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Abstract Infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) are still associated with significant morbidity and mortality. Treatment failures of cefazolin (CFZ) have been reported and probably related to the inoculum effect. New treatments for severe MSSA infections are needed and ceftaroline fosamil (CPT) could be an option. Our aim was to describe the clinical characteristics of five patients with com plicated MSSA bacteremia failing CFZ and successfully treated with CPT. We performed a retrospective chart review in a Hospital in Buenos Aires, Argentina; in a 12-month period, five patients (24%) of 21 with MSSA bacteremia experienced CFZ failure and were salvaged with CPT. The median time of CFZ therapy was 10 days before changing to CPT; four patients had evidence of metastatic spread and 2 had endocarditis. All patients experienced microbiological and clinical cure with CPT, which was used as monotherapy in 4 and in combination with daptomycin in another. One patient discontinued CPT due to neutropenia on day 23 of treatment. In patients with MSSA BSI failing current therapy, CPT could be a good therapeutic option.
Resumen Las infecciones causadas por Staphylococcus aureus sensible a la meticilina (SASM) todavía se asocian con una morbilidad y mortalidad significativas. Se han informado fallas en el tratamiento de cefazolina (CFZ) probablemente relacionadas con efecto inóculo. Nuevos tratamientos son necesarios para estas infecciones y ceftarolina fosamil (CPT) podría ser una opción. Nuestro objetivo fue describir las características clínicas de cinco pacientes con bacteriemia por SASM complicada con falla a CFZ y que fueron exitosamente tratados con CPT. Realizamos una revisión retrospectiva de historias clínicas en un hospital de Buenos Aires, Argentina; en un período de 12 meses, cinco pacientes (24%) de 21 con bacteriemia por SASM experimentaron falla a CFZ y fueron tratados con CPT. La mediana de tiempo de la terapia con CFZ fue de 10 días antes de cambiar a CPT; cuatro pacientes presentaban evidencia de diseminación metastásica y 2 tenían endocarditis. Todos los pacientes experimen taron curación microbiológica y clínica con CPT, que se utilizó como monoterapia en 4 y en combinación con daptomicina en otro. Un paciente interrumpió CPT debido a neutropenia el día 23 de tratamiento. En enfermos con infecciones graves por SASM que fallan en la terapia actual, CPT podría ser una buena opción terapéutica.
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Aims@#Diabetic foot infections (DFIs) represent one of the most important risk factors for lower extremity amputation. One of the major infection agents that causes DFIs is Staphylococcus aureus. Staphylococcus aureus is an important human pathogen causing variety of clinical manifestations which can lead to invasive infections, sepsis and even death. Outcomes of antibiotic treatment of diabetic foot infections may depend not only on the antimicrobial susceptibility of the etiological agents, but also their ability to produce diverse virulence factors. This study was aimed to investigate biofilm production and the presence of various virulence genes among Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible Staphylococcus aureus (MSSA) isolates obtained from patients with DFIs. @*Methodology and results@#A total of 48 clinical MRSA and MSSA isolates obtained from diabetic foot patients were studied for their biofilm formation and the presence of 29 known virulence genes. The biofilm formation was observed, analyzed and quantified using the microtiter plate method. Biofilm production was observed as 95.50% and 92.00% in the MRSA and MSSA isolates, respectively. Among the 29 virulence genes tested on the 48 clinical isolates, 19 virulence genes were detected. It was found that aap (62.50%), etd (54.17%), icaD (50.00%), aae (50.00%), seh (31.25%) and icaADB (22.92%) were the most prevalent genes. A total of 10 virulence genes (etb, gehD, icaB, icaC, seb, hla_haem, hld_epid, altE, fbe and sesI) were absent in all the isolates used.@*Conclusion, significance and impact of study@#Virulence genes play important role in clinical infections. Our results showed the presence rates of biofilm formation and accumulation-associated factors that are high among MRSA as well as MSSA isolates from DFIs. These results confirmed the importance of biofilm formation as regarded for DFIs.
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Methicillin Resistance , Methicillin-Resistant Staphylococcus aureus , Diabetic FootABSTRACT
Objective To investigate the clinical characteristics and prognosis analysis of patient with bacteremia induced by Methicillin-susceptible Staphylococcus aureus (MSSA) or Methicillin-resistant Staphylococcus aureus (MRSA).Methods This retrospective study included 95 Staphylococcus aureus Bacteremia (SAB) patients admitted to Nanjing Drum Tower hospital from January 2012 to December 2017.According to the drug sensitivity tests,patients were divided into MSSA group and MRSA group.Clinical characteristics,systematic score and prognosis were compared between these two group.APACHE Ⅱ score and SOFA score were analyzed by independent-samples t test.The distribution of primary disease and basic disease,bacterium source,and prognostic factors were analyzed by Mann—Whitney U test or x2 test.The cumulative survival was calculated by the Kaplan-Meier method.Wilcoxon rank sum test was selected for survival rate comparison.Results There are 56 MSSA strain and 39 MRSA strain among the 95 SAB patients,the detection rate is 58.95％ and 41.05％,respectively.The most common primary disease of SAB is catheter-related infections(23 cases,24.21％).Compared with MSSA group,the catheter-related infections has higher detection rate of MRSA obviously (P＜0.01).The most common underlying disease of SAB is diabetes (35 cases,36.84％).Compared with MSSA,MRSA is more frequent appear in SAB patients combine with renal dysfunction (28 cases,29.47％).The third disease is cardiac insufficiency (22 cases,23.16％).The community-acquired SAB is fifty-two and the majority of strains is MSSA.The hospital-acquired SAB is forty-three and mainly of them is MRSA.The Sepsis related Organ Failure Assessment (SOFA) score of MRSA group are higher than MSSA significantly (t=2.203,P=0.024).However,there is no significant differences between MSSA and MRSA group in APACHE Ⅱ score,cases of hospitalized beyond 30 days and 28-days survival rate (P ＞ 0.05).Conclusions The majority of strains in the SAB patients is MSSA.In clinical characteristics,compared with MSSA,MRSA is more common in nosocomial infection,catheter related infection and renal dysfunction patients.There is no significant differences in prognosis between MSSA group and MRSA group.
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Objective: To determine the prevalence, genetic relatedness, and pattern of antimicrobial susceptibility in methicillin-resistant Staphylococcus aureus ( S. aureus) (MRSA) isolated from household dogs, farm dogs, and stray dogs, compared to isolates from their associated personnel. Methods: MRSA was isolated from 250 nasal swabs (150 swabs from dogs and 100 swabs from humans). PCR assays were used to detect the presence of both the nuc and mecA genes, which confirmed the identity of S. aureus isolates and the presence of methicillin resistance, respectively. Disk diffusion was used to determine the antibiotic susceptibility against 15 antimicrobial agents along with an E-test that determined the minimum inhibitory concentration for oxacillin. Pulsed field gel electrophoresis was conducted to determine the genetic relatedness of MRSA isolates from dogs to those from associated and unassociated personnel. Results: The prevalence of S. aureus in dogs and humans was 12.7% and 10.0% respectively, while the prevalence of MRSA isolates in dogs and humans was 5.3% and 5.0%, respectively. The prevalence of MRSA isolates in household dogs, farm dogs, and stray dogs was 7.8%, 4.7%, and 0.0%, respectively. MRSA isolates demonstrated a significantly higher rate of multi-resistance against three or more antimicrobial agents than methicillin-susceptible S. aureus (MSSA). Trimethoprim-sulphamethoxazole and chloramphenicol were the most effective antibiotics against all MRSA isolates. Pulsed field gel electrophoresis revealed a strong association between dog MRSA isolates and MRSA isolates from strongly associated personnel. Conclusions: MRSA is prevalent in house dogs, as well as in dog rearing centers and among their strongly associated personnel. A strong association was found between the MRSA isolates from dogs and those from humans who are in close contact. In addition, MRSA isolates showed a high rate of multi-resistance compared to MSSA isolates.
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Objective:To determine the prevalence, genetic relatedness, and pattern of antimicrobial susceptibility in methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA) isolated from household dogs, farm dogs, and stray dogs, compared to isolates from their associated personnel. Methods: MRSA was isolated from 250 nasal swabs (150 swabs from dogs and 100 swabs from humans). PCR assays were used to detect the presence of both the nuc and mecA genes, which confirmed the identity of S. aureus isolates and the presence of methicillin resistance, respectively. Disk diffusion was used to determine the antibiotic susceptibility against 15 antimicrobial agents along with an E-test that determined the minimum inhibitory concentration for oxacillin. Pulsed field gel electrophoresis was conducted to determine the genetic relatedness of MRSA isolates from dogs to those from associated and unassociated personnel. Results:The prevalence of S. aureus in dogs and humans was 12.7%and 10.0%respectively, while the prevalence of MRSA isolates in dogs and humans was 5.3%and 5.0%, respectively. The prevalence of MRSA isolates in household dogs, farm dogs, and stray dogs was 7.8%, 4.7%, and 0.0%, respectively. MRSA isolates demonstrated a significantly higher rate of multi-resistance against three or more antimicrobial agents than methicillin-susceptible S. aureus (MSSA). Trimethoprim-sulphamethoxazole and chloramphenicol were the most effective antibiotics against all MRSA isolates. Pulsed field gel electrophoresis revealed a strong association between dog MRSA isolates and MRSA isolates from strongly associated personnel. Conclusions:MRSA is prevalent in house dogs, as well as in dog rearing centers and among their strongly associated personnel. A strong association was found between the MRSA isolates from dogs and those from humans who are in close contact. In addition, MRSA isolates showed a high rate of multi-resistance compared to MSSA isolates.
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Introduction Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have become common in hospitals and the community environment, and this wide resistance has limited patient treatment. Clindamycin (CL) represents an important alternative therapy for infections caused by S. aureus. Antimicrobial susceptibility testing using standard methods may not detect inducible CL resistance. This study was performed to detect the phenotypes of resistance to macrolides-lincosamides-streptogramin B (MLSB) antibiotics, including CL, in clinical samples of S. aureus from patients at a tertiary hospital in Santa Maria, State of Rio Grande do Sul, Brazil. Methods One hundred and forty clinical isolates were submitted to the disk diffusion induction test (D-test) with an erythromycin (ER) disk positioned at a distance of 20mm from a CL disk. The results were interpreted according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI). Results In this study, 29 (20.7%) of the 140 S. aureus samples were resistant to methicillin (MRSA), and 111 (79.3%) were susceptible to methicillin (MSSA). The constitutive resistance phenotype (cMLSB) was observed in 20 (14.3%) MRSA samples and in 5 (3.6%) MSSA samples, whereas the inducible resistance phenotype (iMLSB) was observed in 3 (2.1%) MRSA samples and in 8 (5.8%) MSSA samples. Conclusions The D-test is essential for detecting the iMLSB phenotype because the early identification of this phenotype allows clinicians to choose an appropriate treatment for patients. Furthermore, this test is simple, easy to perform and inexpensive. .
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Humans , Anti-Bacterial Agents/pharmacology , Clindamycin/pharmacology , Erythromycin/pharmacology , Staphylococcus aureus/drug effects , Drug Resistance, Multiple, Bacterial , Microbial Sensitivity Tests , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Phenotype , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purification , Tertiary Care CentersABSTRACT
Objective To analyze the distribution and drug resistance rate of methicillin-resisitant Staphylococcus aureus(MRSA) and methicillin-susceptible Staphylococcus aureus(MSSA) isolated from different departments in a certain primary hospital during 2009 to 2012,and to provide scientific evidences for clinical application of antibiotics.Methods Pathogens and bacterial resistance to antibiotics were identified using the VITEK 2 compact equipment.The data were got from WHONTES.5 and analyzed by SPSS 13.0.Results There were 517 Staphylococcus aureus strains were detected(MRSA 135 strains,MSSA 382 strains).The rate of MRSA was 24.5％,27.7％,24.8％,27.0％ during the four years.MRSA was mainly found in the department of oncology,orthopaedicsand ICU.MRSA was mainly isolated from pus,secretion,sputum and blood.The 517 Staphylococcus aureus strains showed high sensitive to vancomycin,linezolid and teicoplanin,the sensitive rate was 100％.Conclusion Establishing a more comprehensive MDRO monitoring and hospital infection control system in the primary hospital,and rational using antibacterial drugs at the based of the antibiotics susceptibility test in the treatment can be effective in preventing MRSA resistance rates increasing and hospital-borne.
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BACKGROUND: Guava is a native plant in the Philippines and is available throughout the year. Several studies show that it exhibits anti-microbial activity on different bacteria. However, little is known on its anti-MRSA activity. The leaves of this plant if proven to have antibacterial properties against MRSA would be a very cost-effective drug against MRSA infected wounds.METHODS: This study determined the in vitro antimicrobial activity of a 50 percent solution of the lyophilized guava leaf crude aqueous extract on Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA) in comparison with 30 mg vancomycin and 10 mg fusidic acid. The inhibitory effects of the three treatments were tested on two reference strains (MRSA ATCC 43300 and MSSA ATCC 25923), and four clinical MRSA isolates (1 MRSA from blood, and 3 MRSA from wound), using Disc Diffusion Assay. Microdilution Broth Assay was done to determine the Minimum Inhibitory Concentration (MIC) of guava extract and vancomycin.RESULTS: The highest inhibition was observed in fusidic acid (36 mm) followed by guava (21 mm) and then by vancomycin (18 mm). Vancomycin and guava have the same inhibitory effects against MSSA reference strain and MRSA wound 2 isolate. The effects of the three treatments on MRSA reference strain are comparable with all the clinical MRSA isolates. Guava is more effective to MRSA reference strain (24.6 mm) than MSSA reference strain (17.6 mm). However, vancomycin and fusidic acid have the same effects on both MRSA and MSSA reference strains. The effects of guava and fusidic acid on all clinical MRSA isolates (20.25 mm and 36.85 mm, respectively) are greater than their effects on MSSA ATCC 25923 (17.6 mm and 32.2 mm, respectively). Furthermore, Microdilution Broth Assay results showed that using 50 percent guava solution utilizing 1X10 exponent 8 CFU/ml, too many to count colonies were observed while there was inhibition of growth at 1X10 exponent 5 and 1X10 exponent 4 CFU/ml concentrations. Thus, it could then be probable that the MIC of lyophilized guava extract is 50 percent using bacterial concentrations ranging from 10 exponent 8 to 10 exponent 6 CFU/ml. However, colony formation was observed for 2 mg vancomycin utilizing 1X10 exponent 4 CFU/ml.CONCLUSION: Fifty percent (50 percent) solution of the lyophilized leaf crude aqueous extract inhibited the growth of methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus. The efficacy of guava as an antimicrobial agent on both MRSA and MSSA strains is greater than vancomycin but lower than fusidic acid. Based on the in vitro results, guava can be considered as a good alternative medication for Staphylococcal infection especially with drug resistant Staphylococcus aureus strains. MIC of guava extract was confirmed to be 50 percent utilizing bacterial concentrations ranging from 1X10 exponent 8 and 1X10 exponent 6 CFU/ml. (Author)