patients, the respiratory tract is the body area that it is most frequently isolated. Although it is known about the bacteria that it causes the formation of biofilms due to its ability to attach to plastic surfaces, relatively little is known in terms of virulence factors. The aim of our study is to compare the property of biofilm formation of pulmonary and extrapulmonary isolates of S. maltophilia. Methods: A total of 78 S. maltophilia isolates isolated from 37 pulmonary and 41 extrapulmonary specimens were included in the study. The identfication of the isolates were performed in Vitek MS (bioMérieux, Fransa) automated system. In addition, antibiotic susceptibility was tested using the disc diffusion method. All isolates were investigated for biofilm formation by microtitration plate method. The relation of the pulmonary or extrapulmonary specimens with the biofilm formation was statistically investigated. Results: All of the isolates were found susceptible to trimetoprim-sulphametaxozole. Biofilm formation was detected in 68 of 78 (87.2%) S. maltophilia isolates. Biofilm formation of S. maltophilia isolates that isolated from pulmonary and extrapulmonary specimens were detected as 35/37 (94.6%), 33/41 (80.5%), respectively. There was no statistical relationship between pulmonary or extrapulmonary samples and biofilm forming capability. Conclusion: It was observed that a significant part (87.2%) of all strains included in the study were formed biofilms. It was seen that the biofilm activity of the pulmonary specimens was proportionally higher than extrapulmonary specimens. However, there was no significant difference in terms of biofilm formation between the strains isolated from pulmonary and extrapulmonary specimens. It was also detected that there was no development of resistance to trimethoprimsulfamethoxazole. New comprehensive studies on this subject may contribute to a better understanding of the virulence mechanisms of S. maltophilia. [ABSTRACT FROM AUTHOR]

Background: Stenotrophomonas maltophilia is associated with respiratory tract infections in immunocompromised patients, and it has emerged as an important nosocomial pathogen, with admission to intensive care units (ICUs) and ventilators as recognized risk factors. Aim: To describe the investigation of a sudden increase in patients with pneumonia caused by S. maltophilia at a Swedish ICU and the control measures taken. Methods: Lower respiratory tract cultures from patients admitted to the ICU were obtained, and environmental cultures were collected from sink drains and medical equipment. Isolates identified as S. maltophilia were subjected to antibiotic susceptibility testing and whole genome sequencing (WGS). Findings: A total of 17 S. maltophilia isolates were found (four from patients and 13 from the environment). The WGS identified two outbreak clones, sequence type (ST) 361 and ST138, and seven unique ones. Most likely, the outbreak clones originated from two sinks, and transmission was enhanced by a calorimeter. After changing the sink and calorimeter routines, no more cases were registered. Conclusion: Acquisition of S. maltophilia from the hospital environment appears to be easy, especially if water is involved. To control this bacterium, better knowledge of its transmission routes in hospital environments is required.

Stenotrophomonas maltophilia, an emerging opportunistic pathogen, is widely distributed in the environment the resistance mechanisms, and virulence factors of this bacterium facilitate its dissemination in hospitals. This study aimed to characterize the molecular epidemiology of S. maltophilia strains associated with an outbreak in the Children's Hospital of México Federico Gómez (HIMFG). Twenty-one clinical S. maltophilia strains were recovered from cultures of blood and urine samples from 10 pediatric patients at the emergency department, and nine environmental S. maltophilia strains recovered from faucets in the same area were also included. Two of the 10 patients were related with health care-associated infections (HCAIs), and the other eight patients (8/10) were infected with environmental S. maltophilia strains. The outbreak was controlled by monthly disinfection of the faucets in the emergency department. Typing using pulsed-field gel electrophoresis (PFGE) showed a 52% genetic diversity with seven pulsotypes denoted P1–P7 among all S. maltophilia strains. Three pulsotypes (P2, P3, and P7) were identified among both the clinical and environmental S. maltophilia strains and associated with two type sequences (STs), namely, ST304 and ST24. Moreover, 80% (24/30) of the strains exhibited resistance mainly to tetracycline, 76.66% (23/30) to trimethoprim-sulfamethoxazole, and 23.33% (7/30) to the extended-spectrum β-lactamase (ESBL) phenotype. The main resistance genes identified by multiplex PCR were sul1 in 100% (30/30), qnr in 86.66% (26/30), and intl1 in 80% (24/30) of the samples, respectively. Furthermore, the pilU, hlylII, and rmlA genes were identified in 96.6% (29/30), 90% (27/30), and 83.33% (25/30) of the samples, respectively. Additionally, 76.66% (23/30) of the S. maltophilia strains exhibited high swimming motility, 46.66% (14/30) showed moderate biofilm formation capacity, 43.33% (13/30) displayed moderate twitching motility, and 20% (6/30) exhibited high adherence. The clinical S. maltophilia strains isolated from blood most strongly adhered to HTB-9 cells. In conclusion, the molecular epidemiology and some of the features such as resistance, and virulence genes associated with colonization patterns are pathogenic attributes that can promote S. maltophilia dissemination, persistence, and facilitate the outbreak that occurred in the HIMFG. This study supports the need for faucet disinfection as a control strategy for clinical outbreaks.

Stenotrophomonas maltophilia , an emerging opportunistic pathogen, is widely distributed in the environment the resistance mechanisms, and virulence factors of this bacterium facilitate its dissemination in hospitals. This study aimed to characterize the molecular epidemiology of S. maltophilia strains associated with an outbreak in the Children's Hospital of México Federico Gómez (HIMFG). Twenty-one clinical S. maltophilia strains were recovered from cultures of blood and urine samples from 10 pediatric patients at the emergency department, and nine environmental S. maltophilia strains recovered from faucets in the same area were also included. Two of the 10 patients were related with health care-associated infections (HCAIs), and the other eight patients (8/10) were infected with environmental S. maltophilia strains. The outbreak was controlled by monthly disinfection of the faucets in the emergency department. Typing using pulsed-field gel electrophoresis (PFGE) showed a 52% genetic diversity with seven pulsotypes denoted P1–P7 among all S. maltophilia strains. Three pulsotypes (P2, P3, and P7) were identified among both the clinical and environmental S. maltophilia strains and associated with two type sequences (STs), namely, ST304 and ST24. Moreover, 80% (24/30) of the strains exhibited resistance mainly to tetracycline, 76.66% (23/30) to trimethoprim-sulfamethoxazole, and 23.33% (7/30) to the extended-spectrum β-lactamase (ESBL) phenotype. The main resistance genes identified by multiplex PCR were sul1 in 100% (30/30), qnr in 86.66% (26/30), and intl1 in 80% (24/30) of the samples, respectively. Furthermore, the pilU, hlylII , and rmlA genes were identified in 96.6% (29/30), 90% (27/30), and 83.33% (25/30) of the samples, respectively. Additionally, 76.66% (23/30) of the S. maltophilia strains exhibited high swimming motility, 46.66% (14/30) showed moderate biofilm formation capacity, 43.33% (13/30) displayed moderate twitching motility, and 20% (6/30) exhibited high adherence. The clinical S. maltophilia strains isolated from blood most strongly adhered to HTB-9 cells. In conclusion, the molecular epidemiology and some of the features such as resistance, and virulence genes associated with colonization patterns are pathogenic attributes that can promote S. maltophilia dissemination, persistence, and facilitate the outbreak that occurred in the HIMFG. This study supports the need for faucet disinfection as a control strategy for clinical outbreaks. [ABSTRACT FROM AUTHOR]

Infections caused by Stenotrophomonas maltophilia may be fatal in diseases such as leukaemia which causes immunodeficiency. Herein, we report a rare case of 8-year-old girl with acute lymphoblastic leukaemia, who developed perianal cellulitis and pneumonia secondary to S. maltophilia bacteraemia while undergoing broad spectrum antimicrobial agents for neutropenic fever.

The health of the plant and soil fertility is dependent on the plant–microbes interaction in the rhizosphere. Microbial life tends to endure various rhizosphere plant–microbe interactions. Phytohormones such as auxins, cytokinins, gibberellic acid, ethylene and abscisic acid are termed as the classical group of hormones. Out of the 70 rhizobacterial strains isolated from the Coleus rhizosphere, three different rhizobacterial strains Pseudomonas stutzeri MTP40, Stenotrophomonas maltophilia MTP42 and Pseudomonas putida MTP50 having plant growth-promoting attributes were isolated and characterized for its phytohormone-producing ability. The phytohormones such as indole 3-acetic acid (IAA), gibberellic acid and cytokinin (kinetin and 6-benzyladenosine) were affirmed in culture supernatant of the above isolates. IAA was detected in all the three isolates, where in highest production was found in S. maltophilia MTP42 (240 µg/mL) followed by P. stutzeri MTP40 (250 µg/mL) and P. putida MTP50 (233 µg/mL). Gibberellic acid production was found maximum in MTP40 (34 µg/mL), followed by MTP42 (31 µg/mL) and MTP50 (27 µg/mL). The cytokinin production from the isolates, namely, MTP40, MTP42 and MTP50 were 13, 11 and 7.5 µg/mL, respectively. The isolates showing the production of plant growth enhancing phytohormones can be commercialized as potent bioformulations.

Aerobic, non-fermentative and Gram-negative Stenotrophomonas maltophilia is a multidrug-resistant bacilli that is known to be pathogen for human and animals. S. maltophilia has been isolated from different animal species and also found in a variety of environments including soil, water, and plants. S. maltophilia, which has the ability to form biofilms on surfaces that cause environmental problems, is resistant to many antibiotic classes such as cephalosporins, carbapenems, and aminoglycosides. Here in this study, its aimed to determine the inhibition activities of natural phenolic compounds eugenol and pulegone against S. maltophilia MU69. Antibacterial activities of eugenol and pulegone were initially determined by disc diffusion method. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were also determined by tube dilution assay. Antibiofilm activities of the compounds were investigated by crystal violet staining and also monitorized using Scanning Electron Microscopy (SEM). Zone of inhibition measurements were found to be 39 mm and 28 mm for eugenol and pulegone, respectively. MIC and MBC values were found to be 3.12 mg/mL for eugenol while these were 2.5 mg/mL and 5 mg/mL for pulegone, respectively. The highest antibiofilm activity was found to be 56.30±0.45% for MIC of eugenol. To our knowledge, this is the first report of the antibacterial and antibiofilm activity of eugenol and pulegone against S. maltophilia. According to the biological activity results, it can be concluded that these natural agents may be potentially used for veterinary sciences, food industry or pharmaceutical applications that aim to manage S. maltophilia biofilm. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia is a multi-drug-resistant global opportunistic nosocomial pathogen, which possesses a huge number of virulence factors and antibiotics resistance characteristics. Iron has a crucial contribution toward growth and development, cell growth and proliferation, and pathogenicity. The bacterium found to acquire iron for its cellular process through the expression of two iron acquisition systems. Two distinct pathways for iron acquisition are encoded by the S. maltophilia genome-a siderophore-and heme-mediated iron uptake system. The entAFDBEC operon directs the production of the enterobactin siderophore of catecholate in nature, while heme uptake relies on hgbBC and potentially hmuRSTUV operon. Fur and sigma factors are regulators of S. maltophilia under iron-limited condition. Iron potentially act as a signal which plays an important role in biofilm formation, extracellular polymeric substances (EPS), extracellular enzymes production, oxidative stress response, diffusible signal factor (DSF) and siderophore production in S. maltophilia. This review summarizes the current knowledge of iron acquisition in S. maltophilia and the critical role of iron in relation to its pathogenicity.

Objectives: Stenotrophomonas maltophilia (S. maltophilia), an opportunistic pathogen, causes infection in patients undergoing immunosuppressive therapy, mechanical ventilation, or catheters and in long-term hospitalized patients. Due to its extensive resistance to various antibiotics and chemotherapeutic agents, S. maltophilia is challenging to treat. Using case reports, case series, and prevalence studies, the current study provides a systematic review and meta-analysis of antibiotic resistance profiles across clinical isolates of S. maltophilia., Methods: A systematic literature search was performed for original research articles published in Medline, Web of Science, and Embase databases from 2000 to 2022. Statistical analysis was performed using STATA 14 software to report antibiotic resistance of S. maltophilia clinical isolates worldwide., Results: 223 studies (39 case reports/case series and 184 prevalence studies) were collected for analysis. A meta-analysis of prevalence studies demonstrated that the most antibiotic resistance worldwide was to levofloxacin, trimethoprim-sulfamethoxazole (TMP/SMX), and minocycline (14.4%, 9.2%, and 1.4%, respectively). Resistance to TMP/SMX (36.84%), levofloxacin (19.29%), and minocycline (1.75%) were the most prevalent antibiotic resistance types found in evaluated case reports/case series studies. The highest resistance rate to TMP/SMX was reported in Asia (19.29%), Europe (10.52%), and America (7.01%), respectively., Conclusion: Considering the high resistance to TMP/SMX, more attention should be paid to patients' drug regimens to prevent the emergence of multidrug-resistant S. maltophilia isolates., Competing Interests: Competing interests None declared., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Stenotrophomonas maltophilia is a multi-drug-resistant global opportunistic nosocomial pathogen, which possesses a huge number of virulence factors and antibiotics resistance characteristics. Iron has a crucial contribution toward growth and development, cell growth and proliferation, and pathogenicity. The bacterium found to acquire iron for its cellular process through the expression of two iron acquisition systems. Two distinct pathways for iron acquisition are encoded by the S. maltophilia genome-a siderophore-and heme-mediated iron uptake system. The entAFDBEC operon directs the production of the enterobactin siderophore of catecholate in nature, while heme uptake relies on hgbBC and potentially hmuRSTUV operon. Fur and sigma factors are regulators of S. maltophilia under iron-limited condition. Iron potentially act as a signal which plays an important role in biofilm formation, extracellular polymeric substances (EPS), extracellular enzymes production, oxidative stress response, diffusible signal factor (DSF) and siderophore production in S. maltophilia. This review summarizes the current knowledge of iron acquisition in S. maltophilia and the critical role of iron in relation to its pathogenicity. [ABSTRACT FROM AUTHOR]

Endosulfan is one of the persistent organochlorinated pesticides used extensively throughout the world, particularly in the developing countries. Its microbial metabolic transformation product endosulfan sulphate is more toxic and persistent than the parent compound itself. In order to completely mineralize endosulfan, augmentation of soil microbial community with efficient endosulfan degradation properties could a potentially viable option. In the present study, endosulfan degrading bacterium was isolated from the agriculture-contaminated soil of Shujaabad, Multan, Pakistan by using enrichment technique. The isolated bacterial strain EN-1 (Endosulfan-1) was identified as S. maltophilia by 16S rRNA sequencing and biochemical analysis. EN-1 has demonstrated the ability to utilize endosulfan as sole sulfur source. Kinetics of endosulfan degradation was studied at various initial concentrations ranges from 5 mg/L to 100 mg/L by growth dependent and growth independent kinetic models. Biodegradation kinetics revealed that the bacterium was highly efficient in endosulfan degradation. The average values of kinetic constants i.e. Ks, and µmax were 13.73 mg/L and 0.210 h−1 respectively, while µmax/Ks ratio was 0.015. Addition of sulfur decreased the rate of degradation as the µmax/Ks was observed to reduce. GC-MS analysis revealed that the bacterium metabolised the endosulfan into non-toxic metabolite i.e. endosulfan diol. The study instigates a complete elucidation of degradation process for commercial applications. [ABSTRACT FROM AUTHOR]

Poultry industry produces a vast amount of feather waste annually, which forms a burden for environment protection. However, feathers are valuable bio-resources with high keratinaceous protein content and can be converted into more valuable materials through some approaches such as biodegradation by microorganism-derived keratinases. The characters of keratinases in microorganisms remain largely undetermined. In this study, it is reported that the morphological change of cell surface and the activities of intracellular and extracellular keratinases in Stenotrophomonas maltophilia (S. maltophilia) DHHJ. S. maltophilia DHHJ was cultured on lysogeny broth (LB) and feather broth (FB) through fermenter technology, and ultrastructure of cell and keratinase activity including extracellular and intracellular enzyme were observed respectively. Ultrastructural change on the cell surface was only observed for the bacteria cultured on FB medium, but not on LB, suggesting that the change could be induced by feather keratin. Therefore, the results showed that extracellular keratinase is a kind of induction enzyme while intracellular keratinase is a kind of constitute enzyme in 5. maltophilia DHHJ. [ABSTRACT FROM AUTHOR]

Bacterial strain 4B4 capable of degrading microcystin-LR (MC-LR) was isolated from the Beira Lake (N 6° 55' 46'', E 79° 51' 15'') in Sri Lanka. Based on phylogenetic analysis of the 16S rRNA gene sequence, the isolate 4B4 was identified as Stenotrophomonas maltophilia. The bacterium showed 100 % removal of MC-LR in 10 and 8 days of incubation at 28 °C and 32 °C, respectively. Optimisation studies confirmed that the addition of nitrates (0.4 ppm) and phosphates (0.02 ppm) to the medium can increase the microcystin removal rate of the bacterial strain. Further evaluation of S. maltophilia revealed that it is capable of degrading other microcystin analogues; microcystin-RR, -LW, -LF and nodularin (NOD) as well. [ABSTRACT FROM AUTHOR]

Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR)2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli. [ABSTRACT FROM AUTHOR]

The health of the plant and soil fertility is dependent on the plant–microbes interaction in the rhizosphere. Microbial life tends to endure various rhizosphere plant–microbe interactions. Phytohormones such as auxins, cytokinins, gibberellic acid, ethylene and abscisic acid are termed as the classical group of hormones. Out of the 70 rhizobacterial strains isolated from theColeusrhizosphere, three different rhizobacterial strainsPseudomonas stutzeriMTP40,Stenotrophomonas maltophiliaMTP42 andPseudomonas putidaMTP50 having plant growth-promoting attributes were isolated and characterized for its phytohormone-producing ability. The phytohormones such as indole 3-acetic acid (IAA), gibberellic acid and cytokinin (kinetin and 6-benzyladenosine) were affirmed in culture supernatant of the above isolates. IAA was detected in all the three isolates, where in highest production was found inS. maltophiliaMTP42 (240 µg/mL) followed byP. stutzeriMTP40 (250 µg/mL) andP. putidaMTP50 (233 µg/mL). Gibberellic acid production was found maximum in MTP40 (34 µg/mL), followed by MTP42 (31 µg/mL) and MTP50 (27 µg/mL). The cytokinin production from the isolates, namely, MTP40, MTP42 and MTP50 were 13, 11 and 7.5 µg/mL, respectively. The isolates showing the production of plant growth enhancing phytohormones can be commercialized as potent bioformulations. [ABSTRACT FROM PUBLISHER]

Background: Nonfermenting gram-negative bacilli have emerged as important healthcare-associated pathogens. It is important to correctly identify all clinically significant nonfermenting gram-negative bacilli considering the intrinsic multidrug resistance exhibited by these bacteria. Materials and Methods: A retrospective study was undertaken to identify the various nonfermenting gram-negative bacilli other than Pseudomonas aeruginosa and Acinetobacter spp. isolated from respiratory samples (n = 9363), to understand their clinical relevance and to analyze their antibiotic susceptibility pattern. Results: Nonfermenting gram-negative bacilli were isolated from 830 (16.4%) samples showing significant growth. Thirty-three (4%) isolates constituted nonfermenting gram-negative bacilli other than P. aeruginosa and Acinetobacter spp. Stenotrophomonas maltophilia (15, 45.5%) was the most common isolate followed by Burkholderia cepacia (4, 12.1%), Sphingomonas paucimobilis (3, 9.1%), and Achromobacter xylosoxidans (3, 9.1%). On the basis of clinicomicrobiological correlation, pathogenicity was observed in 69.7% (n = 23) isolates. Timely and correct treatment resulted in clinical improvement in 87.9% cases. Conclusion: Any nonfermenting gram-negative bacilli isolated from respiratory tract infection should not be ignored as mere contaminant, but correlated clinically for its pathogenic potential and identified using standard methods so as to institute appropriate and timely antibiotic coverage.

Aims: The presents study examines the purification and characterization of a chitinase from S. maltophilia SJ602 strainisolated from a soil sample collected from Jamia Hamdard, New Delhi.Methodology and Results: The purification steps included chitin affinity using colloidal chitin as the affinity matrix andcolumn chromatography using Sephadex G-100. The chitinase was purified to 66 fold having a yield of 17%. The molecular weight of the chitinase was found to be around 29 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The pH and temperature optima of the purified chitinase were found to be at pH 5.5 and60 °C, respectively. Conclusion, Significance and Impact of the study: Besides showing a significant yield, the enzyme has a highthermal stability which has its applicability in the recycling of chitin waste.

Stenotrophomonas maltophilia is a multidrug-resistant nosocomial pathogen that is difficult to identify by using current methods. This study aimed to detect S. maltophilia in raw milk and some dairy products. A total of 90 raw milk samples including dairy farms, dairy shops and street vendors (30 samples each) were examined. Also, 60 cheese samples (30 Damietta cheese and 30 Kareish cheese), 30 cream and 30 cooking butter samples were examined. Results showed that 25 and 14 Stenotrophomonas isolates were recovered from milk and some milk products samples and identified as S. maltophilia by biochemical tests and PCR assay, respectively. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia is known for nosocomial habitat. Infective endocarditis due to this organism is rare and challenging because of resistance to multiple broad-spectrum antibiotic regimens. Early detection and appropriate antibiotic based on culture sensitivity reports are the key to its management. We report the diagnosis, treatment, and outcome of two cases of infective endocarditis caused by S. maltophilia.

Background : Stenotrophomonas maltophilia, previously named as Pseudomonas or Xanthomonas maltophilia, is an important nosocomial pathogen . Aim : The purpose of the present study was to investigate the prevalence of S. maltophilia in Iranian hospitals and its susceptibility to available antimicrobial agents. Setting and design: A cross-sectional study in Imam Khomeini Hospital affiliated to Tehran University of Medical Sciences. Materials and Methods : All blood specimens were sent to the laboratory for blood culture and biochemical analysis. One hundred samples were positive for S. maltophilia. We used disk diffusion and E-test in order to determine minimal inhibitory concentration (MIC) of ceftazidime and co-trimoxazole as the first line antibiotics for S. maltophilia. The tests were performed and interpreted according to the guidelines of Clinical Laboratory Standards Institute (CLSI). Statistical analysis: Chi-square test and Kappa measurement of agreement were applied as appropriate. Results : S. maltophilia was the most frequent pathogen (895 specimens; 38.9%) isolated from the samples which were mostly from emergency ward (780 specimens; 33.9%). Ceftazidime MIC 50 and MIC 90 were 2 and 32 μg/ml, respectively (sensitive ≤8 μg/ml and resistant ≥32 μg/ml according to CLSI guideline). MIC 50 and MIC 90 for co-trimoxazole were 0.5 and 2 μg/ml, respectively (sensitive ≤2 μg/ml and resistant ≥4 μg/ml according to CLSI guideline). Conclusion : S. maltophilia is the most frequent pathogen in our hospital with a high susceptibility to both ceftazidime and co-trimoxazole.