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Clinical Case Reports Jun 2024Methicillin-resistant staph aureus (MRSA) infections are challenging to treat, and with the emergence of community-associated MRSA (CA-MRSA) strains, early consideration...
Methicillin-resistant staph aureus (MRSA) infections are challenging to treat, and with the emergence of community-associated MRSA (CA-MRSA) strains, early consideration of this pathogen in populations without typical risk factors is critical. Here we present a case of CA-MRSA pneumonia that resulted in Community-acquired pneumonia (CAP) with septic shock, pyelonephritis, and muscle abscess.
PubMed: 38813451
DOI: 10.1002/ccr3.8957 -
Frontiers in Medicine 2024The emergence of community-acquired methicillin-resistant (CA-MRSA) infections at the end of the 20th century represents a significant shift in the epidemiology of...
The emergence of community-acquired methicillin-resistant (CA-MRSA) infections at the end of the 20th century represents a significant shift in the epidemiology of staphylococcal infections and, consequently, their clinical management. There are diverse CA-MRSA clones that are widely spread worldwide, showing differences in their regional dissemination, which has been dynamically changing over time. Although the first CA-MRSA description occurred about 30 years ago, its epidemiology in certain regions, such as South America, has been poorly explored, resulting in a gap in the understanding of the epidemiology of CA-MRSA in under-represented countries/regions. This report describes the first four clinical cases of invasive infections caused by CA-MRSA in a tertiary hospital in the central-southern region of Chile. It also associates the clinical characteristics of the infections with the microbiological and molecular features of the isolates. The four isolates belong to sequence type 8, which has been widely described as a cause of community-acquired infections. All of them presented a wide resistome and virulome. Additionally, in two of them, it was possible to reconstruct the COMER genetic element, present in the USA300-Latin American variant clone. Considering these findings, it is crucial to prepare for a potential increase in invasive CA-MRSA infections in Chile. This would involve enhancing current surveillance systems and maintaining a low threshold of suspicion for these infections among clinicians.
PubMed: 38813384
DOI: 10.3389/fmed.2024.1365756 -
Microbiology Spectrum May 2024Surveillance schemes for methicillin-resistant (MRSA) are widely established at the national and international levels. Due to the simple standardization of the...
Surveillance schemes for methicillin-resistant (MRSA) are widely established at the national and international levels. Due to the simple standardization of the protocol, mainly isolates from bloodstream infections are used. However, the limitations of this simple surveillance system are well described. We conducted a comprehensive analysis of MRSA isolates in a large Slovenian region over 5 years to identify the optimal sample group for assessing the overall MRSA diversity. At the same time, this study provides to date non-available molecular characterization of Slovenian MRSA isolates. A total of 306 MRSA isolates from various sources were sequenced and phenotypically tested for resistance. The isolates exhibited significant molecular diversity, encompassing 30 multi locus sequence type (MLST) sequence types (STs), 39 ST-SCC genetic lineages, 49 types, and 29 antibiotic resistance profiles. Furthermore, the isolate pool comprised 57 resistance genes, representing 22 resistance mechanisms, and 96 virulence genes. While bloodstream isolates, commonly used in surveillance, provided insights into frequently detected clones, they overlooked majority of clones and important virulence and resistance genes. Blood culture isolates detected 21.3% types, 24.1% resistance phenotypes, and 28.2% MLST-SCC profiles. In contrast, strains from soft tissues demonstrated superior genomic diversity capture, with 65.3% types, 58.6% resistance phenotypes, and 71.8% MLST-SCC profiles. These strains also encompassed 100.0% of virulence and 82.5% of resistance genes, making them better candidates for inclusion in surveillance programs. This study highlights the limitations of relying solely on bloodstream isolates in MRSA surveillance and suggests incorporating strains from soft tissues to obtain a more comprehensive understanding of the epidemiology of MRSA.IMPORTANCEIn this study, we investigated the diversity of methicillin-resistant (MRSA), a bacterium that can cause infections that are difficult to treat due to its resistance to antimicrobial agents. Currently, surveillance programs for MRSA mainly rely on isolates from bloodstream infections, employing a standardized protocol. However, this study highlights the limitations of this approach and introduces a more comprehensive method. The main goal was to determine which group of samples is best suited to understand the overall diversity of MRSA and to provide, for the first time, molecular characterization of Slovenian MRSA isolates. Our results suggest that including MRSA strains from soft tissue infections rather than just blood infections provides a more accurate and comprehensive view of bacterial diversity and characteristics. This insight is valuable for improving the effectiveness of surveillance programs and for developing strategies to better manage MRSA infections.
PubMed: 38809050
DOI: 10.1128/spectrum.00140-24 -
Open Veterinary Journal Apr 2024Globally, resistance to antimicrobial drugs is a major hazard to public health. Infections that were once easily treatable with antibiotics are becoming harder to...
BACKGROUND
Globally, resistance to antimicrobial drugs is a major hazard to public health. Infections that were once easily treatable with antibiotics are becoming harder to control, leading to prolonged illnesses, increased mortality rates, and higher healthcare costs.
AIM
This study intended to assess the antimicrobial, specifically the anti-Methicillin resistant (MRSA), and anticancer properties of different extracts obtained from (AHA).
METHODS
The antibacterial tests of AHA were performed on two Gram-negative bacterial strains ( and ), two Gram-positive bacterial strains (Methicillin-resistant (MRSA), and Staphylococcus aureus). Initial screening for antibacterial activities was conducted using the well diffusion technique. Subsequently, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined through the broth-dilution assay. The anticancer test was carried out on a human colorectal carcinoma cell line (HCT-116) using MTT assay.
RESULTS
Among all extracts, -hexane extract of AHA was the most effective against with the highest inhibition zone (24.67 mm ± 0.58) compared to standard antibiotic (erythromycin, 24.00 mm) followed by the methanolic extract against MRSA (24.00 mm ± 1.73). The methanol extract of AHA showed the highest antibacterial activity against MRSA. The results of MIC and MBC of the AHA methanol extract against MRSA were 1.17 ± 1.09 and 9.375 ± 0.0 mg/ml, respectively, demonstrating therapeutically significant antibacterial activity. Ethyl acetate extract has no antibacterial activity against and . The findings indicated that the methanol extract of AHA exhibited the highest efficacy against the colorectal carcinoma cell line (HCT-116), with an IC value of 126.61 ± 13.35 μg/ml.
CONCLUSION
These findings suggest that the methanol extract of AHA could be considered as a potential agent to serve as a source of antibacterial and anticancer compounds.
Topics: Plant Extracts; Anti-Bacterial Agents; Microbial Sensitivity Tests; Methicillin-Resistant Staphylococcus aureus; Humans; Jordan; Artemisia; Escherichia coli; Klebsiella pneumoniae
PubMed: 38808292
DOI: 10.5455/OVJ.2024.v14.i4.6 -
ACS Applied Engineering Materials May 2024In this work, we present a facile and scalable hydrolysis-based route for the synthesis of copper-doped TiO particles for highly effective light-activated antiviral and...
In this work, we present a facile and scalable hydrolysis-based route for the synthesis of copper-doped TiO particles for highly effective light-activated antiviral and antibacterial applications. The performance of the synthesized Cu-doped TiO particles is then evaluated using solution-phase antimicrobial photodynamic inactivation assays. We demonstrate that the Cu-doped TiO particles can successfully inactivate a wide range of pathogens with exposure to light for 90 min, including bacteria ranging from methicillin-resistant (99.9999%, ∼6 log units) to (99.93%, ∼3.3 log units), and viruses including feline calicivirus (99.94%, ∼3.4 log units) and HCoV-229E (99.996%, ∼4.6 log units), with the particles demonstrating excellent robustness toward photobleaching. Furthermore, a spray-coated polymer film, loaded with the synthesized Cu-doped TiO particles achieves inactivation of methicillin-resistant up to 99.998% (∼4.8 log units). The presented results provide a clear advance forward in the use of metal-doped TiO for aPDI applications, including the scalable synthesis (kg/day) of well-characterized and robust particles, their facile incorporation into a nontoxic, photostable coating that may be easily and cheaply applied to a multitude of surfaces, and a broad efficacy against drug-resistant Gram-positive and Gram-negative bacteria, as well as against enveloped and nonenveloped viruses.
PubMed: 38808269
DOI: 10.1021/acsaenm.4c00176 -
Cureus Apr 2024Methicillin-resistant (MRSA) hepatic phlegmon is a rare cause of fever of unknown origin (FUO) in an immunocompetent patient from a high-income country (HIC). MRSA...
Methicillin-resistant (MRSA) hepatic phlegmon is a rare cause of fever of unknown origin (FUO) in an immunocompetent patient from a high-income country (HIC). MRSA hepatic phlegmon is typically linked to protein malnutrition and chronic gastrointestinal infections in low- to middle-income countries while immunodeficiencies such as chronic granulomatous disease (CGD) are a more common cause in a HIC. Clinical manifestations of hepatic phlegmon can be vague and nonspecific making a complete FUO workup critical during evaluation. We report a case of MRSA hepatic phlegmon in an immunocompetent patient with a nonspecific history and physical exam findings. A 14-year-old male presented with an 11-day history of fever with mild bilateral upper quadrant abdominal pain. The patient also has mild upper quadrant pain with palpation. The patient was diagnosed with a hepatic phlegmon on abdominal ultrasound and computed tomography (CT) of the abdomen. He was started on antibiotics and Interventional Radiology placed drains into the phlegmon and performed vancomycin drain washes. Inflammatory markers were initially elevated and trended down with interventions. The patient did well with treatment and was back to baseline during outpatient follow-up with the Infectious Disease team. This case illustrates the importance of a complete workup in patients with FUO.
PubMed: 38807821
DOI: 10.7759/cureus.59229 -
Frontiers in Cellular and Infection... 2024and stand as notorious threats to human beings owing to the myriad of infections they cause. The bacteria readily form biofilms that help in withstanding the effects...
and stand as notorious threats to human beings owing to the myriad of infections they cause. The bacteria readily form biofilms that help in withstanding the effects of antibiotics and the immune system. Intending to combat the biofilm formation and reduce the virulence of the pathogens, we investigated the effects of carotenoids, crocetin, and crocin, on four Staphylococcal strains. Crocetin was found to be the most effective as it diminished the biofilm formation of ATCC 6538 significantly at 50 µg/mL without exhibiting bactericidal effect (MIC >800 µg/mL) and also inhibited the formation of biofilm by MSSA 25923 and at a concentration as low as 2 µg/mL, and that by methicillin-resistant MW2 at 100 µg/mL. It displayed minimal to no antibiofilm efficacy on the Gram-negative strains O157:H7 and as well as a fungal strain of . It could also curb the formation of fibrils, which partly contributes to the biofilm formation in . Additionally, the ADME analysis of crocetin proclaims how relatively non-toxic the chemical is. Also, crocetin displayed synergistic antibiofilm characteristics in combination with tobramycin. The presence of a polyene chain with carboxylic acid groups at its ends is hypothesized to contribute to the strong antibiofilm characteristics of crocetin. These findings suggest that using apocarotenoids, particularly crocetin might help curb the biofilm formation by and
Topics: Biofilms; Carotenoids; Vitamin A; Microbial Sensitivity Tests; Anti-Bacterial Agents; Staphylococcus epidermidis; Candida albicans; Staphylococcus aureus; Humans; Pseudomonas aeruginosa; Staphylococcus
PubMed: 38803574
DOI: 10.3389/fcimb.2024.1404960 -
Infection and Drug Resistance 2024Methicillin-resistant (MRSA) is a predominant nosocomial infection-causing bacteria. The aim of this study was to develop a novel single-bacteria multiplex digital PCR...
Methicillin-resistant (MRSA) is a predominant nosocomial infection-causing bacteria. The aim of this study was to develop a novel single-bacteria multiplex digital PCR assays (SMD-PCR), which is capable of simultaneously detecting and discriminating Methicillin-sensitive (MSSA) and MRSA. This protocol employed TaqMan probes to detect and genes, with the latter being linked to methicillin resistance. A total of 72 samples from various specimen types were evaluated. The accuracy rates for the sputum samples, pus samples, swab samples, ear secretion samples, and catheter samples were 94.44%, 100%, 92%, 100%, and 100%, respectively. Our results showed that the clinical practicability of SMD-PCR has applicability to the rapid detection of MRSA without DNA extraction or bacterial culture, and can be utilized for the rapid detection of and the timely identification of MRSA in clinical samples, thereby providing an advanced platform for the rapid diagnosis of clinical MRSA infection.
PubMed: 38803520
DOI: 10.2147/IDR.S464213 -
Scientific Reports May 2024Antibiotic resistance is a paramount global health issue, with numerous bacterial strains continually fortifying their resistance against diverse antibiotics. This surge...
Antibiotic resistance is a paramount global health issue, with numerous bacterial strains continually fortifying their resistance against diverse antibiotics. This surge in resistance levels primarily stems from the overuse and misuse of antibiotics in human, animal, and environmental contexts. In this study, we advocate for exploring alternative molecules exhibiting antibacterial properties to counteract the escalating antibiotic resistance. We identified a synthetic antimicrobial peptide (AMP) by using computational search in AMP public databases and further engineering through molecular docking and dynamics. Microbiological evaluation, cytotoxicity, genotoycity, and hemolysis experiments were then performed. The designed AMP underwent rigorous testing for antibacterial and antibiofilm activities against Methicillin-Resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), representing gram-positive and gram-negative bacteria, respectively. Subsequently, the safety profile of the AMP was assessed in vitro using human fibroblast cells and a human blood sample. The selected AMP demonstrated robust antibacterial and antibiofilm efficacy against MRSA and E. coli, with an added assurance of non-cytotoxicity and non-genotoxicity towards human fibroblasts. Also, the AMP did not demonstrate any hemolytic activity. Our findings emphasize the considerable promise of the AMP as a viable alternative antibacterial agent, showcasing its potential to combat antibiotic resistance effectively.
Topics: Biofilms; Methicillin-Resistant Staphylococcus aureus; Escherichia coli; Anti-Bacterial Agents; Humans; Antimicrobial Peptides; Microbial Sensitivity Tests; Molecular Docking Simulation; Hemolysis; Computer Simulation
PubMed: 38802469
DOI: 10.1038/s41598-024-58039-1 -
Revista Medica de Chile Jun 2023The primary objective of this study was to determine the prevalence of nasal colonization of methicillin resistant Staphylococcus aureus (MRSA) in medical students in... (Comparative Study)
Comparative Study
OBJECTIVES
The primary objective of this study was to determine the prevalence of nasal colonization of methicillin resistant Staphylococcus aureus (MRSA) in medical students in pre-clinical versus clinical courses at the Pontificia Universidad Católica de Chile and to describe the epidemiological, clinical and molecular pattern of the MRSA strains obtained.
METHOD
A cross-sectional descriptive study was carried out on 299 undergraduate and graduate medical students from the Pontificia Universidad Católica de Chile, 44 first-year students and 29 second-year students, corresponding to students of courses without regular clinical exposure and 26 sixth-year students, 58 seventh-year and 142 residents, who are daily exposed to hospital environments.
RESULTS
A carriage of 0% (0/73) was found in students not exposed to the clinic (pre-clinical courses) and 0.9% (2/226) in students of clinical courses, a difference that was not statistically significant (p-value 0.42).
CONCLUSIONS
The MRSA nasal carriage found in our medical students was low, finding positive samples only in students with clinical exposure. This prevalence is similar to the one reported in other studies in Chile with similar characteristics.
Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Chile; Students, Medical; Cross-Sectional Studies; Prevalence; Female; Male; Staphylococcal Infections; Carrier State; Young Adult; Adult; Nasal Cavity
PubMed: 38801377
DOI: 10.4067/s0034-98872023000600696