scholarly journals Nationwide surveillance of methicillin-resistant Staphylococcus aureus isolated from bloodstream infections in Japan

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.


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.


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.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Debadatta Dhar Chanda ◽  
Amitabha Bhattacharjee

Abstract Objective This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical, community and environmental settings. Results This study includes 1165 isolates collected from hospital, community and environmental settings. Among them sixty three were confirmed as MRSA with varied SCCmec types viz; type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII. The virulence gene such as sea (n = 54), seb (n = 21), eta (n = 27), etb (n = 2), cna (n = 24), ica (n = 2) and tst (n = 30) was also revealed from this study. The study underscores coexistence of resistance cassette and virulence genes among clinical and environment isolates which is first of its kind from this part of the world.


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.


2020 ◽  
Author(s):  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Debadatta Dhar Chanda ◽  
Amitabha Bhattacharjee

Abstract Objective: This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical and environmental settings. Results: The virulence gene such as sea (n=54), seb (n=21), eta (n=27), etb (n=2), cna (n=24), ica (n=2) and tst (n=30) was revealed from this study. Different SCCmec types such as type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII were detected among sixty three MRSA isolates where SCCmec type II having ST1551 and type V with ST2416 were found to be associated with multidrug resistance and were highly prevalent in the study area.


2019 ◽  
Vol 8 (6) ◽  
pp. 816 ◽  
Author(s):  
Kuo-Ti Peng ◽  
Tsung-Yu Huang ◽  
Yao-Chang Chiang ◽  
Yu-Yi Hsu ◽  
Fang-Yi Chuang ◽  
...  

Methicillin-resistant Staphylococcus aureus (MRSA) causes superficial infections such as cellulitis or invasive infections such as osteomyelitis; however, differences in MRSA isolates from cellulitis (CL-MRSA) and from osteomyelitis (OM-MRSA) at the same local area remain largely unknown. A total of 221 MRSA isolates including 106 CL-MRSA strains and 115 OM-MRSA strains were collected at Chang-Gung Memorial Hospital in Taiwan between 2016 and 2018, and their genotypic and phenotypic characteristics were compared. We found that OM-MRSA isolates significantly exhibited higher rates of resistance to multiple antibiotics than CL-MRSA isolates. Genotypically, OM-MRSA isolates had higher proportions of the SCCmec type III, the sequence type ST239, and the spa type t037 than CL-MRSA isolates. Besides the multidrug-resistant lineage ST239-t037-SCCmecIII more prevalent in OM-MRSA, higher antibiotic resistance rates were also observed in several other prevalent lineages in OM-MRSA as compared to the same lineages in CL-MRSA. Furthermore, when prosthetic joint infection (PJI) associated and non-PJI-associated MRSA strains in osteomyelitis were compared, no significant differences were observed in antibiotic resistance rates between the two groups, albeit more diverse genotypes were found in non-PJI-associated MRSA. Our findings therefore suggest that deep infections may allow MRSA to evade antibiotic attack and facilitate the convergent evolution and selection of multidrug-resistant lineages.


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