Identifying gram-positive cocci in dermatoscopes and smartphone adapters using MALDI-TOF MS: a cross-sectional study

Abstract Background: The increasingly frequent use of dermoscopy makes us think about the possibility of transfer of microorganisms, through the dermatoscope, between doctor and patients. Objectives: To identify the most frequent gram-positive cocci in dermatoscopes and smartphone adapters, as well as the resistance profile, and to evaluate the factors associated with a higher risk of bacterial contamination of the dermatoscopes. Methods: A cross-sectional study was carried out with 118 dermatologists from Porto Alegre/Brazil between September 2017 and July 2018. Gram-positive cocci were identified by MALDI-TOF MS and habits of use of the dermatoscope were evaluated through an anonymous questionnaire. Results: Of the dermatoscopes analysed, 46.6% had growth of gram-positive cocci on the lens and 37.3% on the on/off button. The microorganisms most frequently found were S. epidermidis, S. hominis and S. warneri. Attending a hospital, using the dermatoscope at the hospital, with inpatients and in the intensive care unit were significantly associated with colonisation by gram-positive cocci. The highest resistance rates were observed for penicillin, erythromycin and sulfamethoxazole-trimethoprim. Study limitations: The non-search of gram-negative bacilli, fungi and viruses. Moreover, the small number of adapters did not make it possible to better define if the frequency differences were statistically significant. Conclusion: Coagulase-negative staphylococci were frequently identified. S. aureus was detected only on the lens.

Is it possible to perform bacterial identification and antimicrobial susceptibility testing with a positive blood culture bottle for quick diagnosis of bloodstream infections?

Abstract INTRODUCTION: Bloodstream infections can be fatal, and timely identification of the etiologic agent is important for treatment. METHODOLOGY: An alternative method, consisting of direct identification and susceptibility testing of blood culture bottles using the automated VITEK 2® system, was assessed. RESULTS: All 37 of the Gram-negative bacilli (GNB) identifications and 57.1% of the 28 Gram-positive cocci (GPC) identifications matched those obtained with standard methods. In susceptibility testing, the agreement was greater than 90%. CONCLUSIONS: This alternative methodology may assist in the early identification and susceptibility testing of GNB. Further research is necessary to develop appropriate methods for GPC.

Resistencia a antibióticos de última línea en cocos Gram positivos: la era posterior a la vancomicina / Resistance to "last resort" antibiotics in Gram-positive cocci: The post-vancomycin era

En los últimos años se han desarrollado nuevas alternativas para el tratamiento de infecciones por patógenos Gram positivos multirresistentes, entre los cuales Staphylococcus aureus resistente a la meticilina (SARM) y los enterococos resistentes a la vancomicina (ERV) se consideran un verdadero reto terapéutico, y aunque el uso de la vancomicina en infecciones graves causadas por SARM ha generado serias dudas en los últimos años, continúa siendo escasa la información clínica de respaldo al uso de agentes terapéuticos que la superen en eficacia. El linezolid, la daptomicina y la tigeciclina son agentes que tienen actividad contra los cocos Gram positivos y que fueron aprobados e introducidos en la terapia clínica en la década pasada. Además, se han probado o están en las fases finales de desarrollo otros agentes como las cefalosporinas de última generación (ceftarolina y ceftobiprol). El propósito de esta revisión fue describir las nuevas alternativas terapéuticas, particularmente en la era posterior a la vancomicina, y repasar las características químicas más relevantes de los compuestos y su espectro de actividad, haciendo énfasis en sus mecanismos de acción y resistencia.

New therapeutic alternatives have been developed in the last years for the treatment of multidrug-resistant Gram-positive infections. Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are considered a therapeutic challenge due to failures and lack of reliable antimicrobial options. Despite concerns related to the use of vancomycin in the treatment of severe MRSA infections in specific clinical scenarios, there is a paucity of solid clinical evidence that support the use of alternative agents (when compared to vancomycin). Linezolid, daptomycin and tigecycline are antibiotics approved in the last decade and newer cephalosporins (such as ceftaroline and ceftobiprole) and novel glycopeptides (dalvavancin, telavancin and oritavancin) have reached clinical approval or are in the late stages of clinical development. This review focuses on discussing these newer antibiotics used in the "post-vancomycin" era with emphasis on relevant chemical characteristics, spectrum of antimicrobial activity, mechanisms of action and resistance, as well as their clinical utility.

Emergence and control of multidrug resistant organisms in small cities in India: A wake up call.

Context: Urinary tract infections (UTIs) is one of the most common bacterial infections in general practice. Antimicrobial resistance in urinary pathogens, particularly the most common being Escherichia coli, is directly associated with prescribing in primary care. Diagnosis of UTI requires laboratory examination of urine sample in addition to clinical evaluation, which may lead to higher cost of treatment, but the proper treatment of the case that will lead to complete recovery with no recurrence episodes far outweigh the cost issue of microbiological investigation. Even though UTIs are a very common diagnosis, management of this condition is not consistent in general practice. This study was conducted in an effort to see the extent of presence of multi drug resistant organisms in local set up . Aims: To describe the common urine isolates observed in the small cities of India and also to test for drug resistance among them with simple manageable tests in small-scale laboratories. Materials and Methods: A retrospective review was conducted of Gram negative bacilli and Gram positive cocci isolated from the clinical urine samples collected from various hospitals and private practitioners in Shimoga City, Karnataka and Jamshedpur City, Jharkhand. The study period was between November 2011 to January 2012. Results: A total of 788 urine samples were included in the study. It was seen that 55.8% of the total isolated organisms were multidrug resistant (MDR) in Shimoga city, Karnataka and 38.8% of the total isolated organisms were MDR in Jamshedpur city, Jharkhand. Conclusions: Only with the combined efforts of the local laboratories and clinicians, the looming threat of the pandrug resistant organisms in small cities can be avoided. However, more such studies are required from both clinicians and laboratory health care professionals in order to arrive at a common consensus, and uniformity can be brought about in the community regarding prescription practices.

Novel pharmaceutical molecules against emerging resistant gram-positive cocci

INTRODUCTION: methicillin- and also vancomycin (glycopeptide)-resistant Gram-positive organisms have emerged as an increasingly problematic cause of hospital-acquired infections, also spreading into the community. Vancomycin (glycopeptide) resistance has emerged primarily among Enterococci, but the MIC values of vancomycin for the entire Staphylococcus species are also increasing worldwide. MATERIAL AND METHODS: the aim of our review is to evaluate the efficacy and tolerability of newer antibiotics with activity against methicillin-resistant and glycopeptide-resistant Gram-positive cocci, on the ground of our experience at a tertiary care metropolitan Hospital, and the most recent literature evidences in this field. RESULTS: Quinupristin-dalfopristin, linezolid, daptomycin, and tigecycline show an excellent in vitro activity, comparable to the activity of vancomycin and teicoplanin for methicillin-resistant staphylococci, and superior to the one that vancomycin for vancomycin-resistant isolates. Dalbavancin, televancin, and oritavancin are new lipoglycopeptide agents with excellent activity against Gram-positive cocci, and have superior pharmacodynamics properties compared to vancomycin. We review the bacterial spectrum, clinical indications and practical use, pharmacologic properties, and expected adverse events and contraindications associated with each of these novel antimicrobial agents, compared with the present standard of care. DISCUSSION: linezolid activity is substantially comparable to that of vancomycin in patients with methicillin-resistant Staphylococcus aureus (MRSA) pneumonia, although its penetration into the respiratory tract is exceptionally elevated. Tigecycline has activity against both Enterococus species and MRSA; it is also active against a broad spectrum of Enterobacteriaceae and anaerobes, which allows for use intraabdominal, diabetic foot and surgical infections. Daptomycin has a rapid bactericidal activity for ...

Antibacterial activity of root canal filling materials for primary teeth: zinc oxide and eugenol cement, Calen paste thickened with zinc oxide, Sealapex and EndoREZ

This study evaluated in vitro the antibacterial activity of 4 root canal filling materials for primary teeth - zinc oxide and eugenol cement (ZOE), Calen paste thickened with zinc oxide (Calen/ZO), Sealapex sealer and EndoREZ sealer - against 5 bacterial strains commonly found in endodontic infections (Kocuria rhizophila, Enterococcus faecalis, Streptococcus mutans, Escherichia coli and Staphylococcus aureus) using the agar diffusion test (agar-well technique). Calen paste, 1 percent chlorhexidine digluconate (CHX) and distilled water served as controls. Seven wells per dish were made at equidistant points and immediately filled with the test and control materials. After incubation of the plates at 37oC for 24 h, the diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a digital caliper under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (?=0.05). There were statistically significant differences (p<0.0001) among the zones of bacterial growth inhibition produced by the different materials against all target microorganisms. K. rhizophila was inhibited more effectively (p<0.05) by ZOE, while Calen/ZO had its highest antibacterial activity against E. faecalis (p<0.05). S. mutans was inhibited by Calen/ZO, Sealapex and ZOE in the same intensity (p>0.05). E. coli was inhibited more effectively (p<0.05) by ZOE, followed by Calen/ZO and Sealapex. Calen/ZO and ZOE were equally effective (p>0.05) against S. aureus, while Sealapex had the lowest antibacterial efficacy (p<0.05) against this microorganism. EndoREZ presented antibacterial activity only against K. rhizophila and S. aureus. The Calen paste and Calen/ZO produced larger zones of inhibition than 1 percent CHX when the marker microorganism was E faecalis. In conclusion, the in vitro antibacterial activity of the 4 root canal filling materials for primary teeth against bacterial strains...

Este estudo avaliou in vitro a atividade antibacteriana de 4 materiais obturadores de canais radiculares de dentes decíduos - cimento de óxido de zinco e eugenol (OZE), pasta Calen espessada com óxido de zinco (Calen/OZ), cimento Sealapex e cimento EndoREZ - sobre 5 cepas bacterianas comumente encontradas em infecções endodônticas: Kocuria rhizophila, Enterococcus faecalis, Streptococcus mutans, Escherichia coli e Staphylococcus aureus, usando o teste de difusão em ágar (técnica do poço). A pasta Calen, digluconato de clorexidina a 1 por cento (CHX) e água destilada foram usados como controle. Sete poços por placa foram preparados em pontos eqüidistantes e imediatamente preenchidos com os materiais experimentais e controle. Após incubação das placas a 37oC por 24 h, o diâmetro dos halos de inibição do crescimento bacteriano formados ao redor dos poços foi medido (em mm) com um paquímetro digital sob luz refletida. Os dados obtidos foram submetidos à análise de variância e ao pós-teste de Tukey (?=0,05). Com relação à atividade antibacteriana, evidenciaram-se diferenças estatisticamente significantes (p<0,0001) entre os halos de inibição formados pelos diferentes materiais, para todos os microrganismos avaliados. A K. rhizophila foi inibida mais eficazmente pelo OZE (p<0,05), enquanto que o E. faecalis foi inibido mais eficazmente pela Calen/OZ (p<0,05). O S. mutans foi inibido pela Calen/OZ, cimento Sealapex e OZE na mesma intensidade (p>0,05). A E. coli foi inibida mais eficazmente pelo OZE, seguido pela Calen/OZ e pelo cimento Sealapex (p<0,05). O S. aureus foi inibido pela Calen/OZ e OZE na mesma intensidade (p>0,05), e menos intensamente pelo cimento Sealapex (p<0,05). O cimento EndoREZ apresentou atividade antibacteriana apenas frente a K. rhizophila e ao S. aureus. A pasta Calen e a Calen/OZ ocasionaram halos de inibição maiores que a CHX quando o microrganismo indicador foi o E. faecalis. Pode-se concluir que a atividade antibacteriana...

Activity of amikacin, ertapenem, ciprofloxacin and levofloxacin alone and in combination against resistant nosocomial pathogens by time-kill / Actividad letalidad-tiempo de la amicacina, la ertapenema, la ciprofloxacina y la levofloxacina, solas o en combinación, frente a los patógenos nosocomiales

OBJECTIVE: The purpose of this study was to determine the synergistic activity of amikacin/ertapenem, fluoroquinolones (ciprofloxacin and levofloxacin)/ertapenem and amikacin/fluoroquinolones combinations against resistant nosocomial pathogens. METHODS: Time-kill studies were performed over 24 hours using an inoculum of 5 x 106 - 1 x 107 cfu/mL. Antibiotics were tested at the 1 x MIC and 4 x MIC concentrations. RESULTS: At MIC and/or 4 x MIC concentrations, the antibiotic combinations showed additive or synergistic activity against Acinetobacter strains and extended spectrum beta-lactamase producing Klebsiella pneumoniae. In Escherichia coli strains, synergy was seen when amikacin was combined with ertapenem, ciprofloxacin and levofloxacin; ertapenem in combination with fluoroquinolones demonstrated antagonism. In Pseudomonas aeruginosa strains, synergistic effect was exhibited by ertapenem plus amikacin and ertapenem plus fluoroquinolones. The antibiotic combinations showed antagonistic interaction in methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis. CONCLUSION: The antibiotic combinations showed additive or synergistic activity against many gram-negative pathogens.

OBJETIVO: El propósito del presente estudio fue determinar la actividad sinérgica de la amicacina/ ertapenema/fluoroquinolonas (ciprofloxacina y levofloxacina)/ertapenema y amicacina/y combinaciones de fluoroquinolonas frente a patógenos nosocomiales resistentes. MÉTODOS: Se realizaron estudios de letalidad-tiempo por 24 horas, usando un inóculo de 5 x 106 - 1 x 107 cfu/mL. Se probaron antibióticos en concentraciones de 1xCIM y 4xCIM. RESULTADOS: En concentraciones de CIM y/o 4 x CIM, las combinaciones de antibióticos mostraron actividad aditiva o sinergésica frente a las cepas Acinetobacter y Klebsiella pneumoniae productoras de la beta-lactamasa de espectro extendido. En las cepas de Escherichia coli, se observó sinergia cuando se combinó la amicacina con la ertapenema, la ciprofloxacina y la levofloxacina; la ertapenema en combinación con las fluoroquinolonas demostró antagonismo. En las cepas de Pseudomonas aeruginosa, se puso de manifiesto un efecto sinergésico al sumar la ertapenema con amicacina y la ertapenema con fluoroquinolonas. Las combinaciones antibióticas mostraron interacción antagonística en Staphylococcus aureus resistente a la meticilina y Enterococcus faecalis resistente a la vancomicina. CONCLUSIÓN: Las combinaciones antibióticas mostraron actividad aditiva o sinergésica frente a muchos patógenos gram-negativos.

Antibiotic resistance and trend of urinary pathogens in general outpatients from a major urban city

OBJECTIVE: We assessed the antimicrobial resistance patterns of pathogens responsible for urinary tract infections (UTI) in outpatients in São Paulo, Brazil, as well as the Escherichia coli antimicrobial resistance trend. MATERIALS AND METHODS: Outpatients urine cultures were collected from January 2000 to December 2003. Statistical analysis considered positive results for one bacterial species with colony count > 100,000 CFU/mL. Stratification was done on age group and gender. Statistical tests used included chi-square and the chi-square test for trend to evaluate differences between susceptibility rates among age groups and ordering in the E. coli resistance rates per year, respectively. RESULTS: There were 37,261 positive results with Enterobacteriaceae isolated in 32,530 (87.3 percent) and Gram-positive cocci in 2,570 (6.9 percent) cultures. E. coli had the highest prevalence (71.6 percent). Susceptibility tests were performed in 31,716 cultures. E. coli had elevated resistance rates (> 30 percent) to ampicillin, trimethoprim-sulfamethoxazole, and tetracycline. Significant differences between age groups and ordering among years were observed. CONCLUSIONS: The use of trimethoprim-sulfamethoxazole is precluded in the population studied due to elevated resistance rates (> 30 percent) among most prevalent pathogens. Significant resistance rate differences among age groups and years were observed, particularly for fluoroquinolones. Fluoroquinolones should be used with caution. Nitrofurantoin should be used as empirical therapy for primary, non-complicated urinary tract infections.

Profile of antimicrobial resistance of bacteria isolated from cockroaches (Periplaneta americana) in a Brazilian health care institution

Cockroaches carry microorganisms to sterilized materials, equipment and non-contaminated food in hospitals and in homes. Hence, they are regarded as major microbial vectors. We isolated and identified microorganisms from living cockroaches captured from a Brazilian health care institution and we determined the antimicrobial susceptibility profile of the isolates. Following collection, cockroaches were immobilized at 4°C for 10 to 20 minutes, immersed in 0.8 percent saline solution and then homogenized. Next, the suspension was seeded in culture media: brain and heart agar infusion, MacConkey agar, Naito agar, and they were incubated for up to 48 hours at 37°C. Sabouraud agar cultures were incubated at ambient temperature. The microbial colonies were analyzed with a stereomicroscope to count and phenotypically identify the colony-forming units (cfu). The discdiffusion method was used to determine the profile of susceptibility to antimicrobials. Among the 103 cockroaches analyzed, fungi were found in 97 percent, enterobacteria in 74.6 percent and coagulase-negative staphylococci (CNS) in 25.40 percent. Among the enterobacteria, 96 percent were resistant to gentamicin, 84 percent to ampicillin, 75.3 percent to caphalothin, 66.7 percent to ampicillin-sulbactam, 50 percent to aztreonam and 30 percent to chloramphenicol. Among the CNS, 61 percent were resistant to oxacillin. We concluded that cockroaches carry organisms associated with nosocomial infections and that are resistant to antimicrobials. This fact contributes to the epidemiological chain, complicating therapeutics, and consequently, medical costs are increased.

Influence of sodium hypochlorite-based irrigants on the susceptibility of intracanal microbiota to biomechanical preparation

This study evaluated the microbiological conditions of root canals, using smears and culture from anterior teeth and premolars with necrotic pulps associated with chronic periapical pathologies, before and after biomechanical preparation (BMP). During double-flared instrumentation, 1, 2.5 and 5 percent sodium hypochlorite (NaOCl)-based irrigants were used in 3 groups: GI (n=39), GII (n=36) and GIII (n=36), respectively. Before BMP, all cultures were positive and the smears showed microbiologically diverse morphotypes, including fusiforms, pleomorphic, rods, cocci and filaments. Quantitetively, 20, 20 and 23 morphotypes were identified in GI, GII and GIII, respectively). After BMP, the percentages of negative cultures in GI, GII and GIII were 74.2 percent, 86.3 percent and 93.4 percent (p>0.05) and the number of morphotypes decreased to 14, 15 and 5, respectively. All teeth with 2 root canals and/or associated fistulas were microbiologically negative after BMP, regardless of irrigant concentration. Gram-negative morphotypes were more susceptible to the action of irrigants. After irrigation with 5 percent NaOCl, only structural arrangements consisting of Gram-positive cocci and bacilli persisted. Thus, BMP plus 5 percent NaOCl offered the best antiseptic potential because in the few positive cultures a significant reduction in the number of microbiological morphotypes was also shown (p<0.05).

Este estudo avaliou as condições microbiológicas dos canais radiculares, por meio de esfregaços e culturas de dentes anteriores e pré-molares com necrose pulpar associada à radiolucidezes periapicais, antes e após o preparo biomecânico (PBM). Utilizou-se a técnica de instrumentação biescalonada coadjuvada por soluções de hipoclorito de sódio (NaOCl) a 1, 2,5 ou 5 por cento nos grupos I (n=39), II (n=36) e III (n=36), respectivamente. Antes do PBM havia 100 por cento de culturas positivas e os esfregaços proveram diversificados morfotipos microbiológicos, sendo 20, 20 e 23 nos grupos I, II e III, respectivamente. Após o PBM, o percentual de culturas negativas nos grupos I, II e III foi 74,2 por cento, 86,3 e 93,4 por cento (p>0,05) e a incidência de morfotipos declinou para 14, 15 e 5, respectivamente. Todos os dentes birradiculados e/ou portadores de fístulas apresentaram-se microbiologicamente negativos após o PBM, independentemente do irrigante utilizado. Os morfotipos Gram-negativos foram mais suscetíveis à ação do PBM. Após o PBM persistiram apenas cocos e bacilos Gram-positivos no grupo III. Portanto, o PBM coadjuvado por solução de NaOCl a 5 por cento, proporcionou o melhor desempenho anti-séptico, pois, nas poucas culturas positivas, houve também significativa redução do número de morfotipos microbiológicos (p<0.05).

A comparison of the antimicrobial resistance patterns of gram-positive cocci isolated from community-private and university-affiliated hospitals from Puerto Rico

The antimicrobial resistance patterns of 2,462 selected Gram-positive cocci obtained from three Community-Private Hospitals (CPH) and three University-Affiliated Hospitals (UAH) were evaluated utilizing the institutions' antimicrobial susceptibility reports for the year 2000. The objectives of this study were: 1) to evaluate the in vitro resistance to selected standard antibiotics of Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium and Streptococcus pneumoniae clinical isolates, and 2) to compare the antimicrobial resistance patterns between community-private (CPH) and university-affiliated hospitals (UAH). Staphylococcus aureus was the most common Gram-positive isolated organism in CPH (63.3 per cent) followed by E. faecalis (31.0 per cent). In UAH, the most prevalent cocci were E. faecalis (51.7 per cent) followed by S. aureus (43.9 per cent). Enterococcus faecium represented 2.3 per cent and 4.4 per cent of CPH and UAH isolates, respectively. Streptococcus pneumoniae represented 3.4 per cent of the total Gram-positive isolates from CPH, no S. pneumoniae was reported in UAH. The antimicrobial susceptibility results showed that for Staphylococcus aureus there was a statistically significant higher resistance to methicillin and thrimethoprim sulfamethoxazole in UAH, while resistance to erythromycin was significantly higher in CPH. There was no difference in the resistance of S. aureus to other antimicrobial agents between hospitals groups. A statistically significant resistant to vancomycin was found between enterococcal isolates from UAH (43 per cent) and CPH (12.7 per cent). High-level aminoglycoside resistance (HLAR) was observed among UAH enterococcal isolates with E. faecium showing a higher resistance than E. faecalis, no data for HLAR in CPH could be obtained. For pneumococci 46 per cent of CPH isolates were resistant to penicillin. In summary, there are important differences in the prevalence and antimicrobial resistance between the Gram-positive bacteria isolated from community and teaching hospitals.

Prospective study using standardized methodology for antimicrobial susceptibility of gram-positive cocci isolated from the Puerto Rico Medical Center

The Gram-positive cocci (GPC), Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis and Enterococcus faecium, have become important causes of community and nosocomial-acquired infections. The prevalence of multiple resistant isolates to standard antimicrobial drugs has significantly increased over the past decades. Few prospective studies have been performed in Puerto Rico (PR) concerning the GPC antimicrobial susceptibilities pattern. The purpose of this study was to evaluate the in vitro susceptibility of GPC clinical isolates from PR to selected standard antibiotics and to the new antimicrobial agents, linezolid (LZ), quinupristin/dalfopristin (Q/D) and gemifloxacin (GM). The in vitro susceptibility utilizing disk diffusion and Etest methods to selected antibiotics was determined for a total of 429 isolates obtained during a period of 5 months from the Puerto Rico Medical Center Bacteriology Laboratory. The distribution of GPC collected was as follows: 213 S. aureus isolates, 162 E. faecalis, 16 E. faecium and 38 S. pneumoniae. The results of the susceptibility test demonstrated: 1) that in S. aureus, 100 per cent of the isolates were susceptible to vancomycin (VAN), LZ and Q/D; 93 per cent to GM; and 61 per cent to methicillin/oxacillin; 2) in S. pneumoniae, 100 per cent were susceptible to LN and GM; 87 per cent to Q/D; and 53 per cent to penicillin; 3) in E. faecalis, 99 per cent were susceptible to ampicillin; 93 per cent to LZ; 79 per cent to GM; 78.6 per cent to VAN; and 0 per cent to Q/D. Sixty eight and 66 per cent of the E. faecalis isolates were susceptible to gentamicin and streptomycin respectively; and 4) in E. faecium, 100 per cent were susceptible to LZ; 94 per cent to Q/D; 69 per cent to GM; 37.5 per cent to VAN and 20 per cent to ampicillin. In E. faecium isolates, 50 per cent and 31 per cent were susceptible to gentamicin and streptomycin, respectively. Of the vancomycin resistant enterococci, 88.9 per cent and 21 per cent of E. faecium and faecalis showed VanA phenotypic resistance, respectively...

Vigilancia de susceptibilidad de cocáceas grampositivas a betalactámicos, glicopéptidos y otros antimicrobianos / Surveillance of gram positive cocci susceptibility to betalactamics, glycopeptides and other antimicrobials

Background: During the last decade, there has been a progressive increase in the resistance of gram (+) cocci to betalactamics and other antimicrobials. Therefore, vancomycin and teicoplanin have incorporated as alternative antimicrobial drugs. Aim: To assess the susceptibility of gram (+) cocci to different antimicrobials including vancomycin and teicoplanin. Material and methods: We studied 447 strains of gram (+) cocci coming from ambulatory and hospitalized patients. These included 308 enterococcus sp strains, 99 staphycoccus aureus strains and 40 coagulase negative staphylococci strains. Enterococci susceptibility was measured using minimal inhibitory concentrations in agar and that of staphylococci, through diffusion. Susceptibility to vancomycin and teicoplanin was measured using minimal inhibitory concentrations in all strains. Results: Enterococcus faecalis was 100 percent susceptible to ampicillin, penicillin, vancomycin and teicoplanin, 23 percent susceptible to tetracyclin and 47 percent to chloramphenicol. Susceptibility of E faecium was 61 percent to penicillin, 49 percent to chloramphenicol, 41 percent to tetracyclin, 100 percent to vancomycin and teicoplanin. Of 19 enterococcus spp strains, 90 percent were susceptible to ampicillin, 80 percent to penicillin, 55 percent to chloramphenicol and 45 percent to tetracyclin. Only one E casseiflavus strain had a low level resistance to vancomycin and was susceptible to teicoplanin. No staphylococcus aureus strain was resistant to vancomycin or teicoplanin. Conclusions: A permanent surveillance of gram (+) cocci antimicrobial susceptibility is required to update therapeutic schemes

Rapid diagnosis of anaerobic gram-positive cocci by salt tolerance.

The maximum salt tolerance was 2.5% in cases of Peptostreptococcus anaerobius and Peptococcus prevotii, 3% in Ruminococcus albus, 4% in Acidaminococcus fermentans, Peptococcus niger and Megasphaera elsdenii and 5% in Peptococcus magnus. The biochemical tests being largely inactive and time consuming the findings of salt tolerance if combined with those of morphological data provide clue to the rapid identification of Gram-positive anaerobic cocci.

Teicoplanina: uma nova opçäo para os gram-positivos / Teicoplanin: a new option to the gram-positives

Os autores fazem uma revisao da literatura e analisam as atividades da Teicoplanina em comparaçao principalmente com a Vancomicina. Ficou evidente que o espectro de açao destes dois fármacos é semelhante. A Teicoplanina mostrou-se eficaz contra a grande maioria dos cocos Gram-positivos. Porém, devido ao seu elevado custo, seu uso fica restrito a infecçoes hospitalares graves por Staphylococcus resistentes à Vancomicina.

Identification of gram positive cocci isolated from urine.

A total of 195 strains of Gram positive cocci isolated from urine, in pure culture and in counts of > 10(3) colony forming units/ml, during January-September 1992, were speciated using schema recently described by Facklam and Washington, and Kloos and Lambe. Seventy three (85%) of the 86 enterococci were identified as Enterococcus faecalis while 11 (13%) were E. faecium. Eighteen (29%) of the 62 staphylococcal isolates were Staphylococcus aureus; 20 (45%) of the 44 coagulase negative staphylococci were speciated as Staph. haemolyticus. Of the 47 strains of beta haemolytic streptococci isolated, 45 (96%) were group B; one was group G and the other group F. Our results show the diverse species of Gram positive cocci associated with bacteriuria and the need to speciate them in a diagnostic laboratory. In the context of a larger number of tests required for the speciation of Gram positive cocci, we recommend a simplified scheme which we found feasible on a routine basis.

Antibacterial susceptibility of anaerobes by agar dilution method.

Of the 9 antibacterials, vancomycin alone at its break-point (optimum blood level) revealed highest (93.3%) efficacy on Gram-positive cocci. The remarkable activity of carbenicillin, chloramphenicol and vancomycin on Gram-positive cocci (95.4 to 96.9%), carbenicillin and chloramphenicol on Gram-positive bacilli (94.8% to 98.2%) and chloramphenicol on Gram-negative bacilli (95.4%) was noted by increasing their concentrations 1.5 to 2.5 times above their break-points. These (and even higher) concentration, however, showed relatively lower efficacy of metronidazole, rifampicin, penicillin, clindamycin and erythromycin on Gram-positive cocci (76 to 84.1%), rifampicin, tetracycline, erythromycin, clindamycin and vancomycin on Gram-positive bacilli (81 to 87.9%) and clindamycin, metronidazole, rifampicin and carbenicillin in Gram-negative bacilli (72.7 to 84%). By and large, rifampicin, chloramphenicol and carbenicillin are also quite effective (72.1 to 75.1%) at lower concentration.