Microbiological diagnosis of intramedullary nailing infection: comparison of bacterial growth between tissue sampling and sonication fluid cultures.

BACKGROUND: Intramedullary nailing (IMN) has been frequently indicated to treat long bone open and closed fractures, but IMN infection (IMNI) may have devastating consequences. Sonication has been regarded as an important add-on for microbial identification on a variety of orthopaedic implant-associated infections, but its role in the IMNI is poorly studied. We aim at evaluating the accuracy obtained by conventional peri-implant tissue culture (TC) samples with sonication fluid cultures (SCs) of IMNI. METHODS: Longitudinal prospective cohort study ongoing since June 2014, which included patients with indication for IMN removal due to any reason. Clinical diagnosis of INMI was defined according to publication addressing fracture-related infections. Minimal of two samples from TC were cultured. SCs followed the protocol previously published. Statistical analysis was performed using McNemar's test for related proportions. RESULTS: We included 54 patients submitted to IMN retrieval, of whom 47 presenting clinical signs of IMNI. Sensitivity for detecting microorganisms using TC and SC was 89.4% (42/47) and 97.6% (40/41), and specificity was 71.4% (5/7) for both TC and SC (p = 1.00). Positive and negative predictive values for TC and SC were 95.5% (42/44), 95.2% (40/42), 50% (5/10), and 83.3% (5/6), respectively. The most frequent organisms isolated in both TC and SC were Staphylococcus aureus, S. epidermidis, and Enterococcus sp. Polymicrobial infection was diagnosed in 14.8% (8/54) and 25% (12/48) by TC and SC, respectively (p = 0.19). CONCLUSION: Sonication fluid and tissue samples presented similar accuracy on the diagnosis of IMNI, but SC was advantageous of detecting polymicrobial infection.

In vitro antibacterial activity of bioactive glass S53P4 on multiresistant pathogens causing osteomyelitis and prosthetic joint infection.

BACKGROUND: Conventional local treatment for medullary osteomyelitis (OM) includes insertion of antibiotic-loaded polymethylmethacrylate (PMMA) cement. Nevertheless, PMMA may delivery irregular concentration of antibiotic to surrounding tissue. We aimed to compare the in vitro antibacterial activity of Bioactive Glass (BAG) S53P4, which is a compound showing local antibacterial activity, to that of antibiotic-loaded PMMA against multidrug resistant bacteria from OM isolates. METHODS: We studied convenience samples of multidrug resistant (MDR) microorganisms obtained from patients presenting OM and prosthetic joint infection (PJI). Mixtures containing tryptic soy broth (TSB) and inert glass beads (2 mm), BAG-S53P4 granules (0.5-0.8 mm and < 45 mm) and Gentamicin or Vancomycin-loaded PMMA beads were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MR-CoNS), Pseudomonas aeruginosa or Klebsiella pneumoniae isolates. Glass beads (2.0 mm) were used as a control. Antibacterial activity was evaluated by means of time-kill curve, through seeding the strains on blood agar plates, and subsequently performing colony counts after 24, 48, 72, 96, 120 and 168 h of incubation. Differences between groups were evaluated by means of two-way analysis of variance (ANOVA) and Bonferroni's t test. RESULTS: Inhibition of bacterial growth started soon after 48 h of incubation, reached zero CFU/ml between 120 and 168 h of incubation for both antibiotic-loaded PMMA and BAG S53P4 groups, in comparison with inert glass (p < 0.05). No difference regarding time-kill curves between antibiotic-loaded PMMA and BAG S53P4 was observed. CONCLUSIONS: BAG S53P4 presented antibacterial properties as much as antibiotic-loaded PMMA for MDR bacteria producing OM and PJI.

Microbial diagnosis of infection and colonization of cardiac implantable electronic devices by use of sonication.

OBJECTIVES: The clinical utility of sonication as an adjunctive diagnostic tool for the microbial diagnosis of cardiac implantable device-associated infections (CIDAIs) was investigated. METHODS: The implants of 83 subjects were investigated, 15 with a CIDAI and 68 without a clinical infection. Clinical data were analyzed prospectively and sonication fluid cultures (83 patients, 100%) and traditional cultures (31 patients, 37.4%) were performed RESULTS: Generator pocket infection and device-related endocarditis were found in 13 (86.7%) and four (26.7%) subjects, respectively. The mean numbers of previous technical complications and infections were higher in the infected patients compared to the non-infected patients (8 vs. 1, p<0.001; 2 vs. 0, p<0.031, respectively). The sensitivity and specificity for detecting CIDAI was 73.3% (11/15) and 48.5% (33/68) for sonication fluid culture, and 26.7% (4/15) and 100% (16/16) for traditional culture (p<0.001), respectively. A higher number of organisms were identified by sonication fluid than by tissue culture (58 vs. 4 specimens; p<0.001). The most frequent organisms cultured were Gram-positive cocci (66.1%), mainly coagulase-negative staphylococci (35.5%). Thirty-five (51.5%) non-infected subjects were considered colonized due to the positive identification of organisms exclusively through sonication fluid culture. CONCLUSIONS: Sonication fluid culture from the removed cardiac implants has the potential to improve the microbiological diagnosis of CIDAIs.

Comparação entre dois meios de coleta e transporte para estudo da microbiota conjuntival de indivíduos normais / Comparison of two transportation media for study of normal individual conjunctival microbiota

OBJETIVO: Comparar o perfil microbiológico da microbiota de pessoas sadias, obtidas do esfregaço conjuntival, utilizando zaragatoa seca transportada no meio de Stuart e zaragatoa úmida transportada no tubo de ensaio vedado com algodão. MÉTODOS: Trata-se de estudo prospectivo, com amostras selecionadas aleatoriamente, realizado no Departamento de Oftalmologia e Patologia da Santa Casa de Misericórdia de São Paulo, no mês de agosto de 2006. Foram estudados 80 olhos normais de 40 indivíduos. No olho direito de cada paciente, foi realizada a coleta de material com a zaragatoa seca, armazenando-a no meio de transporte de Stuart, no qual todo o material microbiológico obtido fica imerso no meio e o tubo hermeticamente fechado. No olho esquerdo, o material conjuntival foi colhido com a extremidade de algodão da zaragatoa umedecida em solução salina a 0,9 por cento, e armazenando-a no tubo de ensaio seco e estéril vedado com algodão. As amostras foram analisadas no prazo máximo de 2 horas após a coleta do material. RESULTADOS: Das 40 amostras coletadas com a zaragatoa úmida transportadas em tubo seco, foram identificadas bactérias em 10 (25 por cento). Das 40 amostras coletadas com zaragatoa seca transportada em meio de Stuart, foram identificadas bactérias em 12 (30 por cento). CONCLUSÃO: Os resultados do perfil microbiológico da microbiota normal conjuntival utilizando o meio de transporte da zaragatoa seca em meio de Stuart mostraram-se estatisticamente semelhantes (p= 0,85) ao comparar com o meio utilizando a zaragatoa úmida em tubo seco para semeaduras realizadas em até 2 horas após a coleta de material conjuntival.

PURPOSE: To compare the microbiological profile of normal microbiota of healthy people obtained from conjunctival smear using dry swab in Stuart's transport medium and wet swab transported in test tube sealed with cotton. METHODS: A prospective study with random samples, performed at the Departments of Ophthalmology and Pathology of Santa Casa Misericórdia de São Paulo, in August of 2006. Eighty normal eyes of 40 healthy individuals were analyzed. Samples were collected in the right eye with a dry swab and stored in Stuart's medium, where all microbiological material is kept immersed in the medium and the tube is hermetically sealed. In the left eye, the conjunctival material was collected using a swab embedded in saline solution 0.9 percent, and stored in dry and sterile test tubes sealed with cotton. The samples were analyzed within 2 hours at most after collection. RESULTS: Out of 40 samples collected with wet swab and transported in dry tube, bacteria were observed in 10 (25 percent), whereas of 40 samples collected with dry swab and transported in Stuart's medium, 12 (30 percent) had bacteria. CONCLUSION: The results of the microbiological profile of normal conjunctival microbiota using dry swab in Stuart's medium were statistically similar (p=0.85) to those obtained in wet swab in dry tube for spreading performed within 2 hours after collection of conjunctival specimen.

[Comparison of two transportation media for study of normal individual conjunctival microbiota]. / Comparação entre dois meios de coleta e transporte para estudo da microbiota conjuntival de indivíduos normais.

PURPOSE: To compare the microbiological profile of normal microbiota of healthy people obtained from conjunctival smear using dry swab in Stuart's transport medium and wet swab transported in test tube sealed with cotton. METHODS: A prospective study with random samples, performed at the Departments of Ophthalmology and Pathology of Santa Casa Misericórdia de São Paulo, in August of 2006. Eighty normal eyes of 40 healthy individuals were analyzed. Samples were collected in the right eye with a dry swab and stored in Stuart's medium, where all microbiological material is kept immersed in the medium and the tube is hermetically sealed. In the left eye, the conjunctival material was collected using a swab embedded in saline solution 0.9%, and stored in dry and sterile test tubes sealed with cotton. The samples were analyzed within 2 hours at most after collection. RESULTS: Out of 40 samples collected with wet swab and transported in dry tube, bacteria were observed in 10 (25%), whereas of 40 samples collected with dry swab and transported in Stuart's medium, 12 (30%) had bacteria. CONCLUSION: The results of the microbiological profile of normal conjunctival microbiota using dry swab in Stuart's medium were statistically similar (p=0.85) to those obtained in wet swab in dry tube for spreading performed within 2 hours after collection of conjunctival specimen.

[Risk of contamination of trypan blue dye after first use]. / Risco de contaminação do corante azul de tripano após primeira utilização.

PURPOSE: To determine the potential risk of contamination of a trypan blue bottle (TB) after first use and after being stored under different temperature and humidity conditions, as well as to identify possible contamination factors, most frequently involved microorganisms and simultaneously evaluate bacteriostatic and bactericide properties of the dye. METHODS: An experimental and prospective study was carried out, in which 30 TB bottles were divided into 3 groups (A: control, B: refrigerator storage and C: cabinet storage). The dye was suctioned and cultivated in agar blood plates and Sabouraud agar tube. In group A, TB was cultivated immediately after the opening of the bottles (temperature zero - T0), in groups B and C cultivation occurred in T0, T1 (1 day), T2 (2 days), T7 (7 days) and T10 (10 days) after the opening of the bottles. On the 10th day, groups B and C bottles were also submitted to scraping of their inner walls after opening. Concurrently, the inhibitory action measurement test was conducted on the TB dye for the study of bacteriostatic and bactericidal activity. RESULTS: Cultivation procedures conducted in T0 presented no contamination. Among T1 and T10, added to the scraping there was only one contaminated bottle stored in the refrigerator. The encountered microorganism was Aspergillus niger. It has been proven that the dye does not show bactericide and bacteriostatic properties against the bacteria which were tested. CONCLUSIONS: Under this study's conditions there was no contamination of the bottles stored in cabinets and 1 bottle (10%) stored in the refrigerator showed contamination after opening and initial use. The source of contamination may possibly be the outer part of the product. TB does not show bactericidal and bacteriostatic properties against the tested bacteria and in the applied concentration.

Risco de contaminacão do corante azul de tripano após primeira utilizacão / Risk of contamination of trypan blue dye after first use

OBJETIVOS: Determinar o potencial risco de contaminacão do frasco de azul de tripano (AT) depois de utilizado pela primeira vez e estocado em diferentes condicões de temperatura e umidade, assim como identificar os possíveis fatores de contaminacão, microrganismos mais freqüentemente envolvidos e simultaneamente avaliar as propriedades bacteriostáticas e bactericidas do corante. MÉTODOS: Realizado estudo experimental, prospectivo, em que 30 frascos de AT foram divididos em três grupos (A: controle, B: armazenamento em geladeira e C: armazenamento em armário). O corante era aspirado e semeado em placas de ágar sangue e tubo de ágar Sabouraud. No grupo A o AT foi semeado apenas logo após a abertura dos frascos (tempo zero - T0), nos grupos B e C ocorreu semeadura nos T0, T1 (1 dia), T2 (2 dias), T7 (7 dias) e T10 (10 dias) após abertura dos frascos. No 10º dia os frascos dos grupos B e C também foram submetidos a um raspado do lado interno do frasco após abertura. Concomitantemente foi realizado teste de acão inibitória do corante AT para estudo da atividade bacteriostática e bactericida. RESULTADOS: As semeaduras realizadas no T0 não apresentaram contaminacão. Entre os T1 e T10 mais o raspado houve apenas 1 frasco contaminado armazenado em geladeira. O microrganismo encontrado foi o Aspergillus niger. Foi comprovado que o corante não apresenta acão bactericida e bacteriostática para as bactérias testadas. CONCLUSÕES: Nas condicões do estudo não houve contaminacão dos frascos armazenados em armário e 1 frasco (10 por cento) armazenado em geladeira apresentou contaminacão após abertura e uso inicial. A fonte de contaminacão talvez seja o lado externo do produto. O AT não apresenta propriedades bactericidas e bacteriostáticas para as bactérias testadas e na concentracão utilizada.

Estudo comparativo in vitro entre a associaçäo de valerato de betametasona, sulfato de gentamicina, tolnaftato e clioquinol versus outros compostos nas cepas bacterianas e fúngicas mais freqüêntes nos meios comunitário e hospitalar / In vitrto comparative study between the association of betamethasone valerato, gentamicin sulfate, tolnaftate and clioquinol versus other medications on frequent bacterials and fungicals samples from communitary and hospitalar environment

A freqüência das infecçöes associadas fúngico-bacterianas cutâneas é um achado muito freqüênte na prática clínica diária. Devido a isso, o encontro de um produto eficiente para resolver essas dermatoses, economicamente viável e com uma comodidade de aplicaçäo é um desafio para os médicos no mundo inteiro. No corrente estudo, verificamos que a eficácia "in vitro" da associaçäo de valerato de betametasona, sulfato de gentamicina, tolnaftato e clioquinol em 20 cepas de Candida spp., Trichophytun spp., Streptococcus pyogenes, Staphylococcus aureus, Acinetobacter sp.,Escherichia coli, Pseudomonas aeruginosa e Pseudomonas aeruginosa resistente variou de 95 a 100 porcento, sendo maior e mais abrangente do que outros produtos antimicrobianos usados freqüêntemente em nosso mercado. Podemos considerar essa associaçäo uma alternativa eficaz no tratamento de infecçöes cutâneas com associaçäo de bactérias e fungos.(au)