Catheter-related bloodstream infection in adult haematology patients:Catheter removal practice and outcome

The aim of the present study was to describe the practice of central venous catheter (CVC) removal and outcomes of catheter-related bloodstream infection (CR-BSI) in adult haematology patients. Patients were identified retrospectively according to diagnosis coding of inpatient episodes and evaluated when, on examination of medical records, there had been evidence of sepsis with strong clinical suspicion that the source was the CVC. Demographic and bacteriological data, as well as therapeutic measures and clinical outcomes, were recorded. One hundred and three patient episodes were evaluated. The most frequent type of CVC was the Hickman catheter and the most frequently isolated pathogen was coagulase-negative staphylococci. Twenty-five percent of episodes were managed with catheter removal. Treatment failure, defined as recurrence of infection within 90 days or mortality attributed to sepsis within 30 days, occurred significantly more frequently in the group managed without catheter removal (52.5% versus 4%, P

Propionibacterium acnes and Staphylococcus lugdunensis Cause Pyogenic Osteomyelitis in an Intramedullary Nail Model in Rabbits

Propionibacterium acnes and coagulase-negative staphylococci (CoNS) are opportunistic pathogens implicated in prosthetic joint and fracture fixation device-related infections. The purpose of this study was to determine whether P. acnes and the CoNS species Staphylococcus lugdunensis, isolated from an "aseptically failed" prosthetic hip joint and a united intramedullary nail-fixed tibial fracture, respectively, could cause osteomyelitis in an established implant-related osteomyelitis model in rabbits in the absence of wear debris from the implant material. The histological features of P. acnes infection in the in vivo rabbit model were consistent with localized pyogenic osteomyelitis, and a biofilm was present on all explanted intramedullary (IM) nails. The animals displayed no outward signs of infection, such as swelling, lameness, weight loss, or elevated white blood cell count. In contrast, infection with S. lugdunensis resulted in histological features consistent with both pyogenic osteomyelitis and septic arthritis, and all S. lugdunensis-infected animals displayed weight loss and an elevated white blood cell count despite biofilm detection in only two out of six rabbits. The differences in the histological and bacteriological profiles of the two species in this rabbit model of infection are reflective of their different clinical presentations: low-grade infection in the case of P. acnes and acute infection for S. lugdunensis. These results are especially important in light of the growing recognition of chronic P. acnes biofilm infections in prosthetic joint failure and nonunion of fracture fixations, which may be currently reported as "aseptic" failure. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Dual functional ionic liquids as antimicrobials and plasticisers for medical grade PVCs

Two ionic liquids, 1-ethylpyridinium docusate (IL1) and tri-n-butyl(2-hydroxyethyl)phosphonium docusate (IL2), were designed and synthesized with the explicit intention of imparting a combination of plasticization and antimicrobial efficacy when incorporated into medical grade poly(vinyl chloride)s (PVCs). The glass transition (T-g) of PVC can be reduced by >20 degrees C on addition of 15 wt% IL2. Both IL1 and IL2 leached to varying extents from the base PVC resins rendering the surface of the PVCs hydrophilic. The antimicrobial activity of both ILs is related to the presence and concentration of both cationic and anionic component of the ILs leached from the PVC and inversely proportional to the extent of PVC gelation. Blends of the PVCs with IL1 displayed antibacterial activity against almost all Gram-positive bacteria tested, including coagulase-negative Staphylococci (CoNS) and methicillin-resistant Staphylococcus aureus (MRSA), but not with IL2 at low concentration in contrast to our previous study when high concentrations of IL2 were used. The more hydrophilic IL1 when added to PVC retards biofilm formation.

Sonication of removed breast implants for improved detection of subclinical infection.

BACKGROUND: Capsular fibrosis is a severe complication after breast implantation with an uncertain etiology. Microbial colonization of the prosthesis is hypothesized as a possible reason for the low-grade infection and subsequent capsular fibrosis. Current diagnostic tests consist of intraoperative swabs and tissue biopsies. Sonication of removed implants may improve the diagnosis of implant infection by detachment of biofilms from the implant surface. METHODS: Breast implants removed from patients with Baker grades 3 and 4 capsular contracture were analyzed by sonication, and the resulting sonication fluid was quantitatively cultured. RESULTS: This study investigated 22 breast implants (6 implants with Baker 3 and 16 implants with Baker 4 capsular fibrosis) from 13 patients. The mean age of the patients was 49 years (range, 31-76 years). The mean implant indwelling time was 10.4 years (range, 3 months to 30 years). Of the 22 implants, 12 were used for breast reconstruction and 10 for aesthetic procedures. The implants were located subglandularly (n = 12), submuscularly (n = 6), and subcutaneously (n = 4). Coagulase-negative staphylococci, Propionibacterium acnes, or both were detected in the sonication fluid cultures of nine implants (41%), eight of which grew significant numbers of microorganisms (>100 colonies/ml of sonication fluid). CONCLUSIONS: Sonication detected bacteria in 41% of removed breast implants. The identified bacteria belonged to normal skin flora. Further investigation is needed to determine any causal relation between biofilms and capsular fibrosis.

Characteristics of infections associated with external ventricular drains of cerebrospinal fluid.

OBJECTIVES: Manifestations of external ventricular drain (EVD) - associated infections overlap with those of the underlying neurosurgical conditions. We analyzed characteristics of EVD-associated infections. METHODS: We included patients aged ≥18 years with EVD-associated infections from 1997 to 2008, using modified CDC criteria for nosocomial infections. Hospital charts were reviewed retrospectively and the in-hospital outcome was evaluated. RESULTS: Forty-eight patients with EVD-associated infections were included (median age, 52 years, range 20-74 years). The median EVD-indwelling time was 7 days (range, 1-39 days) and EVD-associated infection occurred 6 days after insertion (range, 1-17 days). In 23% of patients, meningitis occurred 1-10 days after EVD removal. Fever >38 °C was present in 79% of patients, but Glasgow Coma Scale (GCS) scores were reduced in only 29%, and headache, vomiting and/or neck stiffness were present in only 31%. The median cerebrospinal fluid (CSF) leukocyte count was higher at onset of EVD-associated infection than at EVD insertion (175 × 10(6)/l versus 46 × 10(6)/l, p = 0.021), but other CSF parameters did not differ significantly. The most commonly implicated organisms were coagulase-negative staphylococci (63%) and Propionibacterium acnes (15%). CONCLUSIONS: Fever and increased CSF leukocytes should raise the suspicion of EVD-associated infection, which may occur up to 10 days after removal of EVD.

Implication des biofilms dans la rhinosinusite chronique et l’évaluation des traitements avec un modèle in vitro

Introduction : La chronicité de la rhinosinusite, sa résistance aux antibiotiques, et ses exacerbations aiguës laissent croire que les biofilms sont impliqués dans la rhinosinusite chronique. Objectifs : Nous avons évalué la capacité des bactéries Pseudomonas aeruginosa, staphylocoques à coagulase négative et Staphylococcus aureus à former des biofilms par un essai in vitro, et si cette capacité de formation a un lien avec l’évolution de la maladie. Nous avons évalué in vitro l’effet de la moxifloxacine, un antibiotique utilisé dans le traitement de la rhinosinusite chronique sur des biofilms matures de Staphylococcus aureus. Méthodes : Trent et une souches bactériennes ont été isolées de 19 patients atteints de rhinosinusite chronique et qui ont subit au moins une chirurgie endoscopique des sinus. L’évolution de la maladie a été notée comme "bonne" ou "mauvaise" selon l’évaluation du clinicien. La production de biofilm a été évaluée grâce à la coloration au crystal violet. Nous avons évalué la viabilité du biofilm après traitement avec la moxifloxacine. Ces résultats ont été confirmés en microscopie confocale à balayage laser et par la coloration au LIVE/DEAD BacLight. Résultat et Conclusion : Vingt deux des 31 souches ont produit un biofilm. La production d’un biofilm plus importante chez Pseudomonas aeruginosa et Staphylococcus aureus était associée à une mauvaise évolution. Ceci suggère un rôle du biofilm dans la pathogenèse de la rhinosinusite chronique. Le traitement avec la moxifloxacine, à une concentration de 1000X la concentration minimale inhibitrice réduit le nombre des bactéries viables de 2 à 2.5 log. Ces concentrations (100 µg/ml - 200 µg/ml) sont faciles à atteindre dans des solutions topiques. Les résultats de notre étude suggèrent que l’utilisation de concentrations supérieure à la concentration minimale inhibitrice sous forme topique peut ouvrir des voies de recherche sur de nouveaux traitements qui peuvent être bénéfiques pour les patients atteints de forme sévère de rhinosinusite chronique surtout après une chirurgie endoscopique des sinus.

Facteurs de risque modifiables associés à l’incidence, l’élimination et la prévalence d’infections intra-mammaires chez la vache laitière en lactation

La mammite subclinique est un problème de santé fréquent et coûteux. Les infections intra-mammaires (IIM) sont souvent détectées à l’aide de mesures du comptage des cellules somatiques (CCS). La culture bactériologique du lait est cependant requise afin d’identifier le pathogène en cause. À cause de cette difficulté, pratiquement toutes les recherches sur la mammite subclinique ont été centrées sur la prévalence d’IIM et les facteurs de risque pour l’incidence ou l’élimination des IIM sont peu connus. L’objectif principal de cette thèse était d’identifier les facteurs de risque modifiables associés à l’incidence, l’élimination et la prévalence d’IIM d’importance dans les troupeaux laitiers Canadiens. En premier lieu, une revue systématique de la littérature sur les associations entre pratiques utilisées à la ferme et CCS a été réalisée. Les pratiques de gestion constamment associées au CCS ont été identifiées et différentiées de celles faisant l’objet de rapports anecdotiques. Par la suite, un questionnaire bilingue a été développé, validé, et utilisé afin de mesurer les pratiques de gestion d’un échantillon de 90 troupeaux laitiers canadiens. Afin de valider l’outil, des mesures de répétabilité et de validité des items composant le questionnaire ont été analysées et une évaluation de l’équivalence des versions anglaise et française a été réalisée. Ces analyses ont permis d’identifier des items problématiques qui ont du être recatégorisés, lorsque possible, ou exclus des analyses subséquentes pour assurer une certaine qualité des données. La plupart des troupeaux étudiés utilisaient déjà la désinfection post-traite des trayons et le traitement universel des vaches au tarissement, mais beaucoup des pratiques recommandées n’étaient que peu utilisées. Ensuite, les facteurs de risque modifiables associés à l’incidence, à l’élimination et à la prévalence d’IIM à Staphylococcus aureus ont été investigués de manière longitudinale sur les 90 troupeaux sélectionnés. L’incidence d’IIM semblait être un déterminant plus important de la prévalence d’IIM du troupeau comparativement à l’élimination des IIM. Le port de gants durant la traite, la désinfection pré-traite des trayons, de même qu’une condition adéquate des bouts de trayons démontraient des associations désirables avec les différentes mesures d’IIM. Ces résultats viennent souligner l’importance des procédures de traite pour l’obtention d’une réduction à long-terme de la prévalence d’IIM. Finalement, les facteurs de risque modifiables associés à l’incidence, à l’élimination et à la prévalence d’IIM à staphylocoques coagulase-négatif (SCN) ont été étudiés de manière similaire. Cependant, afin de prendre en considération les limitations de la culture bactériologique du lait pour l’identification des IIM causées par ce groupe de pathogènes, une approche semi-Bayesienne à l’aide de modèles de variable à classe latente a été utilisée. Les estimés non-ajusté de l’incidence, de l’élimination, de la prévalence et des associations avec les expositions apparaissaient tous considérablement biaisés par les imperfections de la procédure diagnostique. Ce biais était en général vers la valeur nulle. Encore une fois, l’incidence d’IIM était le principal déterminant de la prévalence d’IIM des troupeaux. Les litières de sable et de produits du bois, de même que l’accès au pâturage étaient associés à une incidence et une prévalence plus basse de SCN.

Characterization of resistance in vitro to different antimicrobial in strains of Staphylococcus spp. in a hospital of the city of Valledupar between January and July 2009

The Staphylococcus spp. they can cause a wide range of infections systemic and located in community and hospital patients. Its high pathogenicity and growing resistance to multiple antimicrobials including methicillin, causes high morbiditymortality rates, causing a high epidemiological impact. Objective: to determine the phenotypic profile of resistance to different antimicrobials in strains of the genus Staphylococcus spp. Materials and methods: collected 75 strains and determined them susceptibility to different antibiotics by the Kirby-Bauer method. The production of betalactamasecheck using the nitrocefin test. (Resistance to Methicillin in S. aureus was conductedusing Mueller Hinton with 4% NaCl and oxacillin 6 μg/mL). Inducible clindamycin resistance tamizo by D-Test test. Results: they were isolated by 38% of staphylococcus coagulase negative (SNA) and 62% of S. aureus. 53% were penicillin resistant staphylococci: S. aureus with 58% and 42% SNA. 47% of the strains showed resistance to methicillin: S. aureus with 61% and SNA with 39%. A strain of S. aureus showed inducible resistance to clindamycin (1.33%). Coagulase negative staphylococci were isolated mostly from blood samples (31%), blood (29%), tip of catheter (5%) and came mostly from neonatal ICU (25%), medical (21%) and surgery (16%).Conclusions: S. aureus and SNA were isolated with greater frequency in blood and wounds from surgery and neonatal ICU. The predominant resistance phenotypes were penicillin and oxacillin.

Avaliação da relação entre contagens de células somáticas e os agentes mais prevalentes de mastite em explorações leiteiras da região de entre Douro e Vouga

Quando um microrganismo patogénico invade a glândula mamária, através do canal do teto, pode ocorrer infecção intramamária, desencadeando uma resposta inflamatória – a mastite. Esta possui diversas etiologias, sendo normalmente de origem bacteriana. Na resposta inflamatória, actuam as células somáticas presentes no leite. O presente estudo teve como principal objectivo avaliar a relação entre as contagens de células somáticas e os agentes causadores de mastite em amostras de leite. Foram utilizados dados referentes aos resultados de análises de leite para diagnóstico de mastite realizadas em amostras de explorações de Entre Douro e Vouga. Os resultados consistem em identificação dos agentes e respectivo antibiograma, CCS, sendo ainda registado o objectivo da análise (Secagem ou Tratamento). Determinaram-se as prevalências dos agentes, avaliando de seguida a relação entre as seguintes variáveis: agentes e CCS; CCS e objectivo da análise; e entre agentes e objectivo da análise. Concluiu-se que os Staphylococcus coagulase-negativa são os mais prevalentes, 14,5%, seguindo, Streptococcus uberis, 7,6%; Escherichia coli, 6,3%; Lactococcus garviae, 5,8% e Staphylococcus aureus, 4,1%. Concluiu-se ainda, a existência de diferenças estatisticamente significativas nas análises realizadas, confirmando a relação entre as demais variáveis.

Molecular identification of Staphylococcus xylosus MAK2, a new α-l-rhamnosidase producer

A bacterial strain, MAK-2, was isolated as a producer of α-l-rhamnosidase from a soil sample of Dehradoon, India. The strain was identified based on morphology, physiological tests and 16S rDNA analysis. The phylogenetic analysis based on the 16S rDNA sequence, identified the isolate as Staphylococcus xylosus, a nonpathogenic member of CNS (coagulase-negative staphylococci) family. The strain was capable of producing α-l-rhamnosidase by hydrolysing flavonoids thus confirming potential application in the citrus-processing industry.

Avaliação do potencial de formigas (Hymenoptera: formicidae) como vetores mecânicos de bactérias do gêneroSstaphylococcus no ambiente hospitalar.

In a hospital environment, these bacteria can be spread by insects such as ants, which are characterized by high adaptability to the urban environment. Staphylococcus is a leading cause of hospital infection. In Europe, Latin America, USA and Canada, the group of coagulase negative staphylococci (CoNS) is the second leading cause of these infections, according to SENTRY (antimicrobial surveillance program- EUA). In this study, we investigated the potential of ants (Hymenoptera: Formicidae) as vehicle mechanics of Staphylococcus bacteria in a public hospital, in Natal-RN. The ants were collected, day and night, from June 2007 to may 2008, in the following sectors: hospitals, laundry, kitchen, blood bank. The ants were identified according to the identification key of Bolton, 1997. For the analysis of staphylococci, the ants were incubated in broth Tryptic Soy Broth (TSB) for 24 hours at 35 º C and then incubated on Mannitol Salt Agar. The typical colonies of staphylococci incubated for 24 hours at 35 ° C in Tryptic Soy Agar for the characterization tests (Gram stain, catalase, susceptibility to bacitracin and free coagulase). The identification of CoNS was performed through biochemical tests: susceptibility to novobiocin, growth under anaerobic conditions, presence of urease, the ornithine decarboxylation and acid production from the sugars mannose, maltose, trehalose, mannitol and xylose. The antimicrobial susceptibility examined by disk-diffusion technique. The technique of Polymerase Chain Reaction was used to confirm the presence of mecA gene and the ability to produce biofilm was verified by testing in vitro using polystyrene inert surface, in samples of resistant staphylococci. Among 440 ants, 85 (19.1%) were carrying coagulase-negative staphylococci (CoNS) of the species Staphylococcus saprophyticus (17), Staphylococcus epidermidis (15), Staphylococcus xylosus (13), Staphylococcus hominis hominis (10), Staphylococcus lugdunensis (10), Staphylococcus warneri (6), Staphylococcus cohnii urealyticum (5), Staphylococcus haemolyticus (3), Staphylococcus simulans (3), Staphylococcus cohnii cohnii (2), and Staphylococcus capitis (1). No Staphylococcus aureus was found. Among the isolates, 30.58% showed resistance to erythromycin. Two samples of CoNS (2.35%), obtained from the ant Tapinoma melanocephalum collected in the post-surgical female ward, S. Hominis hominis and S. lugdunensis harbored the mecA gene and were resistant to multiple antibiotics, and the specie S. hominis hominis even showed to be a biofilm producer. This study proves that ants act as carriers of multidrug-resistant coagulase-negative Staphylococci and biofilm producers and points to the risk of the spreading of pathogenic microorganisms by this insect in the hospital environment

Ocorrência de Staphylococcus sp. em água utilizada em propriedades leiteiras do Estado de São Paulo

Com o objetivo de verificar o papel da água utilizada durante a produção do leite como via de transmissão de Staphylococcus sp., fez-se a contagem de Staphylococcus coagulase negativa e Staphylococcus aureus nas amostras de água das fontes, dos reservatórios e dos estábulos de 30 propriedades leiteiras situadas na região Nordeste do Estado de São Paulo. As maiores ocorrências de isolamentos (10,0 e 16,6%) e os maiores valores médios (4,3×10(4) e 2,5×10(4)) de contagens desses microrganismos foram encontrados nas amostras de água dos estábulos utilizada na obtenção de leite. Estes resultados são importantes pois evidenciam a possibilidade de contaminação do leite ou dos animais por cepas patogênicas.

The role of virulence factors in the outcome of staphylococcal peritonitis in CAPD patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Peritonitis in recent years: clinical findings and predictors of treatment response of 170 episodes at a single Brazilian center

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparison between qualitative and semiquantitative catheter-tip cultures: laboratory diagnosis of catheter-related infection in newborns

Este estudo prospectivo avaliou os métodos semiquantitativo e qualitativo de cultura de cateter para o diagnóstico de infecção relacionada a cateter (IRC) em recém-nascidos (RN). Foram incluídas pontas de cateteres provenientes de recém-nascidos internados na Unidade Neonatal do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP. Foram utilizadas as técnicas semiquantitativa e qualitativa de cultura de cateter. Para o diagnóstico de IRC, os microrganismos isolados das culturas de cateteres e de hemoculturas periféricas foram identificados e submetidos ao teste de sensibilidade a antimicrobianos. O padrão ouro correspondeu ao diagnóstico de certeza de IRC, com o isolamento do mesmo microrganismo (espécie e perfil de sensibilidade a antimicrobianos) isolado em hemocultura periférica. Foram estudados 85 cateteres provenientes de 63 RN. A cultura semiquantitativa, embora tenha apresentado menor sensibilidade (90%), apresentou uma maior especificidade (71%) em comparação à sensibilidade de 100% e especificidade de 60% encontradas na cultura qualitativa. Através da identificação dos microrganismos obtidos nas culturas de cateteres, observou-se uma predominância de espécies de Estafilococos coagulase-negativa (ECN). A espécie Staphylococcus epidermidis foi a prevalente (77,5%) nos cateteres com culturas semiquantitativas positivas. Dos 11 episódios de IRC diagnosticados, 8 (72,7%) foram associados a espécies de ECN, dos quais 6 eram da espécie S. epidermidis. Também foram detectados dois casos de IRC por S. aureus e um caso por Candida parapsilosis. O método de cultura semiquantitativo cateter apresentou vantagens para o diagnóstico de IRC em RN quando comparado com o método qualitativo tradicional.