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Indian Journal of Medical Microbiology Jun 2024Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen that can cause many community and hospital-acquired infections. This study was conducted to...
BACKGROUND
Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen that can cause many community and hospital-acquired infections. This study was conducted to investigate the SCCmec gene types responsible for methicillin resistance in MRSA isolates isolated from hospitalised patients.
MATERIAL AND METHODS
MRSA isolates isolated from samples sent from various clinics to Gaziantep University Hospital Microbiology Laboratory between March 2021-January 2022 were included in the study. Bacteria were identified using by VITEK 2 automated system. Cefoxitin (FOX) resistance was determined by the disc diffusion method according to EUCAST standards. Cefoxitin resistance was confirmed by the Penicillin Binding Protein 2' latex agglutination test. Types of mecA, mecC, coa, nuc, Panton Valentin Leukocidin (PVL), ccrC2, class A mec, SCCmec types in isolates detected as MRSA were investigated by real-time PCR.
RESULTS
In this study, 116 isolates meeting the study criteria were examined. By detecting the nuc and coa genes in all isolates by PCR, the phenotypic identification of S.aureus was confirmed. While the mecA gene was detected in all MRSA isolates, no mecC gene was detected in any isolates. Detected SCCmec types were as follows; SCCmec Type 1 (2.6%), Type II (28.4%), Type III (12.9%), Type IVa (11.2%), Type IVb (3.4%), Type IVc (3.4%), Type IVg (12.1%), Type V (0.9%), Type VII (4.3%), Type VIII (18.1%), Type IX (0.9%), Type XII (1.7%). On the other hand, SCCmec Type VI, X, XI and XIII were not found in any isolate. It was determined that four of the MRSA isolates (3.4%) carried the PVL gene that two (50%) of these were found in SCCmec Type VIII.
CONCLUSION
Monitoring of FOX resistance is an effective and safe method for determination of MRSA isolates. The change in the mec gene causes resistance, which should be monitored regularly with molecular methods. Our study is the first study in Turkey.
PubMed: 38876184
DOI: 10.1016/j.ijmmb.2024.100649 -
JMIR AI May 2024Health care-associated infections due to multidrug-resistant organisms (MDROs), such as methicillin-resistant Staphylococcus aureus (MRSA) and Clostridioides difficile...
BACKGROUND
Health care-associated infections due to multidrug-resistant organisms (MDROs), such as methicillin-resistant Staphylococcus aureus (MRSA) and Clostridioides difficile (CDI), place a significant burden on our health care infrastructure.
OBJECTIVE
Screening for MDROs is an important mechanism for preventing spread but is resource intensive. The objective of this study was to develop automated tools that can predict colonization or infection risk using electronic health record (EHR) data, provide useful information to aid infection control, and guide empiric antibiotic coverage.
METHODS
We retrospectively developed a machine learning model to detect MRSA colonization and infection in undifferentiated patients at the time of sample collection from hospitalized patients at the University of Virginia Hospital. We used clinical and nonclinical features derived from on-admission and throughout-stay information from the patient's EHR data to build the model. In addition, we used a class of features derived from contact networks in EHR data; these network features can capture patients' contacts with providers and other patients, improving model interpretability and accuracy for predicting the outcome of surveillance tests for MRSA. Finally, we explored heterogeneous models for different patient subpopulations, for example, those admitted to an intensive care unit or emergency department or those with specific testing histories, which perform better.
RESULTS
We found that the penalized logistic regression performs better than other methods, and this model's performance measured in terms of its receiver operating characteristics-area under the curve score improves by nearly 11% when we use polynomial (second-degree) transformation of the features. Some significant features in predicting MDRO risk include antibiotic use, surgery, use of devices, dialysis, patient's comorbidity conditions, and network features. Among these, network features add the most value and improve the model's performance by at least 15%. The penalized logistic regression model with the same transformation of features also performs better than other models for specific patient subpopulations.
CONCLUSIONS
Our study shows that MRSA risk prediction can be conducted quite effectively by machine learning methods using clinical and nonclinical features derived from EHR data. Network features are the most predictive and provide significant improvement over prior methods. Furthermore, heterogeneous prediction models for different patient subpopulations enhance the model's performance.
PubMed: 38875598
DOI: 10.2196/48067 -
Medicine Jun 2024In Algeria, the issue of antibiotic resistance is on the rise, being the Staphylococcus aureus infection as a significant concern of hospital-acquired infections. The... (Observational Study)
Observational Study
In Algeria, the issue of antibiotic resistance is on the rise, being the Staphylococcus aureus infection as a significant concern of hospital-acquired infections. The emergence of antibiotic resistance in this bacterium poses a worldwide challenge. The aim of this study aims to establish the incidence of S aureus strains in Algeria as well as identify phenotypic and genotypic resistance based on the "mecA" and "nuc" genes. From 2014 to 2017, a total of 185 S aureus strains were isolated from patients at a hospital in the city of Rouïba, Algiers the number of isolates was slightly higher in males at 58.06% compared to females at 41.94%, resulting in a sex ratio of 1.38. the Oxacillin and Cefoxitin DD test (1 μg oxacillin disk and 30 μg cefoxitin disk) identified 42 strains as resistant. The results indicated high resistance to lactam antibiotics, with penicillin having a 100% resistance rate. There was also significant resistance to oxacillin (51.25%) and cefoxitin (50%). This resistance was frequently associated with resistance to other antibiotic classes, such as aminoglycosides (50%) and Macrolides (28.29%). To confirm methicillin-resistant characteristics, a polymerase chain reaction (PCR) multiplex was conducted on 10 isolates (6 SARM; 4 MSSA) on a phenotypic level. Three isolates tested positive for "mecA," while 7 were negative. All strains carry the nuc gene, which is specific to S aureus. In Algeria, the incidence of S aureus resistance is slightly lower compared to other countries, but it is increasing over time. It is now more crucial than ever to restrict the proliferation of multidrug-resistant strains and reduce undue antibiotic prescriptions. To achieve this, it is vital to keep updated on the epidemiology of this bacterium and its antibiotic susceptibility. This will enable the formulation of appropriate preventive control measures to manage its progression.
Topics: Humans; Anti-Bacterial Agents; Female; Male; Staphylococcus aureus; Staphylococcal Infections; Algeria; Prevalence; Microbial Sensitivity Tests; Bacterial Proteins; Oxacillin; Adult; Penicillin-Binding Proteins; Cefoxitin; Middle Aged; Micrococcal Nuclease; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Methicillin-Resistant Staphylococcus aureus
PubMed: 38875387
DOI: 10.1097/MD.0000000000038562 -
PloS One 2024[This corrects the article DOI: 10.1371/journal.pone.0212052.].
Correction: Asymptomatic carriage of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, Group A Streptococcus and Staphylococcus aureus among adults aged 65 years and older.
[This corrects the article DOI: 10.1371/journal.pone.0212052.].
PubMed: 38875252
DOI: 10.1371/journal.pone.0305830 -
JAMA Network Open Jun 2024Oral non-β-lactam antibiotics are commonly used for empirical therapy of Staphylococcus aureus infections, especially in outpatient settings. However, little is known...
IMPORTANCE
Oral non-β-lactam antibiotics are commonly used for empirical therapy of Staphylococcus aureus infections, especially in outpatient settings. However, little is known about potential geographic heterogeneity and temporal trends in the prevalence of S aureus resistance to non-β-lactams in the US.
OBJECTIVE
To characterize the spatiotemporal trends of resistance to non-β-lactam antibiotics among community-onset S aureus infections, including regional variation in resistance rates and geographical heterogeneity in multidrug resistance.
DESIGN, SETTING, AND PARTICIPANTS
This cross-sectional study used data from Veterans Health Administration clinics collected from adult outpatients with S aureus infection in the conterminous 48 states and Washington, DC, from January 1, 2010, to December 31, 2019. Data were analyzed from January to November 2023.
EXPOSURES
Resistance to lincosamides (clindamycin), tetracyclines, sulfonamides (trimethoprim-sulfamethoxazole [TMP-SMX]), and macrolides.
MAIN OUTCOMES AND MEASURES
Spatiotemporal variation of S aureus resistance to these 4 classes of non-β-lactam antibiotics, stratified by methicillin-resistant S aureus (MRSA) and methicillin-sensitive S aureus (MSSA), and subdivided by regions of the US (Northeast, Midwest, South, and West). Trend tests and bivariate mapping were used to determine significant changes in resistant proportions over time and identify counties where rates of resistance to multiple non-β-lactams were high.
RESULTS
A total of 382 149 S aureus isolates from 268 214 unique outpatients (mean [SD] age, 63.4 [14.8] years; 252 910 males [94.29%]) were analyzed. There was a decrease in the proportion of MRSA nationwide, from 53.6% in 2010 to 38.8% in 2019. Among MRSA isolates, we observed a significant increase in tetracycline resistance (from 3.6% in 2010 to 12.8% in 2019; P for trend < .001) and TMP-SMX resistance (from 2.6% in 2010 to 9.2% in 2019; P for trend < .001), modest and not significant increases in clindamycin resistance (from 24.2% in 2010 to 30.6% in 2019; P for trend = .34), and a significant decrease in macrolide resistance (from 73.5% in 2010 to 60.2% in 2019; P for trend < .001). Among MSSA isolates, significant upward trends in clindamycin, tetracyclines, and TMP-SMX resistance were observed. For example, tetracycline resistance increased from 3.7% in 2010 to 9.1% in 2019 (P for trend < .001). Regional stratification over time showed that the Northeast had slightly higher rates of clindamycin resistance but lower rates of tetracycline resistance, while the South had notably higher rates of resistance to tetracyclines and TMP-SMX, particularly among MRSA isolates. Bivariate mapping at the county scale did not indicate clear regional patterns of shared high levels of resistance to the 4 classes of antimicrobials studied.
CONCLUSIONS AND RELEVANCE
In this study of outpatient S aureus isolates, MRSA became less common over the 10-year period, and MRSA isolates were increasingly resistant to tetracyclines and TMP-SMX. Geographic analysis indicated no spatial overlap in counties with high rates of resistance to both tetracyclines and TMP-SMX. Examining the regional spatial variation of antibiotic resistance can inform empirical therapy recommendations and help to understand the evolution of S aureus antibiotic resistance mechanisms.
Topics: Humans; Cross-Sectional Studies; Staphylococcal Infections; Male; Female; Staphylococcus aureus; Middle Aged; Anti-Bacterial Agents; Outpatients; United States; Aged; Adult; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Drug Resistance, Bacterial
PubMed: 38874923
DOI: 10.1001/jamanetworkopen.2024.17199 -
Food Science & Nutrition Jun 2024During the last decade, nanotechnology has attained a significant place among the scientific community for the biosynthesis of plant-based nanoparticles owing to its...
During the last decade, nanotechnology has attained a significant place among the scientific community for the biosynthesis of plant-based nanoparticles owing to its effective, safe, and eco-friendly nature. Hence, keeping in view the significance of nanotechnology, the current study was conducted to develop, characterize (UV-visible spectroscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy), and assess the antimicrobial (antibacterial and antifungal) properties of L. Extract-based Gold (Au) and Silver (Ag) nanoparticles (NPs). Characteristic absorption peaks at 420 and 540 nm revealed the formation of AgNPs and AuNPs, respectively. SEM images revealed that both silver and gold nanoparticles were oval and spherical with average size ranging from 42 to 72 and 12.6 to 35.7 nm, respectively. Similarly, FT-IR spectra revealed that the functional groups such as hydroxyl, carboxyl, and polyphenolic groups of biomolecules present in the extract are possibly responsible for reducing metallic ions and the formation of nanoparticles. Likewise, the EDX analysis confirmed the presence of silver and gold in synthesized NPs. Furthermore, the AgNPs and AuNPs showed good antibacterial and antifungal activities. The maximum antibacterial and antifungal activity was noticed for extract against (21 mm) and (18 mm), respectively. Whereas, the maximum antibacterial and antifungal activities of synthesized AgNPs were observed against (25 mm) and (36 mm), respectively. Moreover, in the case of AuNPs, the highest antibacterial and antifungal activity of synthesized AuNPs was noticed against (25 mm) and (31 mm), respectively. Findings of this study revealed that extract and biosynthesized NPs (silver and gold) possessed significant antibacterial and antifungal properties against different bacterial (, , , , and ) and fungal (, , and ) strains. Further studies must be carried out to assess the probable mechanism of action associated with these antimicrobial properties.
PubMed: 38873463
DOI: 10.1002/fsn3.4112 -
Food Science & Nutrition Jun 2024Sausage is susceptible to oxidative changes in lipids and microbial spoilage due to the presence of water, fat, protein, and vitamins. Bee pollen (BP) as a source of...
Sausage is susceptible to oxidative changes in lipids and microbial spoilage due to the presence of water, fat, protein, and vitamins. Bee pollen (BP) as a source of potential antioxidants and antibacterial compounds can effectively prevent lipid peroxidation and microbial spoilage in meat products. The aim of the present study was to investigate the antibacterial and antioxidant activities of BP and the effects of nano/microparticles of bee pollen extract (n/m BP) at a concentration of 125 and 250 mg/100 g meat on the oxidative stability and microbial growth of high-fat sausage during 30 days of storage at 4°C. The formation of BP particles in the nano/micro range was confirmed by scanning electron microscopy. High concentrations of total phenolic compounds (28.26 ± 0.10 mg GAE/g BP) with antioxidant activity (EC = 5.4 ± 0.07 mg/mL) were detected in BP. Based on the microdilution assay, the minimum inhibitory concentration of n/m BP for all test bacteria was 1000 (μg/mL) and the minimum bactericidal concentration of n/m BP was 2000 (μg/mL) for and and 4000 (μg/mL) for and . The n/m BP treatment (250 mg/100 g meat) showed a higher pH value ( < .05) and lower TBARS values ( < .05) than the ascorbic acid treatment (100 mg/100 g meat) and the control during the storage period. The microbial analysis showed that the addition of n/m BP led to a significant decrease ( < .05) in the total bacterial count, coliforms, , and fungal population compared to the other samples. The results show that the addition of n/m BP (125 mg/100 g) can improve the texture, taste, and overall acceptability of the sausage compared to the control sample. In conclusion, this study suggests that BP can replace synthetic antioxidants in high-fat sausages at the nano/microparticle level.
PubMed: 38873449
DOI: 10.1002/fsn3.4086 -
Food Science & Nutrition Jun 2024Coriander ( L.) is an annual herb belonging to the Apiaceae family that is grown worldwide. This aromatic herb has been used for its nutritional value and biological...
Coriander ( L.) is an annual herb belonging to the Apiaceae family that is grown worldwide. This aromatic herb has been used for its nutritional value and biological properties. In this study, we compared the essential oil composition and antibacterial activity of coriander seeds from nine Iranian and Iraqi populations for the first time. The seed oils were extracted using a Clevenger-type apparatus, and their chemical composition was determined using GC and GC/MS Agilent apparatuses. The antimicrobial activity of the oils was tested against three infectious bacteria (, , and ) using the agar well diffusion method. The experiments were repeated three times, and the results were analyzed using PAST, SAS, and SPSS software. The results showed that oxygenated monoterpenes, especially linalool, were the major compounds in the oils, followed by α-pinene, γ-terpinene, and geranyl acetate. The proportions of these compounds varied among the populations. Trace amounts of other compounds were also detected, some of which were only found in certain populations. The populations were detected as linalool chemotype, and classified into four groups based on their chemical constituents in the UPGMA tree. The PCA-Biplot showed that these groups were characterized by the presence and percentage of specific compounds. The essential oils showed bacterial growth inhibitory properties only at 100% concentration. was the most sensitive bacterium to the coriander essential oil, while the essential oils of all populations inhibited the growth of this bacterium. Additionally, the essential oils were more effective than antibiotics against . These findings contribute to our understanding of coriander seed essential oil by providing data on antibacterial activity and chemical characteristics. Furthermore, the study highlights the importance of selecting populations based on their specific essential oil profiles for antibacterial applications.
PubMed: 38873442
DOI: 10.1002/fsn3.4047 -
Frontiers in Microbiology 2024Microorganisms in biofilms are particularly difficult to control because of their increased survival and antibiotic resistance. Allicin and domiphen were employed to...
BACKGROUND
Microorganisms in biofilms are particularly difficult to control because of their increased survival and antibiotic resistance. Allicin and domiphen were employed to inhibit the microbial growth and biofilm formation of , , and strains.
METHODS
Broth microdilution method and checkerboard assay were conducted to determine the efficacy of allicin combined with domiphen against , , and . Microbial biofilm formation was measured using the crystal violet staining method and fluorescence microscopy. And the total viable count of the biofilm cells on material surface after the treatment with antimicrobial reagents was calculated with the plate count technique.
RESULTS
The two drugs showed synergistic effects against the pathogens with a fractional bactericidal concentration of less than 0.38. The combination of 64 μg/mL allicin with 1 μg/mL domiphen dispersed over 50% of the biofilm mass of , , and . In addition, the drug combination reduced the total viable counts of and biofilm cells on stainless steel and polyethylene surfaces by more than 10 CFU/mL.
CONCLUSION
The combination of allicin and domiphen is an effective strategy for efficiently decreasing biofilms formation on various industrial materials surfaces.
PubMed: 38873153
DOI: 10.3389/fmicb.2024.1341316 -
F1000Research 2024Tigecycline, a glycylcycline antibiotic is a promising option for the treatment of single or multidrug resistant pathogens. The aim of the study was to evaluate the...
BACKGROUND
Tigecycline, a glycylcycline antibiotic is a promising option for the treatment of single or multidrug resistant pathogens. The aim of the study was to evaluate the in-vitro Tigecycline susceptibility of various pathogens from clinical samples received at the tertiary care hospitals in South India.
METHODS
The analysis of specimens from patients admitted were carried out in this prospective cross sectional study. The identification and antimicrobial susceptibility testing was performed by semi-automated Vitek 2 systems and Kirby Bauer method. Pattern of data analysis was done by descriptive statistics.
RESULTS
Among 2574 isolates, 812 isolates were Gram positive pathogens and 1762 isolates were Gram negative pathogens. Resistance to Tigecycline was more common among Gram negative pathogens (18.62%) in comparison to the Gram positive pathogens (0.49%). Among 740 Extended Spectrum Beta Lactamases (ESBL) producers such as species & , 629 isolates were susceptible, and 93 isolates were resistant to the tigecycline. All the methicillin resistant (MRSA) isolates were susceptible to tigecycline.
CONCLUSION
Multidrug resistant (MDR) pathogens like species, and species were found to be highly effective to tigecycline for elimination of infections caused by both Gram positive and Gram negative pathogens. The use of combination therapy becomes crucial to prevent the development of Pan Drug resistance.
Topics: Tigecycline; Humans; Tertiary Care Centers; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Anti-Bacterial Agents; Cross-Sectional Studies; Minocycline; Gram-Negative Bacteria; Prospective Studies; India; Gram-Positive Bacteria
PubMed: 38872735
DOI: 10.12688/f1000research.141535.2