scholarly journals Increased Incidence and Plasma-Biofilm Formation Ability of SCCmec Type IV Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated From Patients With Bacteremia

Author(s):  
Masakaze Hamada ◽  
Tetsuo Yamaguchi ◽  
Ayami Sato ◽  
Daisuke Ono ◽  
Kotaro Aoki ◽  
...  

In Japan, Staphylococcal cassette chromosome mec (SCCmec) type IV methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly prominent cause of bacteremia, but the virulence of most of these strains is unclear. We aimed to investigate the relationship between the molecular characteristics and the ability to form biofilms in the presence of blood plasma (plasma-biofilms) of MRSA strains isolated from bloodstream infections. In this study, the molecular characteristics and biofilms of MRSA strains isolated from blood cultures between 2015 and 2017 were analyzed by PCR-based assays, crystal violet staining, and confocal reflection microscopy methods. Among the 90 MRSA isolates, the detection rate of SCCmec type II clones decreased from 60.7 to 20.6%. The SCCmec type IV clone replaced the SCCmec type II clone as the dominant clone, with a detection rate increasing from 32.1 to 73.5%. The plasma-biofilm formation ability of the SCCmec type IV clone was higher than the SCCmec type II clone and even higher in strains harboring the cna or arcA genes. Plasma-biofilms, mainly composed of proteins, were formed quickly and strongly. Our study demonstrated the increased plasma-biofilm formation ability of SCCmec type IV strains.

2021 ◽  
Author(s):  
Norihito Kaku ◽  
Daisuke Sasaki ◽  
Kenji Ota ◽  
Katsunori Yanagihara ◽  
Taiga Miyazaki

Objectives: Some single-center studies have reported that methicillin-resistant Staphylococcus aureus (MRSA) carrying the staphylococcal cassette chromosome mec (SCCmec) type IV has been increasing in bloodstream infections (BSIs) in Japan. Therefore, we conducted nationwide surveillance for MRSA BSI in Japan to verify that there is a change all over Japan. Methods: We recruited 51 Japanese hospitals from the Japanese Association for Infectious Diseases. MRSA strains, which were detected in two or more sets of blood, were collected between January and September 2019. They were analyzed by antimicrobial susceptibility testing at Nagasaki University Hospital. Whole-genome sequencing was also performed to determine SCCmec typing and multilocus typing and detect drug-resistance and virulence genes. Results: 270 MRSA strains were collected from 44 hospitals. The major clones were ST8 with SCCmec type IV (ST8-IV) (30.7%), ST1-IV (29.6%), ST2725-IV (9.5%), ST764-II (8.1%), and ST5-II (7.8%). However, there were regional differences among the most major clones. The most common clones in western, eastern, and northern Japan were ST1-IV, ST8-IV, and ST5-II, respectively. ST8-IV, ST1-IV, and ST2725-IV exhibited lower drug resistance against clindamycin and minocycline than ST764-II and ST5-II, but erm(A) was detected in 93.8% and 100% of ST1-IV and ST2725-IV, respectively. Based on drug-resistance and virulence genes, characteristics were different between ST8-IV and clonal complex 1-IV comprising ST1-IV and ST2725. In addition, the two major types were expected to be ST8-IV. Conclusions: This study revealed that SCCmec type IV clones replaced SCCmec type II in MRSA BSI.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S263-S263
Author(s):  
Hiroki Kitagawa ◽  
Junzo Hisatsune ◽  
Hiroki Ohge ◽  
Motoyuki Sugai

Abstract Background Recently, the Japanese intrinsic community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone (CA-MRSA/J), classified as sequence type (ST) 8 carrying staphylococcal cassette chromosome mec (SCCmec) type IVl (ST8-IVl), has been identified that causes invasive infections similar to those of USA300 clone. However, epidemiological information regarding epidemic CA-MRSA clones is limited in Japan. This study was performed to investigate the changing epidemiology of MRSA causing bacteremia in Japan. Methods We performed whole-genome sequencing of MRSA isolates causing bacteremia at Hiroshima University Hospital between January 2008 and December 2017. MRSA isolates were subjected to multilocus sequence typing, SCCmec typing and were analyzed for virulence factors. Clinical data of patients with MRSA bacteremia were analyzed. Results A total of 193 MRSA strains causing bacteremia were identified during the study period. Among these, most belonged to ST764-IIa (30%; 59 of 193) and ST5-IIa (26.9%; 52 of 193). The proportion of ST5-IIa MRSA decreased from 39.6% (42 of 106) in 2008–2012 to 11.5% (10 of 87) in 2013–2017, and that of ST764-IIa MRSA increased from 23.6% (25 of 106) to 39.1% (34 of 87) in the same time period. The proportion of CA-MRSA (MRSA carrying SCCmec type IV or V) increased from 28.3% (30 of 106) in 2008–2012 to 42.5% (37 of 87) in 2013–2017. In CA-MRSA strains, clonal complex (CC) 8-IV MRSA was predominant (76.1%; 51 of 67). Those belonging to CC8-IV MRSA isolates were ST380-IVc (18 of 51), ST8-IVl (CA-MRSA/J; 15 of 51), ST8-IVj (15 of 51), ST8-IVa (2 of 51), and ST4803-IVl (1 of 51). The rate of hospital-onset infections of ST380-IVc, ST8-IVl, and ST8-IVj were 83.3%, 46.7%, and 60%, respectively. In CA-MRSA/J strains, including their variants (e.g., ST4803-IVl), 14 of 16 strains (87.5%) carried genes for toxic shock syndrome toxin (tst-1), enterotoxin C (sec), and enterotoxin L (sel), while none of the ST380-IVc and ST8-IVj MRSA strains carried these genes. Conclusion During the study period of 10 years, predominant ST5-IIa MRSA causing hospital-onset infections was replaced by ST764-IIa MRSA. In CA-MRSA clone, ST380-IVc, ST8-IVl (CA-MRSA/J), and ST8-IVj were dominant and have already spread to the healthcare environment. Disclosures All authors: No reported disclosures.


2010 ◽  
Vol 76 (15) ◽  
pp. 5165-5174 ◽  
Author(s):  
Kanako Ishihara ◽  
Natsumi Shimokubo ◽  
Akie Sakagami ◽  
Hiroshi Ueno ◽  
Yasukazu Muramatsu ◽  
...  

ABSTRACT Recently, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP) have been increasingly isolated from veterinarians and companion animals. With a view to preventing the spread of MRSA and MRSP, we evaluated the occurrence and molecular characteristics of each in a veterinary college. MRSA and MRSP were isolated from nasal samples from veterinarians, staff members, and veterinary students affiliated with a veterinary hospital. Using stepwise logistic regression, we identified two factors associated with MRSA carriage: (i) contact with an identified animal MRSA case (odds ratio [OR], 6.9; 95% confidence interval [95% CI], 2.2 to 21.6) and (ii) being an employee (OR, 6.2; 95% CI, 2.0 to 19.4). The majority of MRSA isolates obtained from individuals affiliated with the veterinary hospital and dog patients harbored spa type t002 and a type II staphylococcal cassette chromosome mec (SCCmec), similar to the hospital-acquired MRSA isolates in Japan. MRSA isolates harboring spa type t008 and a type IV SCCmec were obtained from one veterinarian on three different sampling occasions and also from dog patients. MRSA carriers can also be a source of MRSA infection in animals. The majority of MRSP isolates (85.2%) carried hybrid SCCmec type II-III, and almost all the remaining MRSP isolates (11.1%) carried SCCmec type V. MRSA and MRSP were also isolated from environmental samples collected from the veterinary hospital (5.1% and 6.4%, respectively). The application of certain disinfection procedures is important for the prevention of nosocomial infection, and MRSA and MRSP infection control strategies should be adopted in veterinary medical practice.


2007 ◽  
Vol 28 (10) ◽  
pp. 1206-1209 ◽  
Author(s):  
D. Neofytos ◽  
B. Kuhn ◽  
S. Shen ◽  
X. Hua Zhu ◽  
D. Jungkind ◽  
...  

Staphylococcal cassette chromosomemec(SCCmec) type IV methicillin-resistantStaphylococcus aureus(MRSA) strains were identified in 8 (19.5%) of 41 consecutive patients with MRSA ventilator-associated pneumonia (VAP) in this retrospective, observational study. There were no significant differences in VAP severity and crude mortality rates between patients with SCCmectype II strains and patients with SCCmectype IV strains.


Toxins ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 14
Author(s):  
Thamiris Santana Machado ◽  
Felipe Ramos Pinheiro ◽  
Lialyz Soares Pereira Andre ◽  
Renata Freire Alves Pereira ◽  
Reginaldo Fernandes Correa ◽  
...  

Hospitalizations related to Methicillin-resistant Staphylococcus aureus (MRSA) are frequent, increasing mortality and health costs. In this way, this study aimed to compare the genotypic and phenotypic characteristics of MRSA isolates that colonize and infect patients seen at two hospitals in the city of Niterói—Rio de Janeiro, Brazil. A total of 147 samples collected between March 2013 and December 2015 were phenotyped and genotyped to identify the protein A (SPA) gene, the mec staphylococcal chromosomal cassette (SCCmec), mecA, Panton-Valentine Leucocidin (PVL), icaC, icaR, ACME, and hla virulence genes. The strength of biofilm formation has also been exploited. The prevalence of SCCmec type IV (77.1%) was observed in the colonization group; however, in the invasive infection group, SCCmec type II was prevalent (62.9%). The Multilocus Sequence Typing (MLST), ST5/ST30, and ST5/ST239 analyses were the most frequent clones in colonization, and invasive infection isolates, respectively. Among the isolates selected to assess the ability to form a biofilm, 51.06% were classified as strong biofilm builders. Surprisingly, we observed that isolates other than the Brazilian Epidemic Clone (BEC) have appeared in Brazilian hospitals. The virulence profile has changed among these isolates since the ACME type I and II genes were also identified in this collection.


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 395
Author(s):  
Katarina Pomorska ◽  
Vladislav Jakubu ◽  
Lucia Malisova ◽  
Marta Fridrichova ◽  
Martin Musilek ◽  
...  

Staphylococcus aureus is one of the major causes of bloodstream infections. The aim of our study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates from blood of patients hospitalized in the Czech Republic between 2016 and 2018. All MRSA strains were tested for antibiotic susceptibility, analyzed by spa typing and clustered using a Based Upon Repeat Pattern (BURP) algorithm. The representative isolates of the four most common spa types and representative isolates of all spa clonal complexes were further typed by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The majority of MRSA strains were resistant to ciprofloxacin (94%), erythromycin (95.5%) and clindamycin (95.6%). Among the 618 strains analyzed, 52 different spa types were detected. BURP analysis divided them into six different clusters. The most common spa types were t003, t586, t014 and t002, all belonging to the CC5 (clonal complex). CC5 was the most abundant MLST CC of our study, comprising of 91.7% (n = 565) of spa-typeable isolates. Other CCs present in our study were CC398, CC22, CC8, CC45 and CC97. To our knowledge, this is the biggest nationwide study aimed at typing MRSA blood isolates from the Czech Republic.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 430
Author(s):  
Wichai Santimaleeworagun ◽  
Praewdow Preechachuawong ◽  
Wandee Samret ◽  
Tossawan Jitwasinkul

Methicillin-resistant Staphylococcus aureus (MRSA) is mostly found in Thailand in the hospital as a nosocomial pathogen. This study aimed to report the genetic characterization of a clinical community-acquired MRSA (CA-MRSA) isolate collected from hospitalized patients in Thailand. Among 26 MRSA isolates, S. aureus no. S17 preliminarily displayed the presence of a staphylococcal cassette chromosome mec (SCCmec) type IV pattern. The bacterial genomic DNA was subjected to whole-genome sequencing. Panton–Valentine leukocidin (PVL) production, virulence toxins, and antibiotic resistance genes were identified, and multi-locus sequence typing (MLST) and spa typing were performed. The strain was matched by sequence to MLST type 2885 and spa type t13880. This strain carried type IV SCCmec with no PVL production. Five acquired antimicrobial resistance genes, namely blaZ, mecA, Inu(A), tet(K), and dfrG conferring resistance to β-lactams, lincosamides, tetracycline, and trimethoprim, were identified. The detected toxins were exfoliative toxin A, gamma-hemolysin, leukocidin D, and leukocidin E. Moreover, there were differences in seven regions in CR-MRSA no. S17 compared to CA-MRSA type 300. In summary, we have reported the ST2885-SCCmec IV CA-MRSA clinical strain in Thailand for the first time, highlighting the problem of methicillin resistance in community settings and the consideration in choosing appropriate antibiotic therapy.


2015 ◽  
Vol 59 (8) ◽  
pp. 4497-4503 ◽  
Author(s):  
Katie E. Barber ◽  
Jordan R. Smith ◽  
Cortney E. Ireland ◽  
Blaise R. Boles ◽  
Warren E. Rose ◽  
...  

ABSTRACTAnnually, medical device infections are associated with >250,000 catheter-associated bloodstream infections (CLABSI), with up to 25% mortality.Staphylococcus aureus, a primary pathogen in these infections, is capable of biofilm production, allowing organism persistence in harsh environments, offering antimicrobial protection. With increases inS. aureusisolates with reduced susceptibility to current agents, ceftaroline (CPT) offers a therapeutic alternative. Therefore, we evaluated whether CPT would have a role against biofilm-producing methicillin-resistantS. aureus(MRSA), including those with decreased susceptibilities to alternative agents. In this study, we investigated CPT activity alone or combined with daptomycin (DAP) or rifampin (RIF) against 3 clinical biofilm-producing MRSA strains in anin vitrobiofilm pharmacokinetic/pharmacodynamic (PK/PD) model. Simulated antimicrobial regimens were as follows: 600 mg of CPT every 8 h (q8h) (free maximum concentration of drug [fCmax], 17.04 mg/liter; elimination half-life [t1/2], 2.66 h), 12 mg/kg of body weight/day of DAP (fCmax, 14.7 mg/liter;t1/2, 8 h), and 450 mg of RIF q12h (fCmax, 3.5 mg/liter;t1/2, 3.4 h), CPT plus DAP, and CPT plus RIF. Samples were obtained and plated to determine colony counts. Differences in log10CFU/cm2were evaluated by analysis of variance with Tukey'spost hoctest. The strains were CPT and vancomycin susceptible and DAP nonsusceptible (DNS). CPT displayed activity throughout the experiment. DAP demonstrated initial activity with regrowth at 24 h in all strains. RIF was comparable to the drug-free control, and little benefit was observed when combined with CPT. CPT plus DAP displayed potent activity, with an average log10CFU/cm2reduction of 3.33 ± 1.01 from baseline. CPT demonstrated activity against biofilm-producing DNS MRSA. CPT plus DAP displayed therapeutic enhancement over monotherapy, providing a potential option for difficult-to-treat medical device infections.


Sign in / Sign up

Export Citation Format

Share Document