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PubMed2025

Genomic detection of Panton-Valentine Leucocidins encoding genes, virulence factors and distribution of antiseptic resistance determinants among Methicillin-resistant S. aureus isolates from patients attending regional referral hospitals in Tanzania.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a formidable public scourge causing worldwide mild to severe life-threatening infections. The ability of this strain to swiftly spread, evolve, and acquire resistance genes and virulence factors such as pvl genes has further rendered this strain difficult to treat. Of concern, is a recently recognized ability to resist antiseptic/disinfectant agents used as an essential part of treatment and infection control practices. This study aimed at detecting the presence of pvl genes and determining the distribution of antiseptic resistance genes in Methicillin-resistant Staphylococcus aureus isolates through whole genome sequencing technology. MATERIALS AND METHODS: A descriptive cross-sectional study was conducted across six regional referral hospitals-Dodoma, Songea, Kitete-Kigoma, Morogoro, and Tabora on the mainland, and Mnazi Mmoja from Zanzibar islands counterparts using the archived isolates of Staphylococcus aureus bacteria. The isolates were collected from Inpatients and Outpatients who attended these hospitals from January 2020 to Dec 2021. Bacterial analysis was carried out using classical microbiological techniques and whole genome sequencing (WGS) using the Illumina Nextseq 550 sequencer platform. Several bioinformatic tools were used, KmerFinder 3.2 was used for species identification, MLST 2.0 tool was used for Multilocus Sequence Typing and SCCmecFinder 1.2 was used for SCCmec typing. Virulence genes were detected using virulenceFinder 2.0, while resistance genes were detected by ResFinder 4.1, and phylogenetic relatedness was determined by CSI Phylogeny 1.4 tools. RESULTS: Out of the 80 MRSA isolates analyzed, 11 (14%) were found to harbor LukS-PV and LukF-PV, pvl-encoding genes in their genome; therefore pvl-positive MRSA. The majority (82%) of the MRSA isolates bearing pvl genes were also found to exhibit the antiseptic/disinfectant genes in their genome. Moreover, all (80) sequenced MRSA isolates were found to harbor SCCmec type IV subtype 2B&5. The isolates exhibited 4 different sequence types, ST8, ST88, ST789 and ST121. Notably, the predominant sequence type among the isolates was ST8 72 (90%). CONCLUSION: The notably high rate of antiseptic resistance particularly in the Methicillin-resistant S. aureus strains poses a significant challenge to infection control measures. The fact that some of these virulent strains harbor the LukS-PV and LukF-PV, the pvl encoding genes, highlight the importance of developing effective interventions to combat the spreading of these pathogenic bacterial strains. Certainly, strengthening antimicrobial resistance surveillance and stewardship will ultimately reduce the selection pressure, improve the patient's treatment outcome and public health in Tanzania.

Methicillin-Resistant Staphylococcus aureus↗

PubMed2026

α-Ketoglutarate Promotes Ciprofloxacin Tolerance in Methicillin-Resistant Staphylococcus aureus via Glutamate-Mediated Metabolic Remodeling.

Methicillin-resistant Staphylococcus aureus (MRSA) is a globally significant pathogen causing severe infections. The chronicity and recurrence of its infection pose serious challenges to public health. In this study, we reported that intracellular accumulation of α-ketoglutarate (α-KG) significantly increased ciprofloxacin (CIP) tolerance in MRSA. Using integrated metabolomic and functional genomic approaches, we demonstrated that both exogenous α-KG and genetic knockout of α-KG dehydrogenase (ΔsucA, ΔsucB) induced CIP tolerance in MRSA. Mechanistically, elevated α-KG levels drive the accumulation of glutamate (Glu), which in turn reduced bacterial membrane potential and cellular ATP content. Furthermore, Glu accumulation raised intracellular osmotic pressure, leading to decreased CIP uptake. These metabolic alterations enable MRSA to sustain high tolerance toward ciprofloxacin. Our findings reveal a key role of the α-KG-Glu metabolic axis in driving antibiotic tolerance and provide novel insights into the metabolic adaptations underlying drug persistence in MRSA.

Ciprofloxacin↗

PubMed1992

Staphylococcus aureus bacteremia in patients with hematologic disorders.

During the 20-year period, 1972-1991, 27 episodes of Staphylococcus aureus bacteremia, including 10 with methicillin-resistant strains (MRSA), were documented in 26 patients with hematologic disorders, mainly acute leukemia and malignant lymphoma, representing 6% of all 433 episodes of bacteremia in a hematology unit. MRSA replaced methicillin-sensitive strains (MSSA) in the last four years. The skin and upper respiratory tract were the two most common primary foci. Most episodes occurred during neutropenia. Pharyngeal colonization often preceded the development of bacteremia. Antibiotic therapy predisposed to MRSA acquisition during hospitalization, whereas MSSA was mostly detected in admission cultures. Among 22 patients with monomicrobial bacteremia, 19 (86%) survived longer than one week, including all four with MRSA bacteremia who received vancomycin. The survival rate did not differ materially between MRSA and MSSA bacteremias. Secondary foci, chiefly located in the lung, were found in 30% of all patients with S. aureus bacteremia. Prolonged antibiotic therapy, therefore, seems warranted in patients with evident metastatic lesions, although abbreviated therapy is proposed in neutropenic cancer patients.

Adolescent↗

PubMed2026

Detachable dissolving microneedles loaded with Silviavirus phage Pelagios enhance antibacterial efficacy against methicillin resistant Staphylococcus aureus in ex vivo porcine skin.

Methicillin-resistant Staphylococcus aureus (MRSA) wound infections remain a major clinical challenge due to antibiotic resistance and biofilm persistence. Although phage therapy has re-emerged as a promising alternative, its efficacy is limited by poor stratum corneum penetration following conventional topical application. Here, we isolated and characterized a lytic MRSA phage, Pelagios, and evaluated its transdermal delivery using detachable dissolvable microneedles (DDMNs). Genomic analyses classified Pelagios within the genus Silviavirus of the family Herelleviridae and indicated that it may represent a novel species. The phage displayed rapid adsorption (∼15 min), a short latent period (∼20 min), a burst size of ∼102 PFU/cell, and stability across physiologically relevant temperature (4 °C -45 °C) and pH conditions (pH 4-10). Whole-genome sequencing confirmed the absence of toxin genes, virulence factors, antimicrobial resistance determinants, and lysogeny-associated genes, supporting its genomic safety. Pelagios exhibited broad lytic activity against multiple clinical MRSA isolates and significantly reduced planktonic bacterial populations both in vitro and in ex vivo porcine skin models in a dose-independent manner. It also effectively inhibited MRSA biofilm formation, although eradication of established biofilms was limited. Phage-loaded DDMNs fabricated from hyaluronic acid and gelatin achieved efficient skin penetration, rapid dissolution, complete needle detachment, and markedly improved phage stability at 4 °C. In ex vivo infection models, DDMN-mediated delivery significantly enhanced antibacterial and biofilm-eradicating efficacy compared with free phage suspension. These findings demonstrate that Pelagios delivered via DDMNs constitutes a safe and effective strategy for treating MRSA-associated wound and biofilm infections.

Staphylococcus aureus↗

PubMed1992

Methicillin-resistant Staphylococcus aureus in England and Wales.

Methicillin-resistant Staphylococcus aureus (MRSA) were detected soon after the introduction of methicillin in 1960, and reports of their isolation increased up to 1971. Changes in antibiotic usage were associated with a fall and then, in the early 1980s, a further rise in the number of reports. This article reviews the various surveys that have been conducted to establish the frequency, distribution and strain varieties of MRSA. The first strain to be recognised as epidemic (ie, affecting more than one hospital), was defined by phage typing and antibiogram, confirmed with molecular typing, and designated EMRSA-1. It was first detected in 1981 and became progressively more widespread until it began to decline in 1987. Only three health regions reported this strain in the first quarter of 1991. EMRSA-2 has remained restricted to the South East and South West Thames regions. EMRSA-3 appeared in the South East Thames region in 1987 and has since spread, being reported from eight health regions in the first quarter of 1991. At least 11 other strains of MRSA affecting more than one hospital have been detected and ten endemic strains (restricted to single hospitals) have been identified. Imported strains of MRSA, often introduced following the repatriation of road traffic accident victims, may include strains with epidemic potential and local spread has followed importation in at least two incidents. Continued surveillance of epidemic MRSA strains and the search for simple and widely applicable markers, such as unusual antibiotic resistance patterns or biochemical features, are needed for the prompt application of control measures.

Aged↗

PubMed2026

Nasopharyngeal Carriage Rate, Risk Factors, and Co-Resistance Patterns of Methicillin-Resistant Staphylococcus aureus in Ethiopia: Systematic Review and Meta-Analysis.

Methicillin-resistant Staphylococcus aureus (MRSA) nasopharyngeal carriage is a major global health concern linked to severe infections and transmission. However, comprehensive evidence on the burden of MRSA carriage, antimicrobial resistance, and associated risk factors in Ethiopia remains limited. This study aimed to estimate pooled prevalence, resistance pattern, and determinants of nasopharyngeal MRSA carriage. PubMed, ScienceDirect, Scopus, Web of Science, Google Scholar, and gray literature were searched for cross-sectional studies published between January 2015 and December 2025. Two groups of reviewers screened studies based on predefined criteria. The risk of bias was assessed using the Joanna Briggs Institute tool. Pooled prevalence and resistance proportions were estimated using a random-effects model, and pooled odds ratios (ORs) were calculated using the Mantel-Haenszel method. Heterogeneity and publication bias were assessed, and a sensitivity analysis was conducted. A total of 1040 records were identified, and 20 studies (6869 participants) were included. The pooled carriage prevalence was 7.3% (95% CI, 5.0-10.8), with substantial heterogeneity (I2 = 95.5%). Resistance was highest to tetracycline (55.75%) and lowest to clindamycin (12.66%). Increased odds of carriage were associated with prior hospitalization (OR, 3.49) and antibiotic use (OR, 2.35). Inconsistent variable coding across included studies limited the inclusion of other potential risk factors. Evidence of publication bias was detected, suggesting that the pooled prevalence should be interpreted with appropriate caution. The findings indicate a considerable burden of MRSA and highlight the need for strengthened antimicrobial stewardship, improved surveillance, and targeted prevention efforts in higher-risk populations. This review was registered in PROSPERO (CRD420251047192).

Ethiopia↗

PubMed1992

[Epidemiological study of Staphylococcus aureus isolated from the Japanese National University and Medical College Hospitals with coagulase typing, and production of enterotoxins and toxic shock syndrome toxin-1].

Coagulase typing, staphylococcus enterotoxins (SE) A to E or toxic shock syndrome toxin-1 (TSST = 1) production, and susceptibility to Oxacillin (MPIPC) were examined in 430 strains of S. aureus, which were isolated from clinical specimen of 43 Japanese National University or Medical College Hospitals during the one month period of August in 1990. Methicillin-resistant Staphylococcus aureus (MRSA): more than 4 mmg/ml of minimum inhibitory concentration for MPIPC in Mueller-Hinton broth containing 2% NaCl, occupied 58.6% of all the S. aureus, and more than 60% of the strains from admitted patients in all the areas of Japan except Hokkaidoh. Coagulase type II, SEC and TSST-1 producing strains were most frequently detected, 34.5% of all the MRSA. This kind of strain was distributed mainly in the eastern part of the Honshyu island, and showed high percentage especially in the Tohhoku and the Chyubu area. The second most frequent kind of MRSA was coagulase type II, no SE nor TSST-1 producing one, 15.4%, which was distributed mainly in the western part of Japan. Coagulase type IV, SEA producing MRSA strains and Coagulase type II, SEA, SEC and TSST-1 producing strains were detected in relatively high incidence, 10.3% and 8.7% respectively. Coagulase type III, no SE nor TSST-1 producing MRSAs demonstrated characteristic distribution, and were detected only in the western part of Japan, presenting the highest incidence in the Shikoku Island.

Bacterial Toxins↗

PubMed1979

Methicillin potentiates the effect of gentamicin on methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) strains show an unusual type of resistance at 37 degrees C; only a small subpopulation of cells is resistant to the beta-lactam antibiotics. Incubation in the presence of methicillin (MET), however, results in the emergence of a homogenous population highly resistant to MET. The purpose of the present study was to determine whether MET, despite its lack of killing effect on MRSA, would promote the bactericidal effect of gentamicin (GM), as demonstrated for MET-susceptible strains of S. aureus. Eleven epidemiologically distinct strains of MRSA were incubated with MET at various concentrations, in the presence or absence of sub-bactericidal concentrations (1/5 or 1/10 of the minimal bactericidal concentration) of GM, and tested for the synergistic action of both antibiotics by three different methods. Population analysis of the 11 strains in the presence of high concentrations of MET showed that the addition of GM at 1/5 or 1/10 of its minimal bactericidal concentration resulted in marked killing of the 11 strains. Time-kill curves obtained with 32 mug of MET per ml and GM at 1/5 or 1/10 of its minimal bactericidal concentration confirmed this synergistic killing at 24 h. These results were further documented by the checkerboard method on two strains. We conclude that the synergism between MET and GM, previously demonstrated for MET-susceptible S. aureus, holds true for MRSA as well and that it can be demonstrated at sub-bactericidal concentrations of GM.

Drug Synergism↗

PubMed2026

A comparative analysis of the clinical and genomic characteristics of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus in Korea and Japan.

Panton-Valentine leukocidin (PVL) is a leukocyte-lytic toxin produced by Staphylococcus aureus, which is primarily associated with skin and soft tissue infections. Notably, there has been an increase in the number of cases caused by the USA300 lineage in Japan. However, the reported prevalence of USA300 is limited in other Asian countries, including Korea. This study investigated the prevalence of PVL-positive methicillin-resistant S. aureus (MRSA) in Korea and Japan and compared their molecular epidemiological characteristics. A total of 463 MRSA strains were analyzed, comprising 283 strains from patients visiting two hospitals in Seongnam and Seoul, Korea, and 180 strains from six hospitals in Tokyo, Japan, between 2018 and 2019. The PVL-encoding genes lukS/F-PV were detected using PCR. Molecular epidemiological and phylogenetic analyses were performed using next-generation sequencing. Overall, 27 (9.5%) PVL-positive MRSA strains were detected among strains isolated from Korea, and 16 (8.9%) were detected among those isolated from Japan. Genotyping of PVL-positive strains revealed that 85.2% of Korean and 81.3% of Japanese strains belonged to USA300. Most USA300 strains from Japan and Korea formed distinct clusters in phylogenetic analyses. Meanwhile, ΨUSA300 and ST22-PT, clones that are prevalent in Japan, were isolated in Korea. This study showed that USA300 strains, which are becoming more prevalent in Japan, are also present in Korea. Furthermore, this study suggests that ΨUSA300 and ST22-PT may be spreading between these two countries. Therefore, it is necessary to continue monitoring the epidemiological trends of PVL-positive MRSA clones both domestically and internationally.IMPORTANCEPanton-Valentine leukocidin (PVL) is a major toxin produced by Staphylococcus aureus. Although a rapid increase in PVL-positive strains has been reported in Japan, data on PVL-positive strains in Korea remain limited. In this study, we performed a comparative analysis of PVL-positive S. aureus isolates from Korea and Japan. The results showed that the clinical backgrounds and genetic profiles of PVL-positive strains isolated in Korea and Japan were highly similar. Furthermore, we confirmed for the first time that clones circulating in Japan, including ΨUSA300 and ST22-PT, were also isolated in Korea. These findings provide valuable insights into the epidemiological status of PVL-positive S. aureus in East Asia.

Leukocidins↗

PubMed2026

Hospital transmission of methicillin-resistant Staphylococcus aureus driven by addictive mupA plasmids.

BACKGROUND: Resistance to mupirocin, a cornerstone of Staphylococcus aureus decolonization, is a recognized cause of decolonization failure. Its role in hospital transmission is unknown. METHODS: We conducted genomic surveillance of >10,000 S. aureus isolates from adult patients at two urban hospitals where mupirocin decolonization is routine. Bacterial phenotypes and fitness were evaluated in vitro and in murine colonization models to interpret surveillance results. RESULTS: Genome sequencing identified 475 hospital transmission events; conventional surveillance detected none. The plasmid-mediated resistance determinant mupA ( ileS2 ) was enriched eightfold in methicillin-resistant S. aureus (MRSA) relative to methicillin-susceptible strains. mupA was associated with nearly threefold greater hospital transmission, especially within healthcare-associated MRSA lineages. Surprisingly, multiple independently evolved inactivating mutations in the essential chromosomal gene ileS1 co-occurred with mupA , creating plasmid addiction in which mupA became indispensable for bacterial survival. Plasmid carriage activated the stringent response and reduced colonization fitness, but also conferred collateral tolerance to disinfectants such as ethanol and peroxide. Although addiction further reduced S. aureus fitness, it increased plasmid transfer, promoting spread despite these costs. Unexpectedly, we found a mupirocin-dependent vulnerability to isoleucine limitation, revealing a potential strategy to target mupA -mediated resistance. CONCLUSIONS: Hospital transmission of mupirocin-resistant MRSA is promoted by plasmids that create an evolutionary trap in which mupirocin use selects for bacterial dependence on costly resistance elements. These findings suggest that reducing mupirocin use alone is unlikely to eliminate resistance, underscore the need for genomic surveillance and resistance testing, and provide a framework for strategies to preserve mupirocin effectiveness. MAJOR POINT: This work shows that mupirocin resistance promotes hospital transmission of MRSA, identifies a previously unappreciated mechanism of plasmid addiction, and exposes a collateral vulnerability. These findings underscore the need for genomic surveillance and provide a framework to preserve mupirocin effectiveness.

Journal Article↗

PubMed2023

Teicoplanin associated gene tcaA inactivation increases persister cell formation in Staphylococcus aureus.

Staphylococcus aureus is part of normal human flora and is widely associated with hospital-acquired bacteremia. S. aureus has shown a diverse array of resistance to environmental stresses and antibiotics. Methicillin-resistant S. aureus (MRSA) is on the high priority list of new antibiotics discovery and glycopeptides are considered the last drug of choice against MRSA. S. aureus has developed resistance against glycopeptides and the emergence of vancomycin-intermediate-resistant, vancomycin-resistant, and teicoplanin-resistant strains is globally reported. Teicoplanin-associated genes tcaR-tcaA-tcaB (tcaRAB) is known as the S. aureus glycopeptide resistance operon that is associated with glycopeptide resistance. Here, for the first time, the role of tcaRAB in S. aureus persister cells formation, and ΔtcaA dependent persisters' ability to resuscitate the bacterial population was explored. We recovered a clinical strain of MRSA from a COVID-19 patient which showed a high level of resistance to teicoplanin, vancomycin, and methicillin. Whole genome RNA sequencing revealed that the tcaRAB operon expression was altered followed by high expression of glyS and sgtB. The RNA-seq data revealed a significant decrease in tcaA (p = 0.008) and tcaB (p = 0.04) expression while tcaR was not significantly altered. We knocked down tcaA, tcaB, and tcaR using CRISPR-dCas9 and the results showed that when tcaA was suppressed by dCas9, a significant increase was witnessed in persister cells while tcaB suppression did not induce persistence. The results were further evaluated by creating a tcaA mutant that showed ΔtcaA formed a significant increase in persisters in comparison to the wild type. Based on our findings, we concluded that tcaA is the gene that increases persister cells and glycopeptide resistance and could be a potential therapeutic target in S. aureus.

MRSA↗

PubMed1992

Development of new antibiotic resistance in methicillin-resistant but not methicillin-susceptible Staphylococcus aureus.

The frequency of infections caused by multidrug-resistant Staphylococcus aureus continues to increase while the numbers of alternative therapeutic agents remain limited. To investigate the changing patterns of in-vitro susceptibility of S. aureus to 16 antibiotics, 190 clinical isolates from two different years were studied. The MICs of methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains isolated in 1987 were compared with those of similar numbers of strains isolated in 1989. For MRSA > or = 90% of isolates from both years were resistant to clindamycin, gentamicin and erythromycin. These strains remained highly susceptible to vancomycin (100%), minocycline (90%) and rifampicin (100%). The greatest increase in resistance was observed for ofloxacin (2% in 1987 vs 62% in 1989); cross-resistance to all of the quinolones tested was demonstrated. MSSA strains remained susceptible to vancomycin (100%), minocycline (98%), rifampicin (100%), clindamycin (90%), gentamicin (90%) and ciprofloxacin (98%). It is concluded that methicillin susceptibility is a useful marker for selecting potential agents for the treatment of infections caused by S. aureus. A combination of minocycline and rifampicin may be a useful alternative to vancomycin for treating MRSA infections.

Drug Resistance, Microbial↗

PubMed2025

Antimicrobial resistance among Gram-positive agents of bacteraemia in the UK and Ireland: trends from 2001 to 2019.

OBJECTIVES: The BSAC Bacteraemia Resistance Surveillance collected isolates from UK and Irish hospitals for central testing. Concurrent UKHSA surveillance collated English hospitals' own susceptibility data. Results were collated and compared. METHODS: BSAC Surveillance collected quotas of isolates per site annually from 2001 to 2019. MIC testing was by BSAC agar dilution, with resistance mechanisms identified by synergy tests, interpretive reading and PCR. The UKHSA sought hospitals' data on all bacteraemia isolates. RESULTS: Both surveillance systems recorded dramatic falls in MRSA, from c. 40% of bloodstream Staphylococcus aureus in 2001 to <10% by 2019. Both noted rises in the proportion of MRSA (especially) and MSSA resistant to fusidic acid, along with declines of ciprofloxacin and macrolide resistance amongst MRSA. Methicillin resistance also fell among coagulase-negative staphylococci, albeit only modestly; fusidic acid resistance rose. Shifts for pneumococci were complex, reflecting vaccine-contingent serotype displacements; resistance rates remained low, with high-dose penicillin almost universally active. Enterococcus faecium became more prevalent relative to Enterococcus faecalis; vancomycin resistance averaged 29% among E. faecium versus 2% in E. faecalis, without trend. Erythromycin resistance rose among groups B, C and G (but not group A) streptococci. Oxazolidinones, tigecycline, daptomycin and anti-PBP2' cephalosporins retained near-universal activity against target species, except that tigecycline has been compromised by breakpoint reductions for streptococci. CONCLUSIONS: Gram-positive pathogens were the dominant historical pathogens of bacteraemia. The trends seen here-with many near-universally active antibiotics-indicate little hazard of this situation returning. Nevertheless, few treatments exist in some settings, notably multi-resistant E. faecium endocarditis.

Humans↗

PubMed2026

Antimicrobial-resistant Staphylococcus aureus isolated from Australian wildlife admitted to a veterinary hospital.

Although antimicrobial resistance (AMR) is a growing One Health concern, little is known about AMR in Staphylococcus aureus from Australian wildlife. This study investigated the occurrence, phenotypic AMR profiles, and genetic characteristics of S. aureus from six representative Australian wildlife species admitted to a wildlife hospital in Western Australia, including the western grey kangaroo (Macropus fuliginosus), quenda (Isoodon fusciventer), pelican (Pelecanus conspicillatus), galah (Eolophus roseicapilla), shingleback skink (Tiliqua rugosa) and long-necked turtle (Chelodina colliei). Staphylococcus aureus was isolated from 11.7% (21/180, 95% CI: 7.4%-17.3%) of the animals on admission. Whole genome sequencing identified 13 multi-locus sequence types (STs) and various virulence factors, including the human-specific immune evasion cluster (IEC). Resistance to at least one antimicrobial class was observed in 63.6% of the isolates. The blaZ, erm(T), aac(6')-aph(2″), and tet(L) AMR genes were detected in 63.6%, 13.6%, 4.5%, and 4.5% of S. aureus, respectively. After 7 days of hospitalisation, S. aureus was isolated from 16.5% (16/97, 95% CI: 9.7%-25.4%) of the animals, including two methicillin-resistant S. aureus (MRSA) isolated from two pelicans. The two MRSA were identified as community-associated MRSA clones (mecA-positive ST1-IV and ST93-IV), suggesting direct or indirect transmission between humans and wildlife during hospitalisation may have occurred. This study highlighted Australian wildlife may be a potential reservoir for genetically diverse antimicrobial-resistant S. aureus. AMR surveillance including wildlife using a One Health approach may be required.

Animals↗

PubMed1992

[A case of staphylococcal enterocolitis caused by methicillin resistant Staphylococcus aureus].

Recently, the frequency of methicillin resistant Staphylococcus aureus (MRSA) infection has been increasing. We experienced a case of postoperative enterocolitis due to MRSA. The patient was an 81-year-old male with benign prostatic hypertrophy. Urine leakage from the penrose drain tube appeared 1 day after suprapubic prostatectomy. We had used intravenous infusion of antibiotic agents including cefodizine (CDZM), imipenem (IPM/CS) and cefmetazol (CMZ). He developed severe diarrhea, high fever, oliguria, leg edema and ascites 24 days after the operation. MRSA was detected from his feces. Toxic shock syndrome toxin-I (TSST-I) was produced by this bacteria the coagulase type of which was type II. The patient was treated with oral vancomycin (1 g/day), to which this bacteria showed sensitivity and the patient showed, improvement, including symptoms, leucocytosis and serum CRP level 12 days after administration of vancomycin.

Administration, Oral↗

PubMed2026

Comparative Genomics of Paenibacillus Secondary Metabolism: Unveiling the Putative Biosynthetic Gene Cluster for Paenialvins in Paenibacillus Alvei Strain 32.

In this study, we used comparative genomics and culture-based methods to investigate Biosynthetic Gene Clusters (BGCs) responsible for the production of antimicrobial peptides. Paenibacillus alvei strain 32 was isolated from a cystic fibrosis sputum. Its genome was sequenced using Illumina, showing a size of 6,584,590 bp with 239 contigs assembled in 26 scaffolds, an average coverage of 243X, and 6,832 coding sequences. ANI analysis and in silico DNA-DNA hybridization showed its affiliation inside Paenibacillus alvei, with a clear separation from other related strains, leading us to propose a distinct species-level genomic clade (genomospecies) within this group. AntiSMASH analysis predicted 22 putative BGCs in the genome of strain 32. Its culture supernatant exhibited inhibitory activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), Bacillus cereus, and Enterococcus faecalis. By comparing in silico BGC predictions with activities described in the literature, we propose that strain 32 harbours a specific 110-kb cluster (cluster 6.2) with five non-ribosomal peptide synthetase (NRPS) genes. These synthetases are predicted to direct the assembly of a 16-amino acid backbone that correlates with the structure of paenialvins, which are known anti-MRSA molecules. This study describes the putative biosynthetic pathway of the paenialvins and explains structural variations, bringing useful data on Paenibacillus secondary metabolism for future antibiotic development.

Paenibacillus alvei↗

PubMedDate not supplied

Carriage of methicillin-resistant Staphylococcus aureus by non-hospitalized subjects in Israel.

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the anterior nares and axilla was studied in 920 non-hospitalized subjects: 350 drug addicts, 350 individuals presenting at a hospital emergency room for various reasons, and 220 hospital health care workers. S. aureus was isolated from 105 (11.4%) subjects, in six (6.3%) of whom the isolates were methicillin-resistant. The isolation rate of the organism and the prevalence of resistant strains in the different subgroups were, respectively: drug-addicts, n = 32 (9.1%), n = 2 (6.9%); emergency room patients, n = 36 (10.2%), n = 1 (3.2%); and hospital health care workers, n = 37 (16.8%), n = 3 (8.5%). Our findings suggest that MRSA remains uncommon in the community, while the prevalence of S. aureus carriage (including methicillin-resistant strains) in hospital personnel is quite similar in divergent geographical areas.

Adult↗

PubMed2025

Universal versus targeted chlorhexidine and mupirocin decolonisation and clinical and molecular epidemiology of Staphylococcus epidermidis bloodstream infections in patients in intensive care in Scotland, UK: a controlled time-series and longitudinal genotypic study.

BACKGROUND: There are concerns that biocide skin and mucous membrane decolonisation, which is widely used to prevent health-care-associated infections in intensive care units (ICUs), might select for multidrug-resistant pathogens. We aimed to evaluate the effects of de-escalating from universal to targeted skin and nasal decolonisation on Staphylococcus epidermidis bloodstream infections (SE-BSI). METHODS: We did a retrospective, before-after-control-impact time-series analysis and longitudinal genotypic study in two ICUs with divergent decolonisation practice in tertiary care hospitals of adjacent health boards in Scotland, UK. Participants were aged at least 16 years and admitted between July 1, 2009, and Feb 28, 2022. There were no exclusion criteria for the study. In ICU one (intervention site) universal decolonisation in all admissions was de-escalated to targeted decolonisation of meticillin-resistant Staphylococcus aureus (MRSA) carriers on Feb 1, 2019, while in ICU two (control site) targeted decolonisation was applied throughout. We collected bloodstream infection data from all causes, including clinically significant SE-BSI. Antimicrobial susceptibility testing was used to define meticillin-resistant S epidermidis (MRSE) and chlorhexidine susceptibility. We used multilocus sequence typing to identify sequence types from archived SE-BSI isolates. Whole-genome sequencing was applied to a sample from ICU one. The primary outcomes were incidence densities of all bloodstream infections, SE-BSI, and meticillin-resistant S epidermidis bloodstream infections (MRSE-BSI), and the percentage probability that SE-BSI were MRSE-BSI. The effects of de-escalation on primary outcomes were estimated by differences between the intervention and control sites, before and after de-escalation, using a before-after-control-impact time-series design. Secondary outcomes included the proportion of multidrug resistant sequence types, carriage of mobile genetic elements and genes for multidrug resistance and biofilm production. FINDINGS: Between July 1, 2009, and Feb 28, 2022, S epidermidis was identified in 334 (45%) of 735 bloodstream infections in ICU one, of which 197 occurred before the de-escalation intervention in Feb 1, 2019, and S epidermidis was identified in 167 (60%) of 278 bloodstream infections in ICU two. There was no increase in all bloodstream infection incidence coinciding with de-escalation in ICU one, whereas MRSE-BSI incidence declined significantly from 10·4 cases per 1000 occupied bed days (OBDs; 95% credible interval [CrI] 7·2-15·4) to 4·3 cases per 1000 OBDs (2·5-6·7), as did the percentage probability of MRSE (from 89·2%, 95% CrI 77·8-96·5 to 56·7%, 34·3-77·5%). No significant changes in the primary outcomes were seen in ICU two. MRSE-BSI incidence density was positively associated with chlorhexidine use, but not mupirocin use. De-escalation was associated with a reduced proportion of SE-BSI due to multidrug-resistant sequence types and reduced carriage of mobile genetic elements and genes for multidrug resistance and biofilm production, as observed by multi-locus sequence typing and whole genome sequencing. INTERPRETATION: In ICU settings with low MRSA incidence, the benefits of universal decolonisation should be balanced against the risks of selecting MRSE sequence types adapted for invasive and device-associated infection. FUNDING: National Health Service Grampian Charity.

Humans↗