A Review of <i>Staphylococcus aureus</i>and the Emergence of Drug-Resistant Problem

There are various bacteria living in this world. The most common one is Staphylococcus aureus. Almost everyone has heard of it. It is easy to find their habitats, such as hospitals, homes, parks, schools etc. Some of them are difficult to be eliminated because of drug-resistant mutations. Hence, lots of researchers devoted their efforts to eliminate them. This review illustrates the characteristics of the Staphylococcus aureus and the main threat of their drug-resistant strains, especially methicillin-resistant S. aureus. What’s more, the article also highlights the plight in the drug development.

Antimicrobial drug resistance of Staphylococcus aureus in dairy products

Objective:To evaluate the prevalence of multidrug resistant Staphylococcus aureus(S.aureus) in dairy products.Methods:Isolation and identification of S.aureus were performed in 3 dairybased food products.The isolates were tested for their susceptibility to 5 different common antimicrobial drugs.Results:Of 50 samples examined,5(10%) were contaminated with 5. aureus.Subsequently,the 5 isolates were subjected to antimicrobial resistance pattern using five antibiotic discs(methicillin,vancomycin,kanamycin,chloramphenicol and tetracycline).Sample 29 showed resistance to methicillin and vancomycin.Sample 18 showed intermediate response to tetracycline.The other samples were susceptible to all the antibiotics tested.Conclusions:The results provide preliminary data on sources of food contamination which may act as vehicles for the transmission of antimicrobial-resistant Staphylococcus.Therefore,it enables us to develop preventive strategies to avoid the emergence of new strains of resistant S.aureus.

In-vitro antimicrobial activity of marine actinobacteria against multidrug resistance Staphylococcus aureus

Objective:To investigate the antibacterial aclivily of marine actinobacteria against multidrug resistance Staphylococcus aureus(MDRSA).Methods:Fifty one actinobacterial strains were isolated from salt pans soil,costal area in Kothapattanam,Ongole,Andhra Pradesh.Primary screening was done using cross-streak method against MDRSA.The bioaclive compounds are extracted from efficient actinobacteria using solvent extraction.The antimicrobial activity of crude and solvent extracts was perfomied using Kirby-Bauer method.MIC for ethyl acetate extract was determined by modified agar well diffusion method.The potent actinobacteria are identified using Nonomura key,Shirling and Gottlieb 1966 with Bergey's manual of determinative bacteriology.Results:Among the fifty one isolates screened for antibacterial activity,SRB25were found efficient against MDRSA.The ethyl acetate extracts showed high inhibition against test organism.MIC test was performed with the ethyl acetate extract against MDRSA and found to be 1 000μg/mL.The isolaled actinobacteria are identified as Streptomyces sp with the help of Nonomura key.Conclusions:The current investigation reveals that the marine actinobacteria from salt pan environment can be able to produce new drug molecules against drug resistant microorganisms.

Effect of Nano - Titanium Dioxide with Different Antibiotics against Methicillin-Resistant Staphylococcus Aureus

The different investigation has been carried out on the biological activities of titanium dioxide nanoparticle but the effect of this nano product on the antibacterial activity of different antibiotics has not been yet demonstrated. In this study the nano size TiO2 is synthesized using citric acid and alpha dextrose and the enhancement effect of TiO2 nanoparticle on the antibacterial activity of different antibiotics was evaluated against Methicillin-resistant Staphylococcus aureus (MRSA). During the present study, different concentrations of nano-scale TiO2 were tested to find out the best concentration that can have the most effective antibacterial property against the MRSA culture. Disk diffusion method was used to determine the antibacterial activity of these antibiotics in the absence and presence of sub inhibitory concentration of TiO2 nano particle. A clinical isolate of MRSA, isolated from Intensive Care Unit (ICU) was used as test strain. In the presence of sub-inhibitory concentration of TiO2 nanoparticle (20 μg/disc) the antibacterial activities of all antibiotics have been increased against test strain with minimum 2 mm to maximum 10mm. The highest increase in inhibitory zone for MRSA was observed against pencillin G and amikacin (each 10 mm). Conversely, in case of nalidixic acid, TiO2 nanoparticle showed a Synergic effect on the antibacterial activity of this antibiotic against test strain. These results signify that the TiO2 nanoparticle potentate the antimicrobial action of beta lactums, cephalosporins, aminoglycosides, glycopeptides, macrolids and lincosamides, tetracycline a possible utilization of nano compound in combination effect against MRSA.

Low-Level Antibiotic Resistance among Staphylococcus aureus and Gram-Negative Pathogens from Infected Skin and Soft Tissues in Rural Kenya

Introduction: Bacterial skin and soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient care visits whose causative agents are associated with a high antimicrobial resistance burden. For insights on antimicrobial susceptibilities in a rural setting, we examined specimens from suspected SSTIs from two public health facilities in Kenya. We additionally assessed antibiotic use, appropriateness of empiric therapy and risk factors for SSTI. Methodology: Between 2021 and 2023, 265 patients at Kisii and Nyamira County Referral hospitals were enrolled. Wound swabs/aspirates were collected and processed following standard microbiological procedures. Identification and antimicrobial susceptibility were performed using the VITEK 2 Compact platform. Demographic, clinical, and microbiological data were analyzed with R Statistical software. Results: S. aureus was isolated in 16.2% (43/265) of patients with a methicillin resistance (MRSA) proportion of 14% (6/43). While 13/15 drugs elicited susceptibilities ranging from 84% - 100%, penicillin (16%) and trimethoprim-sulfamethoxazole [TMP-SXT] (23%) yielded the lowest susceptibilities. Escherichia coli (n = 33), Klebsiella pneumoniae (n = 8), Pseudomonas aeruginosa (n = 8), and Citrobacter species (n = 4) were the most commonly isolated gram-negative species. Gram-negative strains showed high susceptibilities to most of the tested drugs (71% - 100%) with the exception of ampicillin (18%), TMP-SXT (33%), and first and second generation cephalosporins. Conclusions: The low MRSA prevalence and generally high antibiotic susceptibilities for S. aureus and gram-negative bacteria present opportunities for antibiotic stewardship in the study setting. Diminished susceptibilities against penicillin/ampicillin and TMP-SXT accord with prevailing local data and add a layer of evidence for their cautious empiric use.

Change in drug resistance of staphylococcus aureus

Objective To analyze the change in drug resistance of staphylococcus aureus(SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. Methods The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards(NCCLS) guidelines. Results SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillinresistant staphylococcus aureus(MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive staphylococcus aureus(MSSA)(P<0.05). In the dynamic observation of drug resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Conclusion Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

Betaine combined with traditional Chinese medicine ointment to treat skin wounds in microbially infected diabetic mice

BACKGROUND Skin wounds are highly common in diabetic patients,and with increasing types of pathogenic bacteria and antibiotic resistance,wounds and infections in diabetic patients are difficult to treat and heal.AIM To explore the effects of betaine ointment(BO)in promoting the healing of skin wounds and reducing the inflammation and apoptosis of skin cells in microbially infected diabetic mice.METHODS By detecting the minimum inhibitory concentrations(MICs)of betaine and plant monomer components such as psoralen,we prepared BO with betaine as the main ingredient,blended it with traditional Chinese medicines such as gromwell root and psoralen,and evaluated its antibacterial effects and safety in vitro and in vivo.The skin infection wound models of ordinary mice and diabetic mice were constructed,and the OTC drugs mupirocin ointment and Zicao ointment were used as controls to evaluate the antibacterial effects in vivo and the anti-inflammatory and anti-apoptotic effects of BO.RESULTS The MICs of betaine against microorganisms such as Staphylococcus aureus(S.aureus),Candida albicans and Cryptococcus neoformans ranged from 4 to 32μg/mL.Gromwell root and psoralea,both of which contain antimicrobial components,mixed to prepare BO with MICs ranging from 16 to 64μg/mL,which is 32-256 times lower than those of Zicao ointment,although the MIC is greater than that of betaine.After 15 days of treatment with BO for USA300-infected ordinary mice,the wound scab removal rates were 83.3%,while those of mupirocin ointment and Zicao ointment were 66.7%and 0%,respectively,and the differences were statistically significant.In diabetic mice,the wound scab removal rate of BO and mupirolacin ointment was 80.0%,but BO reduced wound inflammation and the apoptosis of skin cells and facilitated wound healing.CONCLUSION The ointment prepared by mixing betaine and traditional Chinese medicine can effectively inhibit common skin microorganisms and has a strong effect on the skin wounds of sensitive or drug-resistant S.aureus-infected ordinary mice and diabetic mice.

Phage therapy: An alternative to antibiotics in the age of multi-drug resistance

The practice of phage therapy, which uses bacterial viruses(phages) to treat bacterial infections, has been around for almost a century. The universal decline in the effectiveness of antibiotics has generated renewed interest in revisiting this practice. Conventionally, phage therapy relies on the use of naturally-occurring phages to infect and lyse bacteria at the site of infection. Biotechnological advances have further expanded the repertoire of potential phage therapeutics to include novel strategies using bioengineered phages and purified phage lytic proteins. Current research on the use of phages and their lytic proteins against multidrug-resistant bacterial infections, suggests phage therapy has the potential to be used as either an alternative or a supplement to antibiotic treatments. Antibacterial therapies, whether phage-or antibiotic-based, each have relative advantages and disadvantages; accordingly, many considerations must be taken into account when designing novel therapeutic approaches for preventing and treating bacterial infection. Although much about phages and human health is still being discovered, the time to take phage therapy serious again seems to be rapidly approaching.

Effects of Taxotere on invasive potential and multidrug resistance phenotype in pancreatic carcinoma cell line SUIT-2

INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relationship between expression of multidrugresistance (MDR) phenotype P-glycoprotein (P-gp)and the malignant properties of tumors, but theresults are often conflicting[1-8]. The difference intumor types or MDR phenotype induced by specificagents might account for this discrepancy. Taxotere(TXT), a member of the family of taxanes, hasantitumor activity through its effect of promotingthe polymerization of tubulin[9,10].

呼吸道与非呼吸道标本分离MRSA临床株耐药性比较及其分子流行病学特征

目的:探讨呼吸道与非呼吸道标本分离耐甲氧西林金黄色葡萄球菌(MRSA)的耐药性、分子分型和生物膜形成能力的差异。方法:选取住院患者送检标本中分离出的100株MRSA,其中50株MRSA分离自呼吸道标本,50株MRSA分离自非呼吸道标本。对100株MRSA进行14种抗菌药物的体外药敏试验,采用多位点序列分型(MLST)和金黄色葡萄球菌A蛋白(Spa)分型方法进行分子分型,结晶紫染色实验检测MRSA菌株生物膜形成能力。结果:体外药敏试验,100株MRSA对青霉素、红霉素、克林霉素、左氧氟沙星、环丙沙星、莫西沙星和四环素的总体耐药率较高,均大于60.0%,对复方新诺明耐药率仅为9.0%,且所有菌株均对万古霉素、利奈唑胺、替加环素和奎奴普丁/达福普汀敏感。呼吸道标本分离的MRSA对莫西沙星、左氧氟沙星、环丙沙星、四环素和庆大霉素的耐药率明显高于非呼吸道标本分离株(P<0.05)。100株MRSA中共检出17种基因型,其中优势型别为ST5-t2460型(26.0%)、ST239-t030型(23.0%)和ST59-t437型(20.0%)。呼吸道标本分离MRSA中优势型别为ST5-t2460型(20.0%)和ST239-t030型(13.0%),其次为ST59-t437型(7.0%);非呼吸道标本分离MRSA中共检出13种基因型,优势型别为ST59-t437型(13.0%)和ST239-t030型(10.0%)。100株MRSA全部为产膜菌株,强产膜菌株、中产膜菌株和弱产膜菌株比例分别为2.0%(2/100)、24.0%(24/100)和74.0%(74/100)。ST59-t437型克隆株整体产膜能力较强,60.0%(12/20)为中产膜株和强产膜株。结论:呼吸道标本分离MRSA菌株整体耐药率明显高于非呼吸道标本分离MRSA株。ST59-t437基因型和ST239-t030基因型为2类标本共有优势克隆株,ST59-t437型菌株呈现较强的生物膜形成能力,而ST239-t030型菌株整体耐药性最强。

基于全基因组重测序技术的浙江近岸海域耐盐金黄色葡萄球菌(Staphylococcus aureus)耐药机制解析

金黄色葡萄球菌(Staphylococcus aureus)是近岸海域海水中的主要病原菌,严重威胁接触者的安全。抗生素处理是治疗金黄色葡萄球菌感染的重要手段,其耐药性的发生受到了高度重视。采用全基因组重测序与KEGG富集分析结合的方法,对红霉素(erythromycin)、氯霉素(chloramphenicol)和万古霉素(vancomycin)处理后的耐盐金黄色葡萄球菌(S.aureus ZS01)和不耐盐金黄色葡萄球菌(S.aureus 502A)进行耐药机制研究。结果表明,S.aureus 502A经抗生素处理后发生突变的程度大于S.aureus ZS01,二者在经过氯霉素处理发生了更大程度的突变。红霉素、氯霉素和万古霉素处理主要影响了金黄色葡萄球菌的致病能力;红霉素和氯霉素可能通过影响金黄色葡萄球菌脂类的代谢引起其耐药性的变化。除此之外,三种抗生素处理均出现了较多TIGR01741家族蛋白和假设蛋白基因的突变,推测与菌株的耐药性和致病性相关。耐盐金黄色葡萄球菌可通过外排系统作用产生红霉素耐药性,不耐盐菌株因细胞壁成分相关基因的突变提高了对万古霉素的耐受性。研究结果可为耐盐和不耐盐金黄色葡萄球菌的耐药机制及抗生素对金黄色葡萄球菌致病性影响的研究提供基础数据。

Polymorphisms of the oxidant enzymes glutathione S-transferase and glutathione reductase and their association with resistance of Plasmodium falciparum isolates to antimalarial drugs

Objective:To investigate the association between amplification of the two regulatory genes controlling glutathione(GSH) levels,glutathione reductase(PfGR) and glutathione S-transferase (PfGST) genes and sensitivity of Plasmodium falciparum(P.falciparum) isolates collected from different malaria endemic areas of Thailand to standard antimalarial drugs.Methods:A total of 70 P.falciparum isolates were collected from endemic areas of multi-drug resistance (Tak,Chantaburi and Ranong Provinces) during the year 2008-2009.The in vitro assessment of antimalarial activity of P.falciparum clones(K1- and Dd2 chloroquine resistant and 3D7- chloroquine sensitive) and isolates to chloroquine,quinine,mefloquine and arteusnate was performed based on SYBR Green modified assay.Results:68(97.14%),11(15.71%) and 28(40%) isolates respectively were classified as chloroquine-,quinine- and mefloquine-resistant isolates. With this limited number of P.falciparum isolates included in the analysis,no significant association between amplification of PfGST gene and sensitivity of the parasite to chloroquine, quinine,mefloquine and quinine was found.Based on PCR analysis,Dd2,Kl and 3D7 clones all contained only one copy of the PfGST gene.All isolates(70) also carried only one copy number of PfGST gene.There appears to be an association between amplification of PfGR gene and chloroquine resistance.The 3D7 and Dd2 clones were found to carry only one PfGR gene copy, whereas the K1 clone carried two gene copies.Conclusions:Chloroquine resistance is likely to be a consequence of multi-factors and enzymes in the GSH system may be partly involved. Larger number of parasite isolates are required to increase power of the hypothesis testing in order to confirm the involvement of both genes as well as other genes implicated in glutathione metabolism in conferring chloroquine resistance.

Resistance to Anti-Thyroid Drugs in Graves’ Disease: Clinical-Biological Characteristics and Alternative Therapy in Tropical Area

Background: Resistance to anti-thyroid drugs (ATDs) is a rare entity recently described. We report two African observations in the treatment of Graves’ disease. Case 1: A 19-year-old Senegalese woman presented on admission with thyrotoxicosis syndrome associated with diffuse goitre and Grave’s orbitopathy. TSH levels were low (0.005 mIU/ml;N = 0.27 - 4.20) and fT4 elevated (60 pmol/L;N = 12 - 22]. Combination therapy with propranolol (40 mg/day) and carbimazole (starting dose of 45 mg/day and increased to 60 mg/day) was initiated. In view of the persistence of symptoms despite good therapeutic compliance, carbimazole was replaced by methimazole with an initial starting dose of 40 mg/day, followed by 60 mg/day. Despite the change in therapy, clinical symptoms of thyrotoxicosis persisted, and fT4 levels remained elevated. The patient was diagnosed with resistance to ATDs in Graves’ disease. Total thyroidectomy following 10 days of preoperative preparation with 1% Lugol’s solution was performed successfully. Case 2: A 22-year-old woman was referred for continued management of Graves’ disease with elevated thyroid-stimulating hormone receptor antibody (TRAb) levels (34 UI/mL;N < 1.75). Treatment included propranolol (80 mg/day) and carbimazole at an unusual dose of 80 mg/day. Combined therapy was clinically and biologically ineffective, with an fT4 level of 100 pmol/L [N: 12 - 22]. Upon admission, methimazole (40 mg/day) followed by propylthiouracil (800 mg/day) replaced carbimazole. Despite good patient compliance, the patient’s symptoms remained unaltered and fT4 levels elevated. A total robot thyroidectomy using the right axillary approach was performed successfully after 10 days of preoperative preparation, including prednisone (40 mg/day) combined with 1% Lugol’s solution. Conclusion: Resistance to ATDs complicates the management of Graves’ disease. Total thyroidectomy following preoperative preparation with Lugol’s solution and/or corticosteroids was shown to be successful.

Anticancer Drug Resistance of HeLa Cells Transfected With Rat Glutathione S-transferase pi Gene

To establish a cytologic expressing system of rat glutathione S-transferase pi (GST-pi) cDNA for detecting the resistance of HeLa cells to anticancer drugs. Methods The assessment was made with various anticancer drugs (adriamycin, mitomycin, cisplatinum and vincristine) that showed different cytotoxicities in transfectant HeLa cells with pSV-GT containing rat GST-pi cDNA (HeLa/pSV-GT) or control pSV-neo (HeLa/pSV-neo). Expression levels of GST-pi mRNA in HeLa/pSV-GT and HeLa/pSV-neo were measured by in situ hybridization using Digoxin-labelled cDNA probe. Results HeLa/pSV-GT expressed significantly high degree of GST-pi mRNA, whereas both HeLa/pSV-neo and HeLa cells had very low expression. Cytotoxicities of HeLa/pSV-GT and HeLa/pSV-neo with 4 anticancer drugs were measured by MTT assay. Drug concentrations for yielding 50% inhibition (IC50) in HeLa/pSV-GT by adriamycin, mitomycin and cisplatinum were 70.13 靏/mL, 10.95 靏/mL and 16.52 靏/mL, respectively. In contrast, IC50 in HeLa/pSV-neo was 10.34 靏/mL, 7.48 靏/mL and 13.70 靏/mL, respectively. The cytotoxicities of vincristine on both HeLa/pSV-GT and HeLa/pSV-neo were not significantly different. Conclusions Our findings suggest that HeLa/pSV-GT containing rat GST-pi cDNA is resistant to some anticancer drugs due to overexpression of GST-pi. Also, HeLa/pSV-GT cell line could serve as a useful cytogenetic model for further research.

Unlocking epigenetics for precision treatment of Ewing’s sarcoma

Ewing’s sarcoma(EWS)is a highly aggressive malignant bone tumor primarily affecting adolescents and young adults.Despite the efficacy of chemoradiotherapy in some cases,the cure rate for patients with metastatic and recurrent disease remains low.Therefore,there is an urgent need for innovative therapeutic approaches to address the challenges associated with EWS treatment.Epigenetic regulation,a crucial factor in physiological processes,plays a significant role in controlling cell proliferation,maintaining gene integrity,and regulating transcription.Recent studies highlight the importance of abnormal epigenetic regulation in the initiation and progression of EWS.A comprehensive understanding of the intricate interactions between EWS and aberrant epigenetic regulation is essential for advancing clinical drug development.This review aims to provide a comprehensive overview of both epigenetic targets implicated in EWS,integrating various therapeutic modalities to offer innovative perspectives for the clinical diagnosis and treatment of EWS.

Study on Antibacterial Effect of Single Chinese Herbs on Staphylococcus aureus

[Objectives] This study was conducted to determine in-vitro antibacterial effect of 58 Chinese herbs on Staphylococcus aureus,and screen single Chinese herbs with better in-vitro antibacterial effect for formulation of prescription. [Methods]Effective components in Chinese herbs were extracted with water,and inhibition zone diameters and minimal inhibitory concentrations of the 58 Chinese herbs against S. aureus were determined by agar plate punching method and micro two-fold method,respectively. [Results] Twenty two kinds of Chinese herbs including Terminalia chebula Retz.,Anemarrhena asphodeloides Bunge.,Prunella vulgaris L,Rheum palmatum L. and Mosla chinensis Maxim. had better antibacterial effect,among which T. chebula Retz.,A. asphodeloides Bunge.,P. vulgaris L,R. palmatum L. and C. sappan Linn showed the best antibacterial effect,with average inhibition zone over 20 mm and MIC lower than 15. 6 mg/ml.[Conclusions]Traditional Chinese herbs have certain antibacterial effect,and this study will provide important theoretical reference for clinical medication and development of prescription.

Molecular Diversity of <i>Staphylococcus aureus</i>from the Nares of Hospital Personnel, HIV-Positive and Diabetes Mellitus Patients in Yaounde Cameroon

Nasal carriage of Staphylococcus aureus has been identified as a risk factor for the development of staphylococcal infections caused by endogenous colonizing strains. Information on the genotypic diversity of Staphylococcus aureus is relevant for managing epidemiological and clinical challenges resulting from the evolutionary differences of this bacterium. The objective of this study was to determine and compare the molecular diversity of Staphylococcus aureus isolates from three high-risk populations in Yaounde, Cameroon. Molecular analysis confirmed that 95% of 100 tested isolates were S. aureus. The mecA and Panton Valentine-Leukocidin (PVL) genes (lukS/F-PV) were detected in 37% (35/95) and 43% (41/95) of isolates respectively and 18% (17/95) of the isolates harboured both the mecA and lukS/F-PV genes. A mixed distribution of both methicillin sensitive S. aureus (MSSA)/PVL and methicillin resistant S. aureus (MRSA)/PVL strains were detected within the study population. Community associated MRSA accounted for 94% (33/35) of the isolates, further classified into allotypes SCCmec type IV 54% (19/35) and SCCmec type V 40% (14/35), while two isolates were hospital associated SCCmec type II strains. A majority of the isolates harboured a single aggressive gene regulator allele agr type I. Pulsed Field Gel Electrophoresis (PFGE) generated 18 pulsotypes that grouped isolates irrespective of the study population. Multilocus Sequence Typing (MLST) of 12 selected isolates was assigned to six pandemic clonal complexes (CC): CC5 (ST5), CC8 [ST8, (n = 3)], CC15 (ST 15), CC25 (ST 25), CC72 [ST72 (n = 2)] and CC121 [ST 121 (n = 2)] and three atypical sequence types ST 508, ST 699 (CC45) and ST 1289 (CC 88). The study population represents an important reservoir for MRSA, MRSA-PVL and MSSA-PVL which could serve as focal point for further dissemination bringing about significant clinical and epidemiological implications. The predominance of SCCmec IV and agr types in this setting warrants further investigation. Isolates were genetically diverse with MLST indicating that pandemic ST8 was predominant. Detection of atypical STs has provided an insight into the necessity for constant monitoring.

某三甲肿瘤专科医院MRSA流行情况及耐药性分析

目的了解耐甲氧西林金黄色葡萄球菌(MRSA)在肿瘤医院的感染流行情况及耐药情况,为较好地预防和控制MRSA在医院内的感染流行,为临床用药提供参考。方法对重庆大学附属肿瘤医院2019年1月-2023年12月从临床样本中分离金黄色葡萄球菌(SAU)和MRSA菌株进行数量及耐药性的统计分析,并统计MRSA主动筛查分离的SAU和MRSA菌株数量,并进行年度间的比较。结果这5年SAU和MRSA检出率呈波动状态,对各类抗菌药物的耐药性变化不大。达托霉素、替加环素、利奈唑胺和万古霉素敏感,对其他药物有不同程度耐药性,所有的SAU对青霉素、红霉素、克林霉素耐药率较高,对氟喹诺酮类、氨基糖苷类耐药率较低。5年MRSA菌株对β内酰胺类、克林霉素、红霉素耐药率高于非MRSA菌株。MRSA主动筛查中MRSA主要分布在侵入性治疗较多的科室。结论临床MRSA检出率较高,对大多数抗菌药物耐药,应对重点科室持续进行MRSA的主动筛查,及时进行消毒隔离,临床合理使用抗菌药物,有助于控制MRSA传播。

利奈唑胺、替加环素、达托霉素、头孢吡普等抗菌药物对MRSA的抗菌活性

目的多中心研究我国2005年MRSA的耐药现状，评价利奈唑胺、替加环素、达托霉素和头孢吡普等药物的抗菌活性。方法收集2005年1月至2005年12月14个地区连续分离的非重复金葡菌809株，采用琼脂稀释法测定抗菌药物的MIC。结果MRSA发生率为50．3％，其中MRSA发生率最高的为大连（93．3％）、上海（80．3％），其次为南宁（63．6％）、北京（55．5％）、青岛（53．8％）。MRSA对红霉素的敏感性为4．2％，喹诺酮类药物为4．4％～12．6％，庆大霉素为9．6％，四环素为11．1％，对MRSA活性较高的有氯霉素（82．3％）和复方磺胺甲嗯唑（78．6％）；MRSA对替考拉宁、万古霉素、利奈唑胺、替加环素、达托霉素和头孢吡普均全部敏感。头孢吡普、达托霉素、替加环素、利奈唑胺的MIC50和MIC90分别为2，2mg／L；0．5，0．5mg／L；0．125，0．25mg／L；1，2mg／L。MIC范围分别为0．125～2mg／L，0．125～1mg／L,0.064～0．5mg／L，0．25～2mg／L。结论我国MRSA发生率高，多重耐药严重，不同地区MRSA发生率有所差异，头孢吡普、达托霉素、替加环素和利奈唑胺对于MRSA具有很高的抗菌活性。

金黄色葡萄球菌及其甲氧苯青霉素耐药性的MALDI-TOF MS鉴定

用MALDI_TOFMS细菌指纹图谱鉴定细菌 ,建立区分金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株的MALDI_TOFMS分析方法,检测了76株从临床标本中分离得到的金黄色葡萄球菌 ,用软件进行聚类分析,以nuc(耐热核酸酶)基因和mecA(耐药)基因聚合酶链反应(PCR)检测结果为参照 ,74 %的菌株经MALDI_TOFMS给出了正确的鉴定结果;金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株的质谱图有很大差别 ,各自有其特征峰;经过软件聚类分析 ,76株实验菌株划分为敏感群和耐药群;与PCR检测结果对照 ,有7株菌PCR检测mecA基因为阴性 ,而经MALDI_TOFMS鉴定为耐药株 ,表型鉴定表明其中有5株为敏感株;利用细菌指纹图谱和数据库检索对大多数菌株实现了正确鉴定;MALDI_TOFMS分辨率高 ,甚至可以区分株间的差异 ,实现了区分金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株;