scholarly journals Methicillin-resistant Staphylococcus aureus of the clonal lineage ST5-SCCmecII-t2460 was associated with high mortality in a Wuhan hospital

2021 ◽  
Author(s):  
Xuehan Li ◽  
Jing Zhang ◽  
Yifan Zhang ◽  
Junying Zhou ◽  
Xinwei Li ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
White Blood Cells ◽  
Resistance Rate ◽  
Molecular Characteristics ◽  
Invasive Procedures ◽  
Methicillin Resistant ◽  
Small Colony Variant ◽  
Recent Emergence ◽  
Resistance Rates

AbstractMethicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that can cause serious infectious diseases. An emerging MRSA strain, ST5-SCCmecII spa-type-t2460 (SMRSA), has spread rapidly since its recent emergence in China, but little information is available about this lineage. In this study, 91 MRSA isolates were collected from patients treated in the Zhongnan Hospital, Wuhan University, from 2018 to 2019, and investigated for their molecular characteristics, antibiotic resistance profiles, and clinical characteristics. The predominant lineage, SMRSA, accounted for 37.4% (34/91) of the isolates, followed by ST239-SCCmecIII-t030 (19.8%, 18/91) and ST59-SCCmecIV-t437 (8.8%, 8/91). In contrast to the latter two non-SMRSA (nSMRSA) lineages, which are among the main MRSA found in Chinese settings, SMRSA exhibited small colony variant (SCV) phenotype and had extremely high resistance rates to erythromycin (100.0%), clindamycin (100.0%), levofloxacin (100.0%), tetracycline (97.1%), moxifloxacin (97.1%), and ciprofloxacin (100%), but was more susceptible to rifampicin (resistance rate 3%). The levels of white blood cells (WBC) and procalcitonin (PCT) and the 30-day mortality in patients infected with SMRSA were (12.54 ± 6.61) × 109/L, 0.66 ng/mL, and 52.9%, respectively, which were much higher than those in patients infected with nSMRSA. In addition, patients infected with SMRSA were more frequently admitted to the intensive care unit (ICU) and submitted to invasive procedures than those infected with nSMRSA. In conclusion, SMRSA showed SCV phenotype and exhibited multiple antibiotic-resistance profiles. In this study, SMRSA was associated with serious infections and poor prognosis. Compared with ST239, ST59, or other nSMRSA strains, patients infected with SMRSA strains have higher 30-day mortality, increased levels of inflammatory biomarkers, and more frequent ICU hospitalization and invasive procedures.

scholarly journals Comparison of Methicillin-Resistant Staphylococcus aureus Isolates from Cellulitis and from Osteomyelitis in a Taiwan Hospital, 2016–2018

2019 ◽  
Vol 8 (6) ◽  
pp. 816 ◽  
Author(s):  
Kuo-Ti Peng ◽  
Tsung-Yu Huang ◽  
Yao-Chang Chiang ◽  
Yu-Yi Hsu ◽  
Fang-Yi Chuang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Joint Infection ◽  
Sccmec Type ◽  
Multidrug Resistant ◽  
Chang Gung Memorial Hospital ◽  
Methicillin Resistant ◽  
Mrsa Strains ◽  
Resistance Rates

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.

scholarly journals Antibiotic Resistance Pattern of Staphylococcus Aureus Isolated From Pediatrics With Ocular Infections: A 6-Year Hospital-Based Study in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiao-Yu Zheng ◽  
Bonnie Nga Kwan Choy ◽  
Ming-Ming Zhou ◽  
Zheng-Yan Zhao
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Rate ◽  
Resistance Pattern ◽  
Ocular Infection ◽  
Ocular Infections ◽  
Resistance Patterns ◽  
Mrsa Infection ◽  
Resistance Rates ◽  
Antibiotic Resistance Patterns

Staphylococcus aureus (S. aureus) is an important pathogen of ocular infections in pediatrics. The study aimed to identify the prevalence and resistance pattern of S. aureus, especially methicillin-resistant S. aureus (MRSA), in Chinese children with ocular infections. All patients with S. aureus infections were reviewed at a tertiary children's hospital during 2015–2020, and those with ocular infections were investigated for susceptibility results. Of 1,668 S. aureus strains, there were 177 unique isolates from ocular infection. Among them, 45 (25.4%) were MRSA and 132 (74.6%) were methicillin-sensitive S. aureus (MSSA). The proportion of MRSA did not change over time. Most of the strains were obtained from the neonate ward and ophthalmology department (n = 88, 49.7%, and n = 85, 48.0%, respectively), while eye secretion and pus were the main specimen types (n = 128, 72.3%, and n = 37, 20.9%, respectively). MRSA was significantly resistant against penicillin class (97.8%), erythromycin (71.1%), clindamycin (71.1%), and tetracycline (32.1%), with a high multidrug resistance (MDR) rate of 71.1%. However, MRSA was highly sensitive to levofloxacin. Resistance rates against erythromycin and ciprofloxacin as well as MDR percentage all increased among MSSA in children above 1 year of age, ophthalmology department, and outpatient population and decreased in eye secretion specimen. The mean resistance percentage remained stable for MRSA and MSSA during the study period. The survey of ocular S. aureus pathogens in pediatrics and their antibiotic resistance patterns helps in clinical treatment. MRSA with many strains demonstrating MDR is highly prevalent in children with ocular infections in Southeast China. Levofloxacin is an effective topical antibiotic for ocular MRSA infection, while erythromycin has a high resistance rate. The antibiotic resistance patterns of MRSA and MSSA differs and varies by different stratifications. A cautious use of antibiotics should be considered.

scholarly journals Nasal Carriage and Antibiotic Resistance Pattern of Methicillin-Resistant Staphylococcus aureus Isolates from Clinical Staff of a Referral Hospital, Zabol, Iran

2019 ◽  
Vol 4 (2) ◽  
pp. 81-85
Author(s):  
Mina Mir ◽  
Jalileh Kordi ◽  
Zahra Rashki Ghalehnoo ◽  
Omid Tadjrobehkar ◽  
Hamid Vaez
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Nasal Carriage ◽  
Resistance Rate ◽  
Referral Hospital ◽  
Resistance Pattern ◽  
Anatomical Site ◽  
Methicillin Resistant ◽  
Antibiotic Resistance Profile ◽  
Resistance Patterns

Introduction: Staphylococcus aureus is known as the causative agent of various infections in humans, and the nasal cavity is the main anatomical site for storing and spreading this pathogen in health care workers (HCWs) in hospital settings. Methicillin-resistant S. aureus (MRSA) strains are resistant to many antibiotics. The aim of this study was to investigate the prevalence and antibiotic resistance patterns of S. aureus strains isolated from the nasal carriage of HCWs in a referral hospital in Zabol. Methods: A total of 277 HCWs of Amir-Al-Momenin hospital of Zabol participated voluntarily in this study from March to September 2017. Demographic information was collected using questionnaire. Bacterial isolates were collected from anterior nasal canal using cotton swabs. MRSA isolates were detected by Oxacillin Screen agar and polymerase chain reaction (PCR). Antibiotic resistance was assessed by the disk-diffusion method.Results: In total, 10.8% of HCWs were carriers of S. aureus and 46.7% of the isolates were found to be MRSA. Laboratory staffs were the most frequently colonized HCWs. All the isolates were susceptible to vancomycin, teicoplanin and gentamicin. The highest resistance rate (64.3%) of MRSA isolates was observed against erythromycin.Conclusion: Our findings showed that gentamycin and rifampin might be useful to eradicate S.aureus. Regular screening of HCWs and assessment of antibiotic resistance profile are essential to prevent MRSA dissemination in hospitals.

scholarly journals Identification of Methicillin-Resistant Staphylococcus Aureus From Methicillin-Sensitive Staphylococcus Aureus and Molecular Characterization in Quanzhou, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhimin Bai ◽  
Min Chen ◽  
Qiaofa Lin ◽  
Ying Ye ◽  
Hongmei Fan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factor ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Protein A ◽  
Protein Sequences ◽  
Resistance Rate ◽  
Molecular Characteristics ◽  
Methicillin Resistant ◽  
Feature Vectors ◽  
N Gram

To distinguish Methicillin-Resistant Staphylococcus aureus (MRSA) from Methicillin-Sensitive Staphylococcus aureus (MSSA) in the protein sequences level, test the susceptibility to antibiotic of all Staphylococcus aureus isolates from Quanzhou hospitals, define the virulence factor and molecular characteristics of the MRSA isolates. MRSA and MSSA Pfam protein sequences were used to extract feature vectors of 188D, n-gram and 400D. Weka software was applied to classify the two Staphylococcus aureus and performance effect was evaluated. Antibiotic susceptibility testing of the 81 Staphylococcus aureus was performed by the Mérieux Microbial Analysis Instrument. The 65 MRSA isolates were characterized by Panton-Valentine leukocidin (PVL), X polymorphic region of Protein A (spa), multilocus sequence typing test (MLST), staphylococcus chromosomal cassette mec (SCCmec) typing. After comparing the results of Weka six classifiers, the highest correctly classified rates were 91.94, 70.16, and 62.90% from 188D, n-gram and 400D, respectively. Antimicrobial susceptibility test of the 81 Staphylococcus aureus: Penicillin-resistant rate was 100%. No resistance to teicoplanin, linezolid, and vancomycin. The resistance rate of the MRSA isolates to clindamycin, erythromycin and tetracycline was higher than that of the MSSAs. Among the 65 MRSA isolates, the positive rate of PVL gene was 47.7% (31/65). Seventeen sequence types (STs) were identified among the 65 isolates, and ST59 was the most prevalent. SCCmec type III and IV were observed at 24.6 and 72.3%, respectively. Two isolates did not be typed. Twenty-one spa types were identified, spa t437 (34/65, 52.3%) was the most predominant type. MRSA major clone type of molecular typing was CC59-ST59-spa t437-IV (28/65, 43.1%). Overall, 188D feature vectors can be applied to successfully distinguish MRSA from MSSA. In Quanzhou, the detection rate of PVL virulence factor was high, suggesting a high pathogenic risk of MRSA infection. The cross-infection of CA-MRSA and HA-MRSA was presented, the molecular characteristics were increasingly blurred, HA-MRSA with typical CA-MRSA molecular characteristics has become an important cause of healthcare-related infections. CC59-ST59-spa t437-IV was the main clone type in Quanzhou, which was rare in other parts of mainland China.

scholarly journals Infection Control of Spatial Disseminated Multi-Antibiotics Resistant And Phylo-Diverse Staphylococcus Aureus Pathotypes

2020 ◽  
Author(s):  
PAUL AKINDUTI ◽  
Joshua Osiyemi ◽  
Temitope Banjo ◽  
Oluwaseun Ejilude ◽  
Maged Ashker ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Infection Control ◽  
Urban Communities ◽  
Bovine Milk ◽  
Resistance Index ◽  
Resistance Rate ◽  
High Rate ◽  
Accessory Gene ◽  
Resistance Rates

Abstract Focal dissemination of multi-antibiotic resistant (MAR) Staphylococci pathotypes regulated by agr functionalities was investigated and evaluated for infection control. Non-repetitive Staphylococcus aureus strains from soft and skin infections disseminated in several communities were recovered and biotyped, assayed for biofilm and profiled for antibiotic resistance. Strains were further genotyped for spa types, virulence and resistant genes; and mapped for geospatial distribution. Clonal diversity and functional accessory gene regulators (agr) were also evaluated. Staphylococcal infection was not significant with age group (p>0.05), but high rate of MSSA (53.0%) and MRSA (1.5%) was observed. Median resistance rates were significantly differ (p=0.001) but highest 75 th percentile and media resistance rates were observed in wound infection. Resistance rate of 78.8% at MIC 50 32µg/ml and MIC 90 128µg/ml to amoxicillin-clavulanate, and more than 40% resistance to ceftazidime, ciprofloxacin, gentamycin, ofloxacin, sulfamethoxazole and tetracycline with MIC 90 and MIC 50 at 32 µg/ml were observed. More than 0.83 multi-antibiotic resistance index (MARI) were observed among the strains that clustered into separate phylo-group expressing high beta- lactamase and strong biofilm production. Heterogeneous spa types t442 (wound and pus), t657 (wound), t091 (ear) and t657 (ear and wound) revealed high phylo- diversity. Only 4.6% pvl + MSSA-CC1 agr I, pvl+ MSSA-CC5 (13.6%) and pvl+ MRSA-CC7 agr II (4.6%), expressed enterotoxin; sea, sec, sed, sej, Leukocidins ( LukF-PV, lukD, lukE ), proteases (aur, slpA sspB, sspE ) and resistance genes (fosB, msr (A), bla mph(C),aphA3, sat, fosB, sdrM, Q7A4X2) . Phylogenetic related spa types of livestock origin, specifically bovine milk clustered with detected strains that were prevalent in urban communities with focal dissemination to other nearest suburbs. Clonal dissemination resistant pvl+MAR MSSA-CC1 and MRSA- CC5 encoding agr were predominant in several peri-urban communities. This require adequate geno-surveillance, population-target antimicrobial stewardship, extensive community health care intervention policy and well-structured infection control programs to prevent further focal dissemination.

scholarly journals Predominance of PVL-negative community-associated methicillin-resistant Staphylococcus aureus sequence type 8 in newly diagnosed HIV-infected adults, Tanzania

2021 ◽  
Author(s):  
Joel Manyahi ◽  
Sabrina J. Moyo ◽  
Said Aboud ◽  
Nina Langeland ◽  
Bjørn Blomberg
Keyword(s):  
Staphylococcus Aureus ◽  
Hiv Infection ◽  
Diffusion Method ◽  
Molecular Characteristics ◽  
People Living With Hiv ◽  
Newly Diagnosed ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance

AbstractDifficult-to-treat infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are of concern in people living with HIV infection as they are more vulnerable to infection. We aimed to identify molecular characteristics of MRSA colonizing newly diagnosed HIV-infected adults in Tanzania. Individuals newly diagnosed with HIV infection were recruited in Dar es Salaam, Tanzania, from April 2017 to May 2018, as part of the randomized clinical trial CoTrimResist (ClinicalTrials.gov identifier: NCT03087890). Nasal/nasopharyngeal isolates of Staphylococcus aureus were susceptibility tested by disk diffusion method, and cefoxitin-resistant isolates were characterized by short-reads whole genome sequencing. Four percent (22/537) of patients carried MRSA in the nose/nasopharynx. MRSA isolates were frequently resistant towards gentamicin (95%), ciprofloxacin (91%), and erythromycin (82%) but less often towards trimethoprim-sulfamethoxazole (9%). Seventy-three percent had inducible clindamycin resistance. Erythromycin-resistant isolates harbored ermC (15/18) and LmrS (3/18) resistance genes. Ciprofloxacin resistance was mediated by mutations of the quinolone resistance-determining region (QRDR) sequence in the gyrA (S84L) and parC (S80Y) genes. All isolates belonged to the CC8 and ST8-SCCmecIV MRSA clone. Ninety-five percent of the MRSA isolates were spa-type t1476, and one exhibited spa-type t064. All isolates were negative for Panton-Valentine leucocidin (PVL) and arginine catabolic mobile element (ACME) type 1. All ST8-SCCmecIV-spa-t1476 MRSA clones from Tanzania were unrelated to the globally successful USA300 clone. Carriage of ST8 MRSA (non-USA300) was common among newly diagnosed HIV-infected adults in Tanzania. Frequent co-resistance to non-beta lactam antibiotics limits therapeutic options when infection occurs.

scholarly journals Mutation-Based Antibiotic Resistance Mechanism in Methicillin-Resistant Staphylococcus aureus Clinical Isolates

2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Active Site ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Resistance Mechanism ◽  
Ligand Docking ◽  
Clinical Samples ◽  
Allosteric Site ◽  
Methicillin Resistant

β-Lactam antibiotics target penicillin-binding proteins and inhibit the synthesis of peptidoglycan, a crucial step in cell wall biosynthesis. Staphylococcus aureus acquires resistance against β-lactam antibiotics by producing a penicillin-binding protein 2a (PBP2a), encoded by the mecA gene. PBP2a participates in peptidoglycan biosynthesis and exhibits a poor affinity towards β-lactam antibiotics. The current study was performed to determine the diversity and the role of missense mutations of PBP2a in the antibiotic resistance mechanism. The methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples were identified using phenotypic and genotypic techniques. The highest frequency (60%, 18 out of 30) of MRSA was observed in wound specimens. Sequence variation analysis of the mecA gene showed four amino acid substitutions (i.e., E239K, E239R, G246E, and E447K). The E239R mutation was found to be novel. The protein-ligand docking results showed that the E239R mutation in the allosteric site of PBP2a induces conformational changes in the active site and, thus, hinders its interaction with cefoxitin. Therefore, the present report indicates that mutation in the allosteric site of PBP2a provides a more closed active site conformation than wide-type PBP2a and then causes the high-level resistance to cefoxitin.

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