Actividad in vitro del tedizolid y de antibióticos de comparación en aislamientos de Staphylococcus aureus resistentes a meticilina en infecciones de piel y tejidos blandos en siete hospitales de Colombia / In vitro activity of tedizolid and other comparator drugs in methicillin-resistant Staphylococcus aureus isolates in skin and soft tissue infections in seven Colombian hospitals

Introducción. Staphylococcus aureus resistente a meticilina (SARM) causa infecciones graves de la piel y los tejidos blandos en los hospitales y, en los últimos años, en la comunidad. El tedizolid es una nueva oxazolidinona cuya potencia in vitro ha demostrado ser mayor que la del linezolid frente a este microorganismo. Objetivo. Conocer la actividad antimicrobiana del tedizolid y de algunos antibióticos de comparación en aislamientos de SARM causante de infecciones de piel y tejidos blandos en hospitales de Colombia. Materiales y métodos. Se hizo un estudio multicéntrico prospectivo y descriptivo a lo largo de doce meses en siete hospitales de tercer nivel de Colombia. Se recolectaron aislamientos de SARM de pacientes adultos con infección de piel y tejidos blandos. Se determinó la concentración inhibitoria mínima (CIM) mediante la técnica de ETEST® (bioMérieux) del tedizolid, el linezolid, la vancomicina, la daptomicina, el trimetoprim-sulfametoxazol y la clindamicina. Resultados. Se obtuvieron aislamientos de SARM de 102 pacientes, de los cuales 56 (54,9 %) eran hombres; el promedio de edad fue de 46,8 años. La infección tuvo origen en la comunidad en 77 casos (75,4 %). El tipo de muestra que predominó fue el absceso (69 pacientes: 67,6 %). Todos los aislamientos fueron sensibles a tedizolid, linezolid, daptomicina, trimetoprim-sulfametoxazol y vancomicina. La actividad in vitro del tedizolid fue mayor que la del linezolid. Los intervalos de la CIM del tedizolid oscilaron entre 0,125 µg/ml y 0,5 µg/ml en tanto que los del linezolid fluctuaron entre 1 µg/m y 2 µg/ml. Conclusiones. Las cepas circulantes de SARM en Colombia presentaron una gran sensibilidad al tedizolid, por lo cual sería una alternativa terapéutica para las infecciones de piel y tejidos blandos en nuestro medio.

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) causes severe skin and soft tissue infections in hospitals and, more recently, in the community. Tedizolid is a new second-generation oxazolidinone derivative having greater in vitro potency than linezolid against this type of microorganism. Objectives: To evaluate the antimicrobial activity of tedizolid and other comparator antibiotics in MRSA isolates causing skin and soft tissue infections in Colombian hospitals. Materials and methods: We conducted a prospective, multi-center descriptive study in seven tertiary-level hospitals in Colombia along a 12-month period. MRSA isolates were collected from adult patients with skin and soft tissue infections. Tedizolid, linezolid, vancomycin, daptomycin, trimethoprimsulfamethoxazole, and clindamycin minimum inhibitory concentration (MIC) was determined by ETEST® (bioMérieux). Results: MRSA isolates were obtained from 102 patients with an average age of 46.8 years of whom 56 (54.9%) were men. Infection was community-acquired in 77 cases (75.4%). Abscess-related samples predominated (69 patients: 67.6%). All isolates were susceptible to tedizolid, linezolid, daptomycin, trimethoprim-sulfamethoxazole, and vancomycin. Tedizolid had greater in vitro activity than linezolid. Tedizolid MIC intervals ranged from 0.125 µg/mL to 0.5 µg/mL while those of linezolid ranged from 1µg/mL to 2µg/mL. Conclusions: MRSA strains circulating in Colombia are highly susceptible to tedizolid and can be considered a therapeutic alternative for hospitals and/or community-acquired skin and soft tissue infections.

Onychomatricoma: a tumor unknown to dermatologists

A sixty-one year old white female was referred to the Dermatology Department to treat an ingrown nail in the inner corner of the left hallux. Examination of the entire nail unit showed the presence of xanthonychia in the outer corner besides thickening and increase in the transverse curvature of the nail plate. Dermoscopy and nuclear magnetic resonance of the free edge of the nail plate detected characteristic signs of onychomatricoma, a diagnosis that was later confirmed by anatomopathological exam.

In vitro susceptibility to methicillin, vancomycin and linezolid of staphylococci isolated from bloodstream infections in eastern Turkey

Staphylococcus species are one of the major causes of bacterial bloodstream infections. Multi-resistant staphylococci infections are major therapeutic problems. This study was aimed to detect methicillin, linezolid and vancomycin susceptibilities of Staphylococcus isolates. A total of 870 Staphylococcus strains isolated from blood cultures of hospitalized patients with BSI. Antimicrobial susceptibilities of methicillin, linezolid and vancomycin were detected according to the Clinical and Laboratory Standards Institute (CLSI). A total of 771 (88.6%) isolates were coagulase-negative staphylococci (CoNS). 700 (80.5%) isolates were methicillin-resistant (MR) and 170 (19.5%) were methicillin-susceptible (MS). All the MS isolates were also susceptible to linezolid. However 15 (1.7%) of MR strains were resistant to linezolid. The minimum inhibitory concentration range for the linezolid-resistant isolates by Etest was 6-32 µg/mL. The difference between linezolid susceptibilities for MS and MR staphylococci was not quite statistically significant (p = 0.052). There was no statistically significant difference between S. aureus and CoNS isolates for linezolid susceptibility. All of the isolates were susceptible to vancomycin. In conclusion, linezolid is currently an efficient option for the treatment of methicillin-resistant staphylococci infections.

Colistin and anti-Gram-positive bacterial agents against Acinetobacter baumannii

Introduction Acinetobacter baumannii has attained an alarming level of resistance to antibacterial drugs. Clinicians are now considering the use of older agents or unorthodox combinations of licensed drugs against multidrug-resistant strains to bridge the current treatment gap. We investigated the in vitro activities of combination treatments that included colistin with vancomycin, norvancomycin or linezolid against multidrug-resistant Acinetobacter baumannii. Methods The fractional inhibitory concentration index and time-kill assays were used to explore the combined effects of colistin with vancomycin, norvancomycin or linezolid against 40 clinical isolates of multidrug-resistant Acinetobacter baumannii. Transmission electron microscopy was performed to evaluate the interactions in response to the combination of colistin and vancomycin. Results The minimum inhibitory concentrations (MICs) of vancomycin and norvancomycin for half of the isolates decreased below the susceptibility break point, and the MIC of linezolid for one isolate was decreased to the blood and epithelial lining fluid concentration using the current dosing regimen. When vancomycin or norvancomycin was combined with subinhibitory doses of colistin, the multidrug-resistant Acinetobacter baumannii test samples were eradicated. Transmission electron microscopy revealed that subinhibitory doses of colistin were able to disrupt the outer membrane, facilitating a disruption of the cell wall and leading to cell lysis. Conclusions Subinhibitory doses of colistin significantly enhanced the antibacterial activity of vancomycin, norvancomycin, and linezolid against multidrug-resistant Acinetobacter baumannii. .

Sensibilidad antimicrobiana in vitro en aislamientos de Enterococcus faecalis y Enterococcus faecium obtenidos de pacientes hospitalizados / In vitro antimicrobial susceptibility in Enterococcus faecalis and Enterococcus faecium isolated from hospitalized patients

Introducción. Actualmente se considera a Enterococcus spp. como uno de los agentes de infección hospitalaria más importantes, siendo su resistencia a los antibióticos un problema importante en los centros de salud. Objetivos. Caracterizar la resistencia antimicrobiana en 50 cepas de Enterococcus spp. aisladas de muestras clínicas de pacientes hospitalizados . Materiales y métodos. Se llevó a cabo un estudio de tipo descriptivo observacional de corte transversal en 50 aislamientos clínicos de estas especies microbianas. Se trabajó un aislamiento por paciente. La identificación y la sensibilidad a los antibióticos se realizaron por métodos automatizados y convencionales. El análisis fenotípico de los mecanismos de resistencia a glucopéptidos se hizo según las recomendaciones de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. Resultados. De 50 aislamientos, 30 (60,0 %) y 20 (40,0 %) pertenecían a las especies de Enterococcus faecalis y Enterococcus faecium, respectivamente. La resistencia global expresada por este género fue de 38/50 (76,0 %) para ampicilina; 33/50 (66,0 %) para gentamicina de alto nivel; 34/50 (68,0 %) para estreptomicina de alto nivel; 26/50 (52,0 %) para ciprofloxacina; 4/50 (8,0 %) para linezolid; 17/50 (34,0 %) para teicoplanina; 25/50 (50,0 %) para vancomicina; 31/50 (62,0 %) para minociclina; 34/50 (68,0 %) para tetraciclina y 9/50 (18,0 %) para nitrofurantoina. Frente a los glucopéptidos, 25/50 (50,0 %) y 10/50 (20,0 %) de los aislamientos presentaron los mecanismos Van A y Van B, respectivamente. Conclusiones. Podemos concluir que la mayoría de las veces, las cepas aisladas en el Hospital Hermanos Ameijeiras mostraron porcentajes de resistencia por encima de lo reportado en la literatura científica consultada. El alto porcentaje de cepas con resistencia a la vancomicina podría influir en la aparición de otros gérmenes Gram positivos con resistencia a este fármaco. Se reporta por primera vez en un hospital cubano resistencia de E. faecium a linezolid.

Introduction: Enterococcus spp is currently considered as one of the most important nosocomial pathogens . The antibiotic resistance of this group of bacteria is a particularly important problem in health centers. Objective: To characterize the antibiotic resistance of 50 Enterococcus spp strains isolated from hospitalized patients clinical samples. Materials and methods: We conducted a cross-sectional descriptive observational study in 50 clinical isolates of Enterococcus spp. Only one isolate per patient was analyzed . The identification and antibiotic susceptibility were studied by conventional and automated methods . The phenotypic analysis of glycopeptide resistance mechanisms was performed as recommended by the Spanish Society of Clinical Microbiology and Infectious Diseases . Results: Of 50 isolates obtained from clinical samples, 30 ( 60.0%) belonged to Enterococcus faecalis and 20 (40.0 %) to Enterococcus faecium . The global resistance expressed by this genre was as follows: Ampicillin, 38/50 ( 76.0%); high-level gentamicin, 33/50 ( 66.0%); high-level streptomycin, 34/50 (68.0 %) ; ciprofloxacin, 26/50 (52.0 %); linezolid, 4/50 (8.0 %); teicoplanin, 17/50 ( 34.0%); vancomycin, 25/50 (50.0 %); minocycline, 31/50 ( 62.0%); tetracycline, 34/50 (68.0 %); nitrofurantoin, 9/50 ( 18.0%). As regards glycopeptides, 25/50 (50.0%) showed a Van A mechanism and 10/50 (20.0 %) a Van B mechanism . Conclusions: The isolates obtained at Hospital Hermanos Ameijeiras showed higher resistance rates than those reported in the consulted literature. The high percentage of vancomycin-resistant strains might have influenced the development of other Gram-positive bacteria resistant to this drug. This is the first report on Enterococcus faecium resistant to linezolid in a Cuban hospital.

Neumonía secundaria a Staphylococcus aureus resistente a la meticilina / Pneumonía associated with Staphylococcus aureus methicillin resistant

Pneumonia associated with Staphylococcus aureus resistant to methicillin has emerged as an important pathogen in children without established risk factors and prevalence worldwide is increasing. This organism is capable of causing severe invasive disease with there commitment to optimal and timely treatment should be established promptly. The decision to start treatment is based on empirical knowledge of the local prevalence of susceptibility pattern, the severity of the infection and the risk factors and the host. Therapeutic alternatives primarily in children include vancomycin, clindamycin, linezolid, and trimethoprim/sulfamethoxazole.

La neumonía asociada a Staphylococcus aureus resistente a la meticilina ha emergido como un patógeno importante en niños sin establecerse factores de riesgo y su prevalencia a nivel mundial va en ascenso. Este organismo es capaz de causar enfermedad invasiva con compromiso severo de allí que el tratamiento óptimo y oportuno debe de establecerse con prontitud. La decisión de iniciar tratamiento empírico se basa en el conocimiento de la prevalencia local del patrón de susceptibilidad, la severidad de la infección y los factores e riesgo del huésped. Las alternativas terapéuticas en niños incluyen fundamentalmente vancomicina, clindamicina, linezolid y trimetropin/sulfametoxazol.

Caracterização molecular dos mecanismos de resistência à linezolida em estafilococos coagulase-negativos e estudo da estabilidade do fenótipo resistente / Linezolid resistance in negative-coagulase staphylococci: characterization and stability of resistant phenotype

Linezolida foi o primeiro fármaco da classe das oxazolidinonas a ser aprovado para o uso clínico. Esta nova oxazolidinona inibe a síntese protéica impedindo a formação do complexo de iniciação formado pelo mRNA, tRNA f-Met e a subunidade 50S do ribossomo bacteriano. Embora a resistência à linezolida possa ser mediada pelo produto do gene cfr ou por mutações nas proteínas ribossômicas L3, L4 e L22, o mecanismo de resistência mais comum envolve mutações no domínio V do gene rRNA 23S. Entre março de 2008 a dezembro de 2011, 38 cepas de estafilococos coagulase-negativos (SCNs) resistentes à linezolida (20 S. epidermidis, 14 S. haemolyticus, 3 S. hominis e 1 S. warneri) isoladas de hemoculturas e pontas de cateter de pacientes internados em dois hospitais terciários do Estado de São Paulo foram incluídas neste estudo para a determinação dos mecanismos de resistência e análise da estabilidade do fenótipo resistente. As cepas de SCNs apresentaram altos níveis de resistência à linezolida (CIMs de 16-128 µg/ml) e foram multi-resistentes, permanecendo sensíveis à vancomicina e teicoplanina. A mutação G2576T foi identificada no domínio V do gene rRNA 23S em todas as cepas de SCNs, exceto em uma cepa de S. haemolyticus. O gene cfr e mutações nas proteínas L4 e L22 não foram detectados. Em relação à proteína L3, todas as cepas de S. epidermidis do hospital A, incluindo a cepa controle sensível à linezolida, apresentaram a substituição Leu101Val, sugerindo que essa mutação seja um marcador clonal dessa população sem envolvimento com a resistência à linezolida. A única cepa proveniente do hospital B (S. epidermidis) foi selvagem para essa proteína ribossômica. Somente uma cepa de S. haemoyticus teve uma mutação no gene rplC, resultando na alteração Val154Leu. Em S. hominis, a mutação Phe147Ile foi identificada em uma cepa, enquanto a associação de Gly139Arg e Met156Thr foi observada nas outras duas cepas dessa espécie. A identificação dessas mutações na proteína L3 de...

Linezolid was the first agent of the oxazolidinone class to be introduced clinically. This oxazolidinone inhibits protein biosynthesis by preventing the formation of the initiation complex that consists of the mRNA, the f-Met tRNA and the 50S subunit of the ribosome. Although linezolid resistance has been mediated by the cfr-encoded product or by ribosomal proteins (L3, L4 and L22), the most common mechanism of resistance involves mutations in the central loop of domain V of the 23S rRNA gene. From March 2008 to December 2011, 38 coagulase-negative staphylococci (CNS) strains (20 S. epidermidis, 14 S. haemolyticus, 3 S. hominis e 1 S. warneri) exhibiting resistance to linezolid were isolated from blood and catheter cultures from patients in two tertiary care hospitals in the State of São Paulo and were included in this study for the ascertainment of the resistance mechanisms to this antimicrobial agent and for the analysis of the stability of this resistance. The strains exhibited high-level resistance to linezolid (MICs 16-128 µg/ml) and all were multidrug resistant, remaining susceptible to vancomycin and teicoplanin. The G2576T mutation in domain V region of 23S rRNA was identified in all isolates, except in a linezolid-resistant S. haemolyticus strain. The cfr gene and mutations in ribosomal proteins L4 and L22 were not detected. Regarding L3 protein analysis, all S. epidermidis strains of hospital A, including the linezolid-susceptible control strain, showed the L3 Leu101Val mutation, suggesting that this alteration is probably not involved in linezolid resistance. The one strain from hospital B (S. epidermidis) was wild-type for this ribosomal protein. Only one S. haemolyticus strain had a mutation in the L3 protein, Val154Leu. Two S. hominis strains showed Gly139Arg/Met156Thr mutations whereas one strain had Phe147Ile in L3 protein. The identification of these mutations in L3 protein of the linezolid-resistant S. haemolyticus and S. hominis strains...

Successful treatment of pulmonary Nocardia farcinica infection with linezolid: case report and literature review

Nocardia infection is rare but potentially fatal. Therapy of Nocardia infection remains difficult. Linezolid, a novel oxazolidinone antibiotic, has proven to be effective, but clinical data are limited. Here we describe a case of a 45-year-old man with pulmonary N. farcinica infection following a liver transplantation. The initial therapy was trimethoprim-sulfamethoxazole, which showed no effect. According to susceptibility test, linezolid was administered with clearly improving the patient's condition. The treatment was stopped for anemia as drug related adverse event, and the therapy lasted for as long as 5 months. At the end of treatment clinical cure was confirmed and anemia reversed after discontinuation of linezolid. We also analyzed the clinical data of previously published reports by literature review, focusing on the efficacy and safety of linezolid treatment for Nocardia infection.

Increasing pathomorphism of pulmonary tuberculosis: an observational study of slow clinical, microbiological and imaging response of lung tuberculosis to specific treatment. Which role for linezolid?

During recent years, a progressive emerging of tuberculosis occurred, related to the overall increased age of general population, primary and secondary (iatrogenic) immunodeficiencies, the availability of invasive procedures, surgical interventions and intensive care supports, bone marrow and solid organ transplantation, and especially the recent immigration flows of people often coming from areas endemic for tuberculosis, and living with evident social-economical disadvantages, and with a reduced access to health care facilities. Since January 2006, at our reference centre we followed 81 consecutive cases of pulmonary tuberculosis, with 65 of them which remained evaluable for the absence of extrapulmonary complications, and a continuative and effective clinical and therapeutic follow-up. The majority of episodes of evaluable pulmonary tuberculosis (49 cases out of 65: 75,4 percent) occurred in patients who immigrated from developing countries. In two patients multiresistant (MDR) Mycobacterium tuberculosis strains were found, while two more subjects (both immigrated from Eastern Europe) suffered from a disease due to extremely resistant (XDR) M. tuberculosis strains. Although enforcing all possible measures to increase patients' adherence to treatment (empowerment, delivery of oral drugs under direct control, use of i.v. formulation whenever possible), over 72 percent of evaluable patients had a very slow clinical, microbiological, and imaging ameliorement (1-6 months), with persistance of sputum and/or bronchoalveolar lavage (BAL) fluid positive for M.tuberculosis microscopy and/or culture for over 1-4 months (mean 9.2±3.2 weeks), during an apparently adequate treatment. When excluding patients suffering from XDR and MDR tuberculosis, in four subjects we observed that off-label linezolid adjunct together with at least three drugs with residual activity against tuberculosis, led to a significantly more rapid clinical-radiological improvement...

The recent evolution of therapeutic weapons against resistant Gram-positive microorganisms

Multiresistant Gram-positive cocci, including Staphylococcus aureus, the group of coagulase-negative staphylococci, Enterococcus faecalis and Enterococcus faecium, as well as Streptococcus pneumoniae and other streptococci, represent emerging pathogens. This issue is especially concerning in the setting of immunocompromised, hospitalized patients, in particular when surgery, invasive procedures, or prosthetic implants are carried out, patients are admitted in intensive care units, or underlying chronic disorders and immunodeficiency are of concern, and broad-spectrum antibiotics are widely used in the environment; moreover, a community spread of resistant Gram-positive cocci has been recognized during recent years. The spectrum of antimicrobials available for an effective management of these relevant infections is significantly threatened by the emerging of methicillin-resistant and more recently glycopeptide-resistant strains. The streptogramine association represented by quinupristin/dalfopristin, the oxazolidinone derivative linezolid, and the recently licensed daptomycin and tigecycline, together with a number of glycopeptides, fluoroquinolones, cephalosporins, and other experimental compounds, represent an effective response. It is due to the innovative mechanisms of action of these compounds, their maintained or enhanced activity against multiresistant pathogens, their effective pharmacokinetic/pharmacodynamic properties, their frequent possibility of synergistic activity with other compounds effective against Gram-positive pathogens, and a diffuse potential for a safe and easy administration, also to compromised patients.

Tuberculosis extensamente resistente (XDR-TB) en Argentina: aspectos destacables epidemiológicos, bacteriológicos, terapéuticos y evolutivos / Extensively resistant tuberculosis (XDR-TB) in Argentina: epidemiology, bacteriology, therapy and outcome

La XDR-TB (resistente a isoniazida, rifampicina, alguna fluoroquinolona y al menos una entre kanamicina, amikacina o capreomicina), ha causado efectos devastadores en pacientes con SIDA y es prácticamente incurable. Se presentan 12 casos de localización pulmonar en pacientes no SIDA. Se trataron con esquemas que incluyeron en todos linezolid y en 9 moxifloxacino, todos negativizaron el examen directo y cultivo del esputo. Nueve pacientes cumplieron criterios de curación, 1 está aún en tratamiento y 2 abandonaron. Ocho pacientes presentaron efectos adversos, en solo 1 caso debió suspenderse la tioridazina. La utilización de linezolid, moxifloxacina y tioridazina han contribuido a la evolución satisfactoria de estos pacientes. Estos fármacos son considerados de utilidad en la serie reportada, debiendo ser utilizados en centros especializados con experiencia en el manejo de la TB MR y XDR-TB.

The XDR-TB (resistant to isoniazid, rifampiN, fluorquinolone and at least of the following: kanamycina, amikacyna or capreomycin), has caused devastating effects in patients with AIDS and is practically incurable. Twelve cases of pulmonary XDR-TB in non AIDS are described. All were treated with schemes that included linezolid in all and moxifloxacin in 9, all respiratory specimens became negative. Nine patients fulfilled healing criteria, 1 is still under treatment and 2 abandoned the therapy. Eight patients presented adverse effects, thioridazine was stopped in only one patient. Linezolid, moxifloxacin and tioridazin contributed to the satisfactory evolution of these patients. These drugs were considered useful in the reported series of cases and should be used in specialized centres with experience in the management of MR TB and XDR-TB.

Vancomycin-resistant van a phenotype Enterococcus faecalis: first case in Minas Gerais state and epidemiological considerations

We report the first case of vancomycin-resistant Enterococcus faecalis with VanA phenotype and vanA genotype isolated from a surgical patient in a general Hospital in Uberlândia, state of Minas Gerais, Brazil.

Successful treatment of vancomycin-resistant enterococcus ventriculitis in a child

Enterococci are an uncommon cause of CNS infection. A 20 month-old boy, diagnosed with hydrocephalus with ventriculoperitoneal shunt and history of lengthy hospitalization and use of wide spectrum antibiotics, was admitted to the pediatric intensive care unit diagnosed with ventriculitis. On the 14th day of empirical antibiotic therapy (vancomycin and meropenem) the child presented fever while the CSF sample culture evidenced vancomycin-resistant Enterococcus faecium. The patient received intravenous linezolid achieving cerebrospinal fluid sterilization. Conclusion: Intravenous linezolid appears to be a safe and effective therapy for vancomycin-resistant enterococcus ventriculoperitoneal shunt infection.

Cost-effectiveness of linezolid versus vancomycin in mechanical ventilation-associated nosocomial pneumonia caused by methicillin-resistant staphylococcus aureus

Linezolid, an oxazolidinone-class antimicrobial agent, is a new drug; its use has frequently been questioned due to its high price. However, recent trials have demonstrated that the use of linezolid in mechanical ventilation-associated nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus (VAP-MRSA) may be justified due to its improved efficacy compared to vancomycin. Price and cost have different magnitudes, and clinical efficacy should always be considered in the decision-making process. Our objective was to determine whether linezolid treatment was more cost-effective than vancomycin for treating VAP-MRSA. METHODOLOGY: Elaboration of an economic model from a metanalysis of previous clinical trials comparing both drugs, through a cost-effectiveness analysis. Costs of the treatments were calculated using Brazilian parameters and were compared to the results obtained in the metanalysis. In order to compare the results with real life conditions, costs were calculated for both name brand and for generic vancomycin. RESULTS: The cost (May/2004) per unit (vial, ampoule or bag) was R$ 47.73 for the name-brand vancomycin, R$ 14.45 for generic vancomycin and R$ 214.04 for linezolid. Linezolid's efficacy in VAP-MRSA according to the metanalysis was 62.2 percent and vancomycin's efficacy was 21.2 percent. The total cost per cured patient was R$ 13,231.65 for the name-brand vancomycin, R$ 11,277.59 for generic vancomycin and R$ 7,764.72 for linezolid. CONCLUSION: Despite the higher price per unit, linezolid was more cost-effective than vancomycin.

Análise de minimização de custos do uso de linezolida vs vancomicina em infecções de pele e partes moles por MRSA / Cost minimization analysis: use of linezolid vs vancomycin for MRSA skin and soft tissues infections

A linezolida é um antibiótico eficaz no tratamento de infecções de pele e de parte moles (IPPM) causadas por S. aureus resistente a meticilina (MRSA); além disso, seu uso pode antecipar a alta, reduzir os custos, minimizar as complicações decorrentes da internação e do uso da via intravenosa. Este estudo compara os tratamentos com linezolida e vancomicina para IPPM-MRSA

Multicenter assessment of the linezolid spectrum and activity using the disk diffusion and Etest methods: report of the Zyvox(R) antimicrobial potency study in Latin America (LA-ZAPS)

Linezolid was the first clinically applied member of the new antimicrobial class called the oxazolidinones. These agents have a powerful spectrum of activity focussed against Gram-positive organisms including strains with documented resistances to other antimicrobial classes. We conducted a multicenter surveillance (Zyvox Antimicrobial Potency Study; ZAPS) trial of qualifying Gram-positive isolates from 24 medical centers in eight countries in Latin America. The activity and spectrum of linezolid was compared to numerous agents including glycopeptides, quinupristin/dalfopristin, beta-lactams and fluoroquinolones when testing 2,640 strains by the standardized disk diffusion method or Etest (AB BIODISK, Solna, Sweden). The linezolid spectrum was complete against staphylococci (median zone diameter, 29 - 32 mm), as was the spectrum of vancomycin and quinupristin/dalfopristin. Among the enterococci, no linezolid resistance was detected, and the susceptibility rate was 93.1 - 96.4. Only the vancomycin-susceptible Enterococcus faecium strains remained susceptible (92.8) to quinupristin/dalfopristin. Marked differences in the glycopeptide resistance patterns (van A versus van B) were noted for the 22 isolates of VRE, thus requiring local susceptibility testing to direct therapy. Streptococcus pneumoniae and other species were very susceptible (100.0) to linezolid, MIC(90) at 0.75 microg/ml. Penicillin non-susceptible rate was 27.7 and erythromycin resistance was at 17.4. Other streptococci were also completely susceptible to linezolid (MIC(90), 1 microg/ml). These results provide the initial benchmark of potency and spectrum for linezolid in Latin American medical centers. Future comparisons should recognize that the oxazolidinones possess essentially a complete spectrum coverage of the monitored staphylococci, enterococci and streptococcal isolates in 2000-2001. This positions linezolid as the widest spectrum empiric choice against multi-resistant Gram-positive cocci, a spectrum of activity greater than available glycopeptides and the streptogramin combination.