In vivo monitoring of Lactiplantibacillus plantarum in the nasal and vaginal mucosa using infrared fluorescence.

Lactic acid bacteria (LAB) of the genus Lactiplantibacillus have been explored as potential mucosal vaccine vectors due to their ability to elicit an immune response against expressed foreign antigens and to their safety. However, tools for monitoring LAB distribution and persistence at the mucosal surfaces are needed. Here, we characterize Lactiplantibacillus plantarum bacteria expressing the infrared fluorescent protein IRFP713 for exploring their in vivo distribution in the mucosa and potential use as a mucosal vaccine vector. This bacterial species is commonly used as a vaginal probiotic and was recently found to have a niche in the human nose. Three different fluorescent L. plantarum strains were obtained using the nisin-inducible pNZRK-IRFP713 plasmid which contains the nisRK genes, showing stable and constitutive expression of IRFP713 in vitro. One of these strains was further monitored in BALB/c mice using near-infrared fluorescence, indicating successful colonization of the nasal and vaginal mucosae for up to 72 h. This study thus provides a tool for the in vivo spatiotemporal monitoring of lactiplantibacilli, allowing non-invasive bacterial detection in these mucosal sites. KEY POINTS: • Stable and constitutive expression of the IRFP713 protein was obtained in different L. plantarum strains. • IRFP713+ L. plantarum 3.12.1 was monitored in vivo using near-infrared fluorescence. • Residence times observed after intranasal and vaginal inoculation were 24-72 h.

Large Increase in Azithromycin-Resistant Neisseria gonorrhoeae in Northern Spain.

The aim of this study was to characterize the evolution of gonorrhea in the general population by correlating epidemiological, genotypic, and antimicrobial resistance data of Neisseria gonorrhoeae isolates collected in northern Spain from 2014 to 2018. One hundred ninety-four strains underwent antimicrobial susceptibility testing and were genetically analyzed by N. gonorrhoeae multiantigen sequence typing. Increasing cases of gonococcal infections have been observed after 2015. Most occurred in male with urethritis. Sequence type (ST)-9972 and ST-1576, the predominant genotypes identified, have not been previously described as epidemic clones. Of great concern was the significant increase in azithromycin-resistant N. gonorrhoeae. More than 30% of these isolates were obtained from men who have sex with men (MSM). ST-12302 was the most prevalent clone among the azithromycin-resistant strains, and was also resistant to penicillin, ciprofloxacin, and tetracycline. This multidrug-resistant clone was exclusively isolated from MSM during 2018. The incidence rates of gonorrhea and azithromycin-resistant N. gonorrhoeae have significantly increased due to the emergence of new clones. ST-12302 has recently been recognized as an epidemic clone; therefore, its surveillance could be the key in controlling further dissemination of azithromycin resistance. These data highlight the need to perform local studies to update treatment guidelines and reinforce preventive measures against gonorrhea.

In Vitro Anti-Biofilm and Antibacterial Properties of Streptococcus downii sp. nov.

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

Detection and quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Streptococcus oralis in blood samples with different microbiological identification methods: An in vitro study.

BACKGROUND: Culture-based methods (culture broth bottles or lysis methods) have been the standard for detecting bacteremia. More recently, quantitative polymerase chain reaction (qPCR) was proposed as a more sensitive and specific test although none of them has been validated for the identification of periodontal pathogens (fastidious growing bacteria) in blood samples. OBJECTIVE: To compare the ability to detect and quantify Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Streptococcus oralis (alone or in combination) in blood samples with three culture techniques [direct anaerobic culturing (DAC), haemo-culture (BACTEC), and lysis-centrifugation (LC)] and a non-culture dependent approach (qPCR) in an in vitro study. MATERIAL AND METHODS: Blood samples from 12 periodontally healthy volunteers were contaminated with three concentrations [104,102 and 101 colony forming units (CFU)/mL] of A. actinomycetemcomitans, P. gingivalis and S. oralis, alone or in combination. Samples were analysed by DAC, BACTEC, LC and qPCR. Sensitivity, specificity, predictive values, kappa index and Lins correlation coefficients were calculated. RESULTS: DAC, LC and qPCR were able to detect the three target species at all concentrations. An excellent concordance (correlation coefficient r: 0.92-1) was observed between DAC and the reference standard (sensitivity raging 93.33-100% and specificity 88.89-100%) values. BACTEC was not able to identify P. gingivalis in any of the performed experiments. qPCR provided false negative results for S.oralis. CONCLUSIONS: DAC showed the best results for the proper identification and quantification of A. actinomycetemcomitans, P. gingivalis and S. oralis, alone or in combination, in blood samples.

Dataset for analysing the relationships among economic growth, fossil fuel and non-fossil fuel consumption.

The data presented in this article are related to the research article entitled 'Economic Growth, Fossil Fuel and Non-Fossil Consumption: A Pooled Mean Group Analysis using Proxies for Capital' (J. Asafu-Adjaye, D. Byrne, M. Alvarez, 2016) [1]. This article describes data modified from three publicly available data sources: the World Bank׳s World Development Indicators (http://databank.worldbank.org/data/reports.aspx?source=world-development-indicators), the U.S. Energy Information Administration׳s International Energy Statistics (http://www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm?tid=44&pid=44&aid=2) and the Barro-Lee Educational Attainment Dataset (http://www.barrolee.com). These data can be used to examine the relationships between economic growth and different forms of energy consumption. The dataset is made publicly available to promote further analyses.

Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) clones with high-level mupirocin resistance.

A high proportion of methicillin-resistant Staphylococcus aureus isolates recovered in one year period showed high-level mupirocin-resistance (HLMUPR-MRSA) in our environment (27.2%). HLMUPR-MRSA isolates were mainly collected from skin and soft tissue samples, and diabetes was the main related comorbidity condition. These isolates were more frequently found in vascular surgery. HLMUPR-MRSA was more resistant to aminoglycosides than mupirocin-susceptible MRSA, linked to the presence of bifunctional and/or nucleotidyltransferase enzymes with/without macrolide resistance associated with the msr(A) gene. Most of HLMUPR-MRSA isolates belonged to ST125/t067. Nine IS257-ileS2 amplification patterns (p3 was the most frequent) were observed in HLMUPR-MRSA isolates, suggesting the presence of several mupirocin-resistance-carrying plasmids in our environment and promoting the emergence of mupirocin resistance. The presence of the same IS257-ileS2 amplification pattern p3 in 65% of HLMUPR-MRSA, all of them ST125/t067, suggests a clonal spread in our hospital and community environment which could explain the high prevalence of HLMUPR-MRSA during the study period. An outbreak situation or an increase in mupirocin consumption was not observed.

Comparison of the detection of periodontal pathogens in bacteraemia after tooth brushing by culture and molecular techniques

BACKGROUND: The prevalence and amounts of periodontal pathogens detected in bacteraemia samples after tooth brushing-induced by means of four diagnostic technique, three based on culture and one in a molecular-based technique, have been compared in this study. MATERIAL AND METHODS: Blood samples were collected from thirty-six subjects with different periodontal status (17 were healthy, 10 with gingivitis and 9 with periodontitis) at baseline and 2 minutes after tooth brushing. Each sample was analyzed by three culture-based methods [direct anaerobic culturing (DAC), hemo-culture (BACTEC), and lysis-centrifugation (LC)] and one molecular-based technique [quantitative polymerase chain reaction (qPCR)]. With culture any bacterial isolate was detected and quantified, while with qPCR only Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were detected and quantified. Descriptive analyses, ANOVA and Chi-squared tests, were performed. RESULTS: Neither BACTEC nor qPCR detected any type of bacteria in the blood samples. Only LC (2.7%) and DAC (8.3%) detected bacteraemia, although not in the same patients. Fusobacterium nucleatum was the most frequently detected bacterial species. CONCLUSIONS: The disparity in the results when the same samples were analyzed with four different microbiological detection methods highlights the need for a proper validation of the methodology to detect periodontal pathogens in bacteraemia samples, mainly when the presence of periodontal pathogens in blood samples after tooth brushing was very seldom

Antimicrobial resistance, virulence factors and genetic lineages of hospital-onset methicillin-resistant Staphylococcus aureus isolates detected in a hospital in Zaragoza / Resistencia a antibióticos, factores de virulencia y líneas clonales de Staphylococcus aureus resistente a la meticilina de origen hospitalario en un hospital de Zaragoza

INTRODUCTION: MRSA population dynamics is undergoing significant changes, and for this reason it is important to know which clones are circulating in our nosocomial environment. MATERIALS AND METHODS: A total of 118 MRSA isolates were collected from clinical samples from patients with previous hospital or healthcare contact (named as hospital-onset MRSA (HO-MRSA)) during a one year period. Susceptibility testing was performed by disk diffusion and microdilution. The presence of resistance genes and virulence factors were tested by PCR. All isolates were typed by SCCmec, spa and agr typing. PFGE and MLST were applied to a selection of them. RESULTS: Eighty-three HO-MRSA isolates (70.3%) were resistant to any antibiotic included in the macrolide-lincosamide-streptogramin B group. Among these isolates, the M phenotype was the most frequent (73.5%). One hundred and seven of HO-MRSA isolates (90.7%) showed aminoglycoside resistance. The combination aac(6')-Ie-aph(2'')-Ia + ant(4')-Ia genes was the most frequent (22.4%). Tetracycline resistance rates in HO-MRSA isolates were low (3.4%), although a high level of mupirocin resistance was observed (25.4%). Most of the HO-MRSA isolates (approximately 90%) showed SCCmec type IVc and agr type II. Fifteen unrelated pulsotypes were identified. CC5 was the most prevalent (88.1%), followed by CC8 (5.9%), CC22 (2.5%), CC398 (2.5%) and CC1 (0.8%). CONCLUSION: CC5/ST125/t067 lineage was the most frequent. This lineage was related to aminoglycoside resistance, and to a lesser extent, with macrolide resistance. The presence of international clones as EMRSA-15 (CC22/ST22), European clones as CC5/ST228, community clones related to CC1 or CC8 and livestock associated clones, as CC398, were observed in a low percentage

INTRODUCCIÓN: Las dinámicas poblacionales de SARM están experimentando cambios significativos en los últimos tiempos. Por ello es importante conocer qué líneas clonales circulan en nuestro ambiente hospitalario. MATERIALES Y MÉTODOS: Durante un año, se seleccionaron 118 SARM de muestras clínicas de pacientes con contacto previo con el ambiente hospitalario (SARM de origen hospitalario [SARM-OH]). Las pruebas de sensibilidad se realizaron mediante difusión con discos y microdilución. La presencia de genes de resistencia y factores de virulencia fueron estudiados mediante PCR. Se estableció el tipo de SCCmec, spa y agr en todos los aislados, y en una selección se estudió su relación genética por PFGE y MLST. RESULTADOS: Ochenta y tres SARM-OH (70,3%) fueron resistentes a al menos un antibiótico del grupo de los macrólidos-lincosamidas-estreptograminas B. Entre estos, el fenotipo M fue el más frecuente (73,5%). Ciento siete aislamientos (90,7%) mostraron resistencia a aminoglucósidos. La combinación aac(6')-Ieaph( 2'')-Ia + ant(4')-Ia fue la más frecuente (22,4%). Las tasas de resistencia a tetraciclinas detectadas fueron bajas (3,4%). Se observó un 25,4% de resistencia de alto nivel a mupirocina. Aproximadamente un 90% de SARM-OH mostraron SCCmec tipo IVc y agr tipo II. Se identificaron 15 pulsotipos no relacionados. El CC5 fue el más prevalente (88,1%) seguido de CC8 (5,9%), CC22 (2,5%), CC398 (2,5%) y CC1 (0,8%). CONCLUSIÓN: La línea clonal CC5/ST125/t067 fue la más habitual. Esta línea se relacionó con resistencia a aminoglucósidos, y, en menor medida, con macrólidos. La presencia de clones internacionales como EMRSA-15 (CC22/ST22), clones europeos como CC5/ST228, clones comunitarios relacionados con CC1 o CC8 y clones asociados al ganado, como el CC398, se observaron en un bajo porcentaje

Post-tooth extraction bacteraemia: a randomized clinical trial on the efficacy of chlorhexidine prophylaxis.

OBJECTIVES: To investigate the development of post-extraction bacteraemia (PEB) after the prophylactic use of chlorhexidine (CHX). PATIENTS AND METHODS: A total of 201 patients who underwent a tooth extraction were randomly distributed into four groups: 52 received no prophylaxis (CONTROL), 50 did a mouthwash with 0.2% CHX before the tooth extraction (CHX-MW), 51 did a mouthwash with 0.2% CHX and a subgingival irrigation with 1% CHX (CHX-MW/SUB_IR) and 48 did a mouthwash with 0.2% CHX and a continuous supragingival irrigation with 1% CHX (CHX-MW/SUPRA_IR). Peripheral venous blood samples were collected at baseline, 30 seconds after performing the mouthwash and the subgingival or supragingival irrigation, and at 30 seconds and 15 minutes after completion of the tooth extraction. Blood samples were analysed applying conventional microbiological cultures under aerobic and anaerobic conditions performing bacterial identification of the isolates. RESULTS: The prevalences of PEB in the CONTROL, CHX-MW, CHX-MW/SUB_IR and CHX-MWSUPRA_IR groups were 52%, 50%, 55% and 50%, respectively, at 30 seconds and 23%, 4%, 10% and 27%, respectively, at 15 minutes. The prevalence of PEB at 15 minutes was significantly higher in the CONTROL group than in the CHX-MW group (23% versus 4%; p = 0.005). At the same time, no differences were found between CONTROL group and CHX-MW/SUB_IR or CHX-MW/SUPRA_IR groups. Streptococci (mostly viridans group streptococci) were the most frequently identified bacteria (69-79%). CONCLUSIONS: Performing a 0.2% CHX mouthwash significantly reduces the duration of PEB. Subgingival irrigation with 1% CHX didn't increase the efficacy of the mouthwash while supragingival irrigation even decreased this efficacy, probably due to the influence of these maneuvers on the onset of bacteraemia. CLINICAL RELEVANCE: These results confirm the suitability of performing a mouthwash with 0.2% CHX before tooth extractions in order to reduce the duration of PEB. This practice should perhaps be extended to all dental manipulations. TRIAL REGISTRATION: Clinicaltrials.gov NCT02150031.

Antimicrobial resistance, virulence factors and genetic lineages of hospital-onset methicillin-resistant Staphylococcus aureus isolates detected in a hospital in Zaragoza.

INTRODUCTION: MRSA population dynamics is undergoing significant changes, and for this reason it is important to know which clones are circulating in our nosocomial environment. MATERIALS AND METHODS: A total of 118 MRSA isolates were collected from clinical samples from patients with previous hospital or healthcare contact (named as hospital-onset MRSA (HO-MRSA)) during a one year period. Susceptibility testing was performed by disk diffusion and microdilution. The presence of resistance genes and virulence factors were tested by PCR. All isolates were typed by SCCmec, spa and agr typing. PFGE and MLST were applied to a selection of them. RESULTS: Eighty-three HO-MRSA isolates (70.3%) were resistant to any antibiotic included in the macrolide-lincosamide-streptogramin B group. Among these isolates, the M phenotype was the most frequent (73.5%). One hundred and seven of HO-MRSA isolates (90.7%) showed aminoglycoside resistance. The combination aac(6')-Ie-aph(2″)-Ia+ant(4')-Ia genes was the most frequent (22.4%). Tetracycline resistance rates in HO-MRSA isolates were low (3.4%), although a high level of mupirocin resistance was observed (25.4%). Most of the HO-MRSA isolates (approximately 90%) showed SCCmec type IVc and agr type II. Fifteen unrelated pulsotypes were identified. CC5 was the most prevalent (88.1%), followed by CC8 (5.9%), CC22 (2.5%), CC398 (2.5%) and CC1 (0.8%). CONCLUSION: CC5/ST125/t067 lineage was the most frequent. This lineage was related to aminoglycoside resistance, and to a lesser extent, with macrolide resistance. The presence of international clones as EMRSA-15 (CC22/ST22), European clones as CC5/ST228, community clones related to CC1 or CC8 and livestock associated clones, as CC398, were observed in a low percentage.

Phaeohyphomycosis caused by Cladophialophora bantiana / Feohifomicosis causada por Cladophialophora bantiana

Background. Cladophialophora bantiana is the most frequent cause of central nervous system phaeohyphomycosis. Aims. We report a case of phaeohyphomycosis by C. bantiana in a patient with underlying lung disease on steroid therapy. Methods. An 81-year-old male was admitted in August 2011 with a history of difficulty speaking and deflection of the oral commeasure to the left side with a brain abscess. Brain tissue was cultured on Sabouraud media and sequence analysis of the internal transcribed spacer region of the ribosomal DNA was done for identification purposes. Susceptibility testing to various antifungal agents was performed using the microdilution test. Results. Histopathological examination of the brain tissue ruled out malignancy and the presence of dematiaceous hyphae was observed. Culture showed the presence of a single black fungus, identified as C. bantiana. It was susceptible to all antifungals, except to caspofungin. The patient was treated with voriconazole plus liposomal amphotericin B. Cerebral cranial computed tomography [CCT] scans demonstrated persistence of the intraparenchymal abscess collection. Despite surgical and medical treatment with antifungal drugs, the patient died 5 months after the first diagnosis of the cerebral occupying lesion was made. Conclusions. Phaeohyphomycosis is an uncommon infection with severe limitations on the clinical clues that can help in early diagnosis. Fungal species identification is mandatory for epidemiological and therapeutic reasons. The MICs could be useful in selecting the appropriate antifungal agent. Avoiding the unnecessary exposure to soil or other media potentially contaminated with fungal spores should be recommended to any immunosuppressed patient (AU)

Antecedentes. Cladophialophora bantiana es la causa más frecuente de feohifomicosis del sistema nervioso central. Objetivos. Describimos un caso de feohifomicosis por C. bantiana en un paciente con una enfermedad pulmonar subyacente en tratamiento con corticosteroides. Métodos. En agosto de 2011, ingresa un hombre de 81 años de edad con antecedentes de dificultad para hablar y desviación de la comisura bucal a la izquierda por un absceso cerebral. Se cultivó el aspirado del absceso cerebral en medio de Sabouraud y para la identificación definitiva del hongo se secuenció la región espaciadora transcrita interna del ADN ribosomal. Las pruebas de sensibilidad a los diferentes antifúngicos se efectuaron mediante microdilución. Resultados. El examen histopatológico de las muestras descartó la presencia de un tumor maligno y confirmó la existencia de hifas. El cultivo reveló la presencia de un hongo dematiáceo identificado como Cladophialophora bantiana, sensible a todos los antifúngicos excepto a la caspofungina. El paciente fue tratado con voriconazol combinado con anfotericina B liposomal. La tomografía computarizada craneal mostró la persistencia del absceso intraparenquimatoso. A pesar del tratamiento con antifúngicos y del procedimiento quirúrgico, el paciente falleció 5 meses después de que se estableciera el diagnóstico inicial. Conclusiones. La feohifomicosis es una infección poco frecuente, con importantes limitaciones de los indicios clínicos que pueden contribuir a un diagnóstico precoz. Por razones tanto epidemiológicas como terapéuticas, es indispensable la identificación de la especie de hongo responsable. La determinación de la concentración inhibitoria mínima podría ser de utilidad en la selección del tratamiento antifúngico apropiado. Los pacientes inmunodeprimidos deben evitar la exposición al suelo u otros medios potencialmente contaminados por esporas de hongos (AU)

Usefulness of PCR-RFLP coa gene for clonal classification of methicillin-resistant Staphylococcus aureus isolates in tertiary hospitals.

One hundred and one methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates were classified into 10 genotypes based on their polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) coa pattern. PCR-RFLP coa patterns correlated with the clonal complex (CC) with the exception of CC5, which was related to 2 patterns (B and E). The PCR-RFLP coa gene technique provides a useful preliminary method to monitor variations in MRSA populations.

Phaeohyphomycosis caused by Cladophialophora bantiana.

BACKGROUND: Cladophialophora bantiana is the most frequent cause of central nervous system phaeohyphomycosis. AIMS: We report a case of phaeohyphomycosis by C. bantiana in a patient with underlying lung disease on steroid therapy. METHODS: An 81-year-old male was admitted in August 2011 with a history of difficulty speaking and deflection of the oral commeasure to the left side with a brain abscess. Brain tissue was cultured on Sabouraud media and sequence analysis of the internal transcribed spacer region of the ribosomal DNA was done for identification purposes. Susceptibility testing to various antifungal agents was performed using the microdilution test. RESULTS: Histopathological examination of the brain tissue ruled out malignancy and the presence of dematiaceous hyphae was observed. Culture showed the presence of a single black fungus, identified as C. bantiana. It was susceptible to all antifungals, except to caspofungin. The patient was treated with voriconazole plus liposomal amphotericin B. Cerebral cranial computed tomography [CCT] scans demonstrated persistence of the intraparenchymal abscess collection. Despite surgical and medical treatment with antifungal drugs, the patient died 5 months after the first diagnosis of the cerebral occupying lesion was made. CONCLUSIONS: Phaeohyphomycosis is an uncommon infection with severe limitations on the clinical clues that can help in early diagnosis. Fungal species identification is mandatory for epidemiological and therapeutic reasons. The MICs could be useful in selecting the appropriate antifungal agent. Avoiding the unnecessary exposure to soil or other media potentially contaminated with fungal spores should be recommended to any immunosuppressed patient.

Detection of transient bacteraemia following dental extractions by 16S rDNA pyrosequencing: a pilot study.

OBJECTIVE: The current manuscript aims to determine the prevalence, duration and bacterial diversity of bacteraemia following dental extractions using conventional culture-dependent methods and 16S rDNA pyrosequencing. METHODS: The study group included 8 patients undergoing dental extractions under general anaesthesia. Peripheral venous blood samples were collected at baseline, 30 seconds and 15 minutes after the dental extractions. Blood samples were analysed for bacteraemia applying conventional microbiological cultures under aerobic and anaerobic conditions as well as pyrosequencing using universal bacterial primers that target the 16S ribosomal DNA gene. RESULTS: Transient bacteremia was detected by culture-based methods in one sample at baseline time, in eight samples at 30 seconds, and in six samples at 15 minutes after surgical procedure; whereas bacteraemia was detected only in five blood samples at 30 seconds after dental extraction by using pyrosequencing. By applying conventional microbiological methods, a single microbial species was detected in six patients, and Streptococcus viridans was the most frequently cultured identified bacterium. By using pyrosequencing approaches however, the estimated blood microbial diversity after dental extractions was 13.4±1.7 bacterial families and 22.8±1.1 genera per sample. CONCLUSION: The application of 16S rDNA pyrosequencing underestimated the prevalence and duration of bacteraemia following dental extractions, presumably due to not reaching the minimum DNA required for PCR amplification. However, this molecular technique, unlike conventional culture-dependent methods, revealed an extraordinarily high bacterial diversity of post-extraction bacteraemia. We propose that microorganisms recovered by culture may be only the tip of an iceberg of a really diverse microbiota whose viability and potential pathogenicity should be further studied.

General anesthesia increases the risk of bacteremia following dental extractions.

OBJECTIVE: The influence of oral health status, the number of teeth extracted, and the anesthetic modality used is currently a matter of debate in the prevalence of bacteremia following dental extractions (BDE). The aim of the present study was to analyze the factors affecting the prevalence, duration, and etiology of BDE. STUDY DESIGN: Blood samples were collected from 210 patients at baseline, 30 seconds, 15 minutes, and 1 hour after performing dental extractions. Samples were processed in the Bactec 9240 and the subculture and further identification of the isolates were performed using conventional microbiological techniques. RESULTS: The prevalence of BDE at 30 seconds, 15 minutes, and 1 hour were 71%, 45%, and 12%, respectively. In the multivariate analysis, the "anesthetic modality" (local anesthesia versus general anesthesia) was the only variable related to BDE. CONCLUSION: General anesthesia represents a risk factor for BDE, increasing its prevalence and duration.

In vivo substantivity of 0.12% and 0.2% chlorhexidine mouthrinses on salivary bacteria.

The in vivo antimicrobial activity of 0.12% and 0.2% chlorhexidine (CHX) on the salivary flora up to 7 h after its application, using epifluorescence microscopy with the SYTO 9/propidium iodide dual staining, was evaluated. Fifteen volunteers performed a single mouthrinse with sterile water (SM-water), a single mouthrinse with 0.12% CHX (0.12% SM-CHX) and a single and double mouthrinse with 0.2% CHX (0.2% SM-CHX and 0.2% DM-CHX). Samples of saliva were taken at 30 s, and 1, 3, 5, and 7 h after each application. In comparison with SM-water, 0.2% CHX (SM and DM) showed a significant antibacterial effect up to 7 h after the mouthrinse, whereas this effect only persisted up to 5 h after the 0.12% SM-CHX mouthrinse. On comparing the two concentrations of CHX, significantly higher percentages of bacterial vitality were observed in all the saliva samples after the use of 0.12% CHX than after 0.2% CHX. On comparison of the 0.2% SM-CHX and 0.2% DM-CHX, significantly higher percentages of live bacteria were observed in the saliva samples taken at 1, 3, 5, and 7 h after the single mouthrinse compared with the double mouthrinse. The 0.2% CHX mouthrinse had the greatest antimicrobial activity on the salivary flora up to 7 h after its application, with a progressive recovery in bacterial vitality. The differences observed with respect to the 0.12% CHX mouthrinse demonstrate the influence of the concentration on its immediate antimicrobial activity and substantivity.