Impacto de la clindamicina in vitro en la combinación clindamicina - ketoconazol sobre el exopolímero de biopelículas de candida spp de origen urogenital / Impact of in vitro clIndamycIn on the combInatIon of clIndamycIn and ketoconazole on exopolymer of candida spp bIofIlms of urogenItal orIgIn

La mucosa vaginal ha sido utilizada largamente para la administración de antimicrobianos destinados al tratamiento de infecciones endógenas del tracto genital inferior (IETGI) en mujeres embarazadas y no embarazadas. Candida spp elabora biopelículas (BP) y su formación es un proceso complejo que requiere que las células fúngicas establezcan múltiples interacciones con el medio. Las BP están rodeadas por un exopolímero (EPM) que puede restringir la actividad de anticuerpos, la difusión de sustancias y unirse a los antimicrobianos (AM), limitando su acción. Los antimicrobianos (AM) en general y los antimicóticos en particular (AMC) pueden tener dificultades para llegar a las células dentro del EPS. Muchas de las fórmulas que se emplean para el tratamiento empírico usan combinaciones inapropiadas con limitada o nula actividad sobre las biopelículas (BP). La presencia de moléculas que provoquen su inhibición anulando los inductores del EPM o por otro mecanismo, permitirá la actividad del AM específico. Objetivo: demostrar que la actividad de la clindamicina (CLI) en fórmula dual con ketoconazol (KET) actúa sobre BP Candida albicans (CA) y especies no albicans de Candida . (NAC). Métodos: estudiamos la actividad de clindamicina-ketoconazol (CK) sobre la adherencia y dispersión de BP de 8 aislamientos vaginales de CA y 7 de CNA. Se inocularon en 3 tubos con caldo Sabouraud y un dispositivo de vidrio para la formación de la BP según técnica ya descrita. Adherencia: Se incubaron durante 6 horas y se agregó una combinación de CK proveniente del material de óvulos, diluido convenientemente (62,5/260,4 ug/ml), a uno de los tubos de cada aislamiento tomándose como hora 0. Dispersión: esa misma dilución se agregó a otro tubo a las 16 horas. El tercer tubo quedó como testigo sin antimicrobianos. La lectura se efectuó con microscopio óptico a las 24 horas de agregada la combinación CK previa tinción con cristal violeta y se evaluaron con programas fotográficos. Por separado analizamos la actividad de CLI (62,5 ug/ml) y KET (260,4 ug/ml) con técnica similar. Seleccionamos las muestras de 7 pacientes que demostraron candidiasis vulvovaginal (CVV) y las estudiamos con la técnica de capas celulares. Se empleó la combinacion CK para el estudio de la adherencia y dispersión. Resultados: Adherencia se demostró poca influencia de CK en la adherencia con respecto a cada testigo. Dispersión: la influencia de CK se demostró en la mayoría de los aislamientos particularmente en los de CNA que mostraron una mayor presencia de EPM. Las hifas solo se observaron en 1/15 de los aislamientos de Candida spp cuando se agregó CK a las 16 horas. En las BP de las muestras clínicas no aparecieron hifas ni otro elemento micótico en 5/7 con respecto a los testigos. Conclusión: Según estos resultados el uso de una combinación de CK en BP de Candida spp, resulta en una adecuada penetración del AMC demostrada por la dispersión de la BP al cabo de 24 horas. Clindamicina no interfiere con la acción del ketoconazol sino que promovería su actividad anti-candida modificando posiblemente estructuras de superficie y la del EP por inhibición de las moléculas que facilitan la expresión del mismo. In vivo promueve la actividad inmunomoduladora que no se puede demostrar con este modelo in vitro. Su uso combinado en fórmulas duales facilitaría la actividad del AMC sobre Candida spp actuando como inhibidora o modificadora de las BP mediante la dispersión del EPM

The vaginal mucosa has been widely used for administering antimicrobial agents to treat endogenous infections of the lower genital tract in pregnant and non-pregnant women. Candida spp. elaborates biofilms, and its formation is a complex process requiring that fungal cells establish multiple interactions with the medium. Biofilms are surrounded by an exopolymer matrix that can restrict the activity of antibodies, the diffusion of substances, and be associated with antimicrobials, therefore limiting its actions. General antimicrobials and particular anti-mycotic agents can face difficulties to access the cells within the exopolymer matrix. Many formulas used for empirical treatment have improper combinations with limited or null activity on the biofilms. The presence of molecules that cause its inhibition, thus eliminating the exopolymer matrix inducers, or by other mechanism, will allow the specific antimicrobial activity. Objective: To show that the activity of clindamycin used in dual formula with ketoconazole works on Candida albicans biofilm and on non- albicans species of Candida . Methods: We studied the activity of clindamycin and ketoconazole regarding the adherence and dispersion of biofilms from eight vaginal isolates of C. albicans and 7 of non- albicans Candida . The isolates were inoculated in three tubes with Sabouraud agar and a glass device to form the biofilm according to a known technique. Adherence : Each isolate was incubated for a six-hour period and a combination of clindamycin and ketoconazole from the material of ovules was added and conveniently diluted to one of the tubes of each isolate (62.5/260.4 ug/mL), considering 0 hour. Dispersion: The same dilution was added to another tube after 16 hours. The third tube was used as a control without antimicrobials. The reading was carried out with an optical microscope after 24 hours that the clindamycin and ketoconazole combination had been added and colored with crystal violet. They were then evaluated using photographic programs. The activity of clindamycin (62.5 ug/mL) and ketoconazole (260.4 ug/mL) was analyzed alone with a similar technique. We chose vaginal samples from seven patients with vulvovaginal candidiasis and studied them through the cell layer technique. The clindamycin and ketoconazole combination was used for studying the adherence and dispersion. Results: Adherence: Little influence of clindamycin and ketoconazole was seen in adherence regarding each control. Dispersion: The clindamycin and ketoconazole influence was seen in most of the isolates, especially in those of non- albicans Candida that showed higher presence of exopolymer matrix . The hyphae were only seen in 1 of 15 isolates of Candida spp after the clindamycin and ketoconazole were added at the 16th hour. In biofilms of clinical samples, neither hyphae nor mycotic elements were seen in 5 of 7 compared with the controls. Conclusion: According to these results, the use of a clindamycin and ketoconazole combination in biofilms of Candida spp results in proper penetration of the antimicrobial agent, which is seen by the biofilm dispersion during 24 hours. Clindamycin does not interfere with the action of ketoconazole, but it would promote its anti- Candida activity and would possibly modify surface and EP structures through inhibition of the molecules that facilitate its expression. The in vivo model promotes the immunomodulatory activity that in vitro models do not. Its combined use in dual formulas would facilitate the antimicrobial activity on Candida spp, therefore working as an inhibitor or modifier of the biofilms after dispersion of the exopolymer matrix

Molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis clinical isolates

To evaluate the molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis (MH) clinical strains isolated from urogenital specimens. 15 MH clinical isolates with different phenotypes of resistance to fluoroquinolones antibiotics were screened for mutations in the quinolone resistance-determining regions (QRDRs) of DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) in comparison with the reference strain PG21, which is susceptible to fluoroquinolones antibiotics. 15 MH isolates with three kinds of quinolone resistance phenotypes were obtained. Thirteen out of these quinolone-resistant isolates were found to carry nucleotide substitutions in either gyrA or parC. There were no alterations in gyrB and no mutations were found in the isolates with a phenotype of resistance to Ofloxacin (OFX), intermediate resistant to Levofloxacin (LVX) and Sparfloxacin (SFX), and those susceptible to all three tested antibiotics. The molecular mechanism of fluoroquinolone resistance in clinical isolates of MH was reported in this study. The single amino acid mutation in ParC of MH may relate to the resistance to OFX and LVX and the high-level resistance to fluoroquinolones for MH is likely associated with mutations in both DNA gyrase and the ParC subunit of topoisomerase IV.

Caracterización clínica, microbiológica y de sensibilidad a antimicrobianos en pacientes con infección nosocomial del tracto urinario: cuatro años y medio de vigilancia epidemiológica / Clinical, microbiological and antimicrobial sensitivity in patients with hospital-adquired urinary tract infections: four and half years surveillance

Antecedentes: Las infecciones nosocomiales son entidades importantes por su aumento en la morbimortalidad y en los costos de tratamiento. En Medellín, Colombia, la del tracto urinario (ITU) es la segunda infección nosocomial más incidente, 16,3% del total. El objetivo del presente estudio fue realizar una caracterización de los aspectos clínicos y microbiológicos de los pacientes con infección nosocomial del tracto urinario en una clínica privada de Medellín, Colombia. Métodos: Estudio retrospectivo, longitudinal, descriptivo de las historias clínicas de los pacientes con infección nosocomial del tracto urinario entre enero/2005 y julio/2009. Resultados: Se diagnosticaron 134 casos en 130 pacientes (tasa institucional de 0,27 infecciones por 100 egresos), con alza de 0,21 por cada 100 egresos en 2005 a 0,59 en 2009. La mayoría de los pacientes fueron mujeres (67,7%), con edad promedio de 55 (IQ 27-72) años. Las comorbilidades más comunes fueron hipertensión arterial (48,5%) y enfermedad renal crónica (16,3%). Los gérmenes más comunes fueron E. coli (54,9%) y K. pneumoniae (12,8%). Hay alta proporción de resistencia a ciprofloxacina, ampicilina/sulbactam y trimetoprim/sulfametoxazol. Conclusión: La ITU nosocomial es una entidad relativamente común en la institución estudiada, aunque su tasa es consistentemente inferior a la encontrada en estudios similares. Para el manejo empírico de esta infección parece recomendable iniciar con amikacina o ceftriaxona, utilizando imipenem o meropenem en pacientes sépticos con comorbilidad seria o con alto riesgo de gérmenes multirresistentes. Para el tratamiento de ITU nosocomial por E. coli, la amikacina y la gentamicina parecen buenas opciones, al igual que la ceftriaxona.

Background: Hospital-acquired infections are important conditions because of their linked increase in morbimortality and in treatment costs. The objective of this study was to perform a characterization of clinical and microbiological aspects of patients with hospital-acquired urinary tract infection on a University Hospital in Medellín, Colombia. Methods: A retrospective, descriptive study was performed, in which the medical records of all patients such an infection were reviewed. Results: A total of 134 infections in 130 patients were detected (rate : 0,27 infections per every 100 hospital discharges), with an upward behavior from 0,21 cases/100 dischrges in 2005 to 0,59 in 2009. Most of the patients (67,7%) were female, with a median age of 55 (IQ 27-72) years. The most commonly found commorbidities were arterial hypertension (48,5%) and chronic kidney disease (16,3%). The most commonly isolated agents were E. coli (54,9%) and K. pneumoniae (12,8%). High rates of resistance t o ci pr of l oxaci n, ampi ci l i n/ sul bact am y t r i met opr i m/sulfametoxazol were found. Discussion: Our study is one of the few characterizations of hospital-acquired urinary tract infection in Colombia; it is shown that our ecology is, up to a point, similar, to that found by international authors, although a higher prevalence of E. coli was found. It is important to recall the relatively high resistance rates to first-line antibiotics. [Jiménez JG, Gaviria ME, Balparda JK, Castrillón DM, Marín AE, Escobar E. Clinical, microbiological and antimicrobial sensitivity in patients with hospital-adquired urinary tract infections: four and half years surveillance. MedUNAB 201 1; 14:145-150].

Characterization of low molecular weight antimicrobial peptide from human female reproductive tract.

Background & objectives: The mechanisms that protect female upper genital tract from ascending infection by microbes present in vagina are only partially understood. It is expected that epithelial cells in mucosal surfaces and their secretions directly interfere with microbial colonization and invasion. This study was aimed to demonstrate the expression of 2 kDa antimicrobial peptide which was identified and purified from female genital tract tissues using chromatographic techniques. Methods: Low molecular weight proteins were isolated from human female reproductive tract tissues obtained from premenopausal women. Antimicrobial activity of these LMW proteins was assessed against different reproductive tract pathogens viz., Neisseria gonorrhoeae, Group B streptococcus, Gardnerella vaginalis, Escherechia coli and Candida albicans. The expression of these peptides were also documented in reproductive tract tissues with the help of hyperimmune sera raised against the rabbits. The purified peptide was characterized by N-terminal sequencing. Results: Immunohistochemical and immunofluorescence studies demonstrated that 2 kDa peptide was expressed in the stratified squamous epithelial cells of the ectocervix while it was absent in columnar epithelial cells of upper genital tract. Upregulation of the expression of this peptide was observed in patients of chronic non-specific cervicitis and acute on chronic cervicitis. This purified antimicrobial peptide also showed broad spectrum antimicrobial activity against different reproductive tract pathogens. Interpretation & conclusions: Considering the emerging bacterial resistance against conventional antibiotics, isolation and understanding of the expression of antimicrobial peptides from female reproductive tissue extracts may provide some leads towards the development of strategies for the treatment of reproductive tract infections.