Search Results (82)

Background: Influenza B usually causes mild illness in children. Severe and fatal cases can occur when complicated by secondary Staphylococcus aureus (S. aureus) pneumonia, including community-acquired methicillin-resistant Staphylococcus aureus (MRSA). We present a rare, rapidly progressive fatal case in an adolescent with no known medical history to highlight diagnostic and therapeutic pitfalls. Case Presentation: A 16-year-old boy with no known underlying conditions (unvaccinated for influenza) presented critically ill at “Sf. Ioan” Clinical Emergency Pediatric Hospital in Galați after one week of high fever and cough. He was in respiratory failure with septic shock, requiring immediate intubation and vasopressors. Chest X-ray (CXR) showed diffuse bilateral infiltrates (acute respiratory distress syndrome, ARDS). Initial laboratory tests revealed leukopenia, severe thrombocytopenia, disseminated intravascular coagulation (DIC), rhabdomyolysis, and acute kidney injury (AKI). Reverse transcription polymerase chain reaction (RT-PCR) confirmed influenza B, and blood cultures grew MRSA. Despite maximal intensive care, including mechanical ventilation, antibiotics (escalated for MRSA), antiviral therapy, and cytokine hemoadsorption therapy, the patient developed refractory multi-organ failure and died on hospital day 6. Autopsy revealed bilateral necrotizing pneumonia (NP) without radiographic cavitation, underscoring the diagnostic challenge. Discussion: The initial chest radiography showed diffuse bilateral pulmonary infiltrates, predominantly in the lower zones, with an ill-defined, patchy, and confluent appearance. Such appearance, in our case, was more suggestive of rapid progressive NP caused by MRSA rather than the typical pneumococcal one. This is one of the few reported cases of influenza B–MRSA coinfection with fulminant rhabdomyolysis and autopsy-confirmed necrosis. Our fulminant case illustrates the synergistic virulence of influenza and MRSA. Toxin-producing MRSA strains can cause NP and a “cytokine storm,” causing capillary leak, ARDS, shock, and DIC. Once multi-organ failure ensues, the prognosis is grim despite aggressive care. The absence of early radiographic necrosis and delayed anti-MRSA therapy (initiated after culture results) likely contributed to the poor outcome. Conclusions: Influenza B–MRSA co-infection, though rare, demands urgent empiric anti-MRSA therapy in severe influenza cases with leukopenia or shock, even without radiographic necrosis. This fatal outcome underscores the dual imperative of influenza vaccination and early, aggressive dual-pathogen targeting in high-risk presentations. Full article

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of healthcare-associated infections in Europe. It has become increasingly prevalent in community settings, causing skin and soft tissue infections (SSTIs). Managing community-acquired (CA) MRSA infections is challenging due to its high virulence and resistance to common antibiotics, and prevention outside the hospital setting is complex. Combination therapy has demonstrated efficacy in the treatment of severe MRSA infections. Furthermore, surgical source control is critical in treating CA-MRSA infections, involving removing the primary infection site to interrupt bacterial replication. Timeliness and a correct surgical approach are essential for successful treatment outcomes and improved quality of life. Methods: This report details the case of a 15-year-old athlete who was admitted to the intensive care unit with septic shock caused by CA-MRSA. Results: Despite initial treatment, his condition rapidly worsened. A computed tomography (CT) scan identified multiple abscesses (in the lungs, limbs, thyroid, and subscapular region) along with other complications. To achieve adequate tissue concentrations at all affected sites, a triple-targeted antimicrobial therapy was initiated and adjusted based on therapeutic drug monitoring (TDM). At the same time, daily surgical debridement was performed. The patient responded significantly to this treatment, and blood cultures eventually returned negative. Conclusions: A multidisciplinary approach involving early source control, tailored antimicrobial therapy, and, if monotherapy fails to control infection, combination therapy is advisable to treat life-threatening CA-MRSA infections. Full article

Background and Objectives: Despite extensive research on the sources and transmission pathways of Hospital-Acquired Infections (HAIs), the role of cleaning staff as potential vectors has been under-explored. This study addresses the gap by examining the cleaning staff’s role in nosocomial infection transmission, focusing on pathogenic bacteria and fungi colonization. Identifying potential pathogens harbored by cleaning staff that carry the risk of causing HAIs, especially methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae. Materials and Methods: This current cross-sectional study was conducted on 96 cleaning staff at King Fahad Hospital of the University and Family and Community Medicine-Centre, Eastern Province, Saudi Arabia. Sample collection targeted hands and nostrils using cotton swabs, followed by laboratory testing, including MALDI-TOF mass spectrometry for bacterial identification, and the cefoxitin disc diffusion test for the screening of MRSA. Results: In total, the occurrence of MRSA colonization was 9.4% while Enterobacteriaceae colonization was 15.6%. No significant correlation was found for MRSA among departments or between day and night shifts. Alternatively, individuals working in the ICU and the operating room showed higher chances of being colonized by Enterobacteriaceae, and a notable connection was identified between Enterobacteriaceae and day shifts. Ultimately, the frequency of handwashing reduced the chances of being colonized by MRSA and Enterobacteriaceae, underscoring the significance of good hygiene practices. Conclusions: The study highlights the potential role of cleaning staff in transmitting HAIs, indicating a need for further research and consideration of enhanced hygiene protocols in hospital settings. Full article

Bacterial antibiotic resistance represents a major healthcare problem. In 2019, 4.95 million deaths were associated with antibiotic resistance, and it is estimated that, by 2050, up to 3.8% of the global gross domestic product could be lost due to this problem. Methicillin-resistant Staphylococcus aureus is one of the leading sources of hospital-acquired infections associated with increased mortality, length of hospital stay, and higher cost of treatment. Here, we describe the de novo synthesis of a library of 22 triazeneindole derivatives with high activity against a wide panel of multidrug-resistant MRSA clinical isolates. Leading compound BX-SI043 (ethyl 6-fluoro-3-[pyrrolidin-1-yl-azo]-1H-indole-2-carboxylate) showed high activity (minimal inhibitory concentration range, 0.125–0.5 mg/L) against 41 multidrug-resistant MRSA strains, as well as relatively low in vitro cytotoxicity (selectivity index, 76) and in vivo acute toxicity (maximum tolerated dose, 600 mg/kg), via intragastric administration in rats. These data suggest that BX-SI043 is a promising drug candidate for the development a novel MRSA treatment. Full article

Staphylococcus aureus (S. aureus) is a Gram-positive bacterium of significant clinical importance, known for its versatility and ability to cause a wide array of infections, such as osteoarticular, pulmonary, cardiovascular, device-related, and hospital-acquired infections. This review describes the most recent evidence of the pathogenic potential of S. aureus, which is commonly part of the human microbiota but can lead to severe infections. The prevalence of pathogenic S. aureus in hospital and community settings contributes to substantial morbidity and mortality, particularly in individuals with compromised immune systems. The immunopathogenesis of S. aureus infections involves intricate interactions with the host immune and non-immune cells, characterized by various virulence factors that facilitate adherence, invasion, and evasion of the host’s defenses. This review highlights the complexity of S. aureus infections, ranging from mild to life-threatening conditions, and underscores the growing public health concern posed by multidrug-resistant strains, including methicillin-resistant S. aureus (MRSA). This article aims to provide an updated perspective on S. aureus-related infections, highlighting the main diseases linked to this pathogen, how the different cell types, virulence factors, and signaling molecules are involved in the immunopathogenesis, and the future perspectives to overcome the current challenges to treat the affected individuals. Full article

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant burden globally, particularly in the Arabian Gulf region. The United Arab Emirates (UAE) has experienced rising MRSA prevalence, with increasing diversity in the clonal complexes (CCs) identified. The COVID-19 pandemic, with its increased hospitalization rates and antibiotic use, may have further influenced MRSA’s genetic evolution and epidemiology in the country. Methods: To investigate this influence, genomic profiling of 310 MRSA clinical isolates collected between February and November 2022 was performed using a DNA microarray-based assay. Results: Isolates were assigned to 22 clonal complexes and 72 distinct strain assignments. The predominant clonal complexes were CC5, CC6, CC361, CC22, CC1, and CC8. Community-acquired MRSA lineages were dominant, with only one healthcare-associated MRSA lineage isolate identified. Upward trends of CC1153 were observed along with rare CCs, such as CC121-MRSA and CC7-MRSA, with the latter being reported for the first time in the Arabian Gulf region. The presence of pandemic strains USA300 CC8-MRSA-[IVa + ACME1] and CC8-MRSA-IV strains were also observed, including variants lacking Panton–Valentine leukocidin (pvl) genes and missing tst1 or enterotoxin genes. The PVL-negative CC772-MRSA-V/VT was identified, representing its first report in the UAE. A novel variant, CC361-MRSA-IV (tst1+/PVL+), was identified. Pvl genes were observed in 36% of the isolates, primarily from skin and soft tissue infections, while fusC (SCC-borne fusidic acid resistance) was identified in 13% of the isolates. Conclusions: The findings highlight the ongoing evolution of MRSA in the UAE, with the persistence and emergence of diverse and rare clonal complexes, driving the need for continuous genomic surveillance. Full article

Meticillin-resistant Staphylococcus aureus (MRSA) is a significant cause of hospital-acquired infections (HAIs), posing a serious threat to healthcare workers (HCWs). All touching behavior data were from a clinical skills competition of a medical school in Hong Kong; more than 12,000 touches involving 3 patients (infusion, critically ill, and agitation) and 25 HCWs were collected. A fomite transmission model considering real touch behaviors was established to simulate the MRSA transmission in an emergency room, then the MRSA exposure risk of HCWs and effectiveness of interventions were analyzed. HCWs had a low touch frequency of facial mucous (doctors: 1.7 times/h; nurses: 1.1 times/h). The MRSA intake fractions for doctors were 2–4 times higher than those for nurses. Handwashing twice per hour could reduce the MRSA intake fraction by 7%. Effectiveness of disinfecting only the top 10 high-risk public surfaces was 83% to 98% of the efficiency when disinfecting all public surfaces. MRSA mainly transferred via hand contact contributed over 89% of pathogen transmission. Therefore, disinfecting public surfaces or replacing them with antimicrobial surfaces was not effective. The findings highlight the importance of prioritizing hand hygiene among HCWs and optimizing interventions to enhance infection-control protocols in emergency rooms. And this study provides scientific evidence for the development of precise interventions for MRSA prevention and control in hospital emergency rooms. Full article

Background/Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) can cause cases of community-acquired pneumonia, hospital-acquired pneumonia, and ventilator-associated pneumonia, and nasal colonization with this pathogen increases the risk of infection. Due to its high negative predictive value, multiple studies support using the MRSA nasal polymerase chain reaction (PCR) test to discontinue antimicrobials that target MRSA in the setting of a negative test result. The purpose of this project was to assess the utility of a protocol to allow pharmacists the ability to order MRSA nasal PCR screenings in hospitalized patients with pneumonia. Results: The pre-protocol group included a random sample of 100 patients, and the post-protocol group included 625 patients. Vancomycin DOTs when pharmacists ordered PCRs were significantly lower compared to the pre-protocol group (p < 0.5; 95% CI, 0.46–2.24). The average length of stay and readmission rates at 30 days were significantly lower in the post-protocol group compared to the pre-protocol group (p < 0.05 and p = 0.02, respectively), but there was no significant difference in mortality (p = 0.33). Methods: A protocol was implemented at our institution that allowed pharmacists to order an MRSA nasal PCR test in patients with pneumonia. This retrospective chart review compared a cohort of patients who received vancomycin from before implementation of the protocol to patients who received vancomycin after the protocol’s implementation. The primary endpoint was vancomycin days of therapy (DOTs) between the pre-protocol group and the post-protocol group. Other endpoints assessed included the length of hospitalization, readmission rates, and mortality. Conclusions: Pharmacists ordering MRSA nasal PCR tests significantly reduced vancomycin DOTs, average length of stay, and 30-day readmission rates, contributing to positive outcomes in patients with pneumonia. Full article

Sequence-type 5 (ST5) of methicillin-resistant Staphylococcus aureus (MRSA), harboring the staphylococcal chromosomal cassette mec type IV (SCCmecIV), was first detected in Portugal. It emerged as a significant cause of healthcare-associated (HA) infection in pediatric units and was hence named the pediatric clone. Another ST5 lineage, which carries SCCmecII, also prevailed in the USA and Japan for multiple years. More recently, another MRSA lineage, ST105-SCCmecII, part of the evolution of clonal complex 5 (CC5) MRSA, has emerged as the cause of hospital-acquired bloodstream infection outbreaks in countries including Portugal, the USA, and Brazil. This article reviews studies on the epidemiology and evolution of these newly emerging pathogens. To this end, a search of PUBMED from inception to 2024 was performed to find articles reporting the occurrence of ST105 MRSA in epidemiologic studies. A second search was performed to find studies on MRSA, CC5, ST5, and SCCmecII. A search of PUBMED from 1999 to 2024 was also performed to identify studies on the genomics and evolution of ST5, CC5, and ST105 MRSA. Further studies were identified by analyzing the references of the previously selected articles from PUBMED. Most articles on ST105 MRSA were included in this review. Only articles written in English were included. Furthermore, only studies that used a reliable genotyping method (e.g., whole genome sequencing, or MLST) to classify the CC5 lineages were selected. The quality and selection of articles were based on the consensus assessment of the three authors in independent evaluations. In conclusion, ST105-SCCmecII is an emerging MRSA in several countries, being the second/third most important CC5 lineage, with a relatively high frequency in bloodstream infections. Of concern is the increased mortality from BSI in patients older than 15 years and the higher prevalence of ST105-SCCmecII in the blood of patients older than 60 years reported in some studies. Full article

The aim of this work was to synthesize, characterize and apply advanced antimicrobial biocompatible electrospun polymers suitable for medical implants for surgical repairs. Injuries to the musculoskeletal system often necessitate surgical repair, but current treatments can still lead to high failure rates, such as 40% for the repair of rotator cuff tears. Therefore, there is an urgent need for the development of new biocompatible materials that can effectively support the repair of damaged tissues. Additionally, infections acquired during hospitalization, particularly those caused by antibiotic-resistant bacteria, result in more fatalities than AIDS, tuberculosis, and viral hepatitis combined. This underscores the critical necessity for the advancement of antimicrobial implants with specialized coatings capable of combating Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA), two strains notoriously known for their antibiotic resistance. Therefore, we developed an antimicrobial coating incorporating nanoparticle mixtures using the sol-gel process and applied it to electrospun polycaprolactone (PCL) filaments, followed by thorough characterization by using spectroscopic (FTIR, Raman, NMR) microscopic (SEM and SEM-EDX), and tensile test. The results have shown that the integration of electro-spinning technology for yarn production, coupled with surface modification techniques, holds significant potential for creating antimicrobial materials suitable for medical implants for surgical repairs. Full article

The emergence of antimicrobial resistance (AMR) in pathogens and their spillover into the environment have become a global public health menace. Insects can acquire these pathogens from the environment and would serve as mechanical and biological vectors. The current study assessed the ability of Culex quinquefasciatus mosquitoes to acquire methicillin-resistant Staphylococcus aureus (MRSA) through the exposure of the mosquitoes to the pathogen via rearing water, blood feed, or a feeding membrane under laboratory conditions. In addition, mosquito immatures collected from their habitat in the vicinity of hospitals, veterinary dispensaries, and butcher shops at 15 study sites in Puducherry were screened for MRSA infection. All samples were subjected to the culture-based isolation of S. aureus from the surface and homogenate. The presence of the S. aureus-specific nuc gene and the genes that confer resistance to methicillin (mecA and mecC) were screened using PCR tests. MRSA was not evident either on the external surface or in the homogenate of the mosquitoes emerging from the larvae reared in the MRSA-spiked water or those fed with MRSA through blood or smeared membranes. Furthermore, the presence of MRSA was not evident in any of the field-caught mosquitoes. Hence, we conclude that C. quinquefasciatus mosquitoes are impervious to MRSA colonization. Full article

Staphylococcal scalded skin syndrome (SSSS) is a rare, toxin-mediated, desquamating bacterial infectious dermatosis. So far, data from Southwestern China is scarce. This study aimed to investigate the clinical characteristics of SSSS patients in our hospital, the relative proportion of methicillin-resistant Staphylococcus aureus (MRSA) in skin and soft tissue secretions, and the drug sensitivity of S. aureus to better assist dermatologists in the diagnosis and treatment of SSSS. We reviewed the demographic characteristics, clinical manifestations, treatment regimens, therapeutic efficacy, laboratory test results, drug sensitivity, and outcome data of 79 SSSS patients from January 2012 to December 2021. Statistical analysis was performed using t tests and chi-square tests. Among the 79 SSSS patients, MRSA was detected in 35 (44.3%) isolates: 34 community-acquired (CA)-MRSA (97.1%) and 1 hospital-acquired (HA)-MRSA. The SSSS incidence increased annually from 2012 to 2014 and then decreased gradually after peaking in 2015. All the isolates were sensitive to vancomycin, tigecycline, linezolid, moxifloxacin, levofloxacin, and ciprofloxacin; were completely resistant to penicillin; and had low sensitivity to clindamycin and erythromycin. Interestingly, the sensitivity of MRSA to tetracycline increased annually after 2015. The resistance rates to common drugs previously used to treat SSSS increased. These findings may accelerate diagnosis and improve empirical antibiotic use, suggesting that clinicians should prescribe drugs according to antimicrobial susceptibility. Full article

Background: During and after the COVID-19 pandemic, there was a suspicion of varying rates of respiratory tract infections (RTIs), particularly pneumonia (PN). Methods: This research evaluated epidemiological indicators of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in the COVID-19 pandemic and post-pandemic period, including pathogens, ventilator-associated pneumonia (VAP), selected risk factors, and PN mortality. Results: At 1740 patients, throughout the 22,774 patient-days (Pt-D) and 18,039 ventilation days (Vt-D), there were 681 PN cases (39.14%): CAP 336 (19.31%) and HAP 345 (19.83%). CAP caused by SARS-CoV-2 was diagnosed in 257/336 (76.49%) patients. The clinical manifestations of PNs were CAP with 336/681 (49.34%), VAP with 232/681 (34.07%), and non-ventilator HAP (NV-HAP) with 113/681 cases (16.59%). The incidence rate of CAP/1000 Pt-D has been over 3 times higher in the pandemic period of 2020–2021 (20.25) than in the post-pandemic period of 2022 (5.86), p = 0.000. Similarly, higher incidence rates of VAP/1000 Pt-D were found in the pandemic period (p = 0.050). For NV-HAP, this difference was not statistically significant (p = 0.585). VAP occurred more frequently in the group of patients with PN in the course of COVID-19 compared to patients without COVID-19 (52/234 [22.2%] vs. 180/1506 [11.95%]); (p = 0.000). The most common CAP pathogen (during the pandemic) was SARS CoV-2 234/291 (80.4%), followed by MSSA/MRSA 8/291 (2.75%), whereas the most common VAP/NV-HAP pathogen was Acinetobacter baumannii XDR/MDR. The highest PN mortality was found in the patients with CAP caused by SARS-CoV-2 159/257 (61.87%). Conclusions: Pneumonias were diagnosed in nearly 40% of Intensive Care Unit (ICU) patients. Surveillance of pneumonias during the specific observation period was beneficial in the epidemiological and microbiological analysis of the ICU patients. Full article

Intracellular survival and immune evasion are typical features of staphylococcal infections. USA300 is a major clone of methicillin-resistant S. aureus (MRSA), a community- and hospital-acquired pathogen capable of disseminating throughout the body and evading the immune system. Carnosine is an endogenous dipeptide characterized by antioxidant and anti-inflammatory properties acting on the peripheral (macrophages) and tissue-resident (microglia) immune system. In this work, RAW 264.7 murine macrophages were infected with the USA300 ATCC BAA-1556 S. aureus strain and treated with 20 mM carnosine and/or 32 mg/L erythromycin. Stable small colony variant (SCV) formation on blood agar medium was obtained after 48 h of combined treatment. Whole genome sequencing of the BAA-1556 strain and its stable derivative SCVs when combining Illumina and nanopore technologies revealed three single nucleotide differences, including a nonsense mutation in the shikimate kinase gene aroK. Gene expression analysis showed a significant up-regulation of the uhpt and sdrE genes in the stable SCVs compared with the wild-type, likely involved in adaptation to the intracellular milieu. Full article

Methicillin-resistant (MR) Staphylococcus aureus (SA) and others, except for Staphylococcus aureus (SOSA), are common in healthcare-associated infections. SOSA encompass largely coagulase-negative staphylococci, including coagulase-positive staphylococcal species. Biofilm formation is encoded by the icaADBC operon and is involved in virulence. mecA encodes an additional penicillin-binding protein (PBP), PBP2a, that avoids the arrival of β-lactams at the target, found in the staphylococcal cassette chromosome mec (SCCmec). This work aims to detect mecA, the bap gene, the icaADBC operon, and types of SCCmec associated to biofilm in MRSA and SOSA strains. A total of 46% (37/80) of the strains were S. aureus, 44% (35/80) S. epidermidis, 5% (4/80) S. haemolyticus, 2.5% (2/80) S. hominis, 1.25% (1/80) S. intermedius, and 1.25% (1/80) S. saprophyticus. A total of 85% were MR, of which 95.5% showed mecA and 86.7% β-lactamase producers; thus, Staphylococcus may have more than one resistance mechanism. Healthcare-associated infection strains codified type I-III genes of SCCmec; types IV and V were associated to community-acquired strains (CA). Type II prevailed in MRSA mecA strains and type II and III in MRSOSA (methicillin-resistant staphylococci other than Staphylococcus aureus). The operon icaADBC was found in 24% of SA and 14% of SOSA; probably the arrangement of the operon, fork formation, and mutations influenced the variation. Methicillin resistance was mainly mediated by the mecA gene; however, there may be other mechanisms that also participate, since biofilm production is related to genes of the icaADBC operon and methicillin resistance was not associated with biofilm production. Therefore, it is necessary to strengthen surveillance to prevent the spread of these outbreaks both in the nosocomial environment and in the community. Full article