Enfermedades de transmisión sexual e infección por VIH: interacción epidemiológica y clínica / Sexual transmitted diseases and HIV infection: clinical and epidemiological interaction

Objetivo: Revisar y recopilar los conocimientos sobre la interacción entre la infección por el virus de la inmunodeficiencia humana (VIH) y las demás enfermedades de transmisión sexual (ETS), tanto desde el punto de vista clínico como epidemiológico. Fuentes revisadas: Base de datos PubMed-Medline desde 1982 y textos de consulta y guías de SIDA y de ETS. Selección de estudios: En la base de datos, editoriales, originales o revisiones en cualquier idioma, con resumen en español, francés o inglés, cuyo título (traducido al inglés en su caso) incluya los términos "HIV" y "STD" (o el nombre de cualquier ETS). Recopilación de datos: Todo sobre transmisión sexual del VIH (en presencia o no de ETS), clínica, diagnóstico o tratamiento de ETS en infectados por VIH, prevalencia de VIH en sujetos con ETS o profilaxis de la transmisión sexual del VIH. Síntesis de datos: Transmisión sexual del VIH por relaciones heterosexuales y homosexuales y su modificación en presencia de ETS coexistentes u otros factores; prevalencia y peculiaridades en la clínica, diagnóstico y tratamiento de las diferentes ETS en infectados por el VIH; importancia del papel del personal sanitario en la prevención de la transmisión sexual del VIH. Conclusiones. La infección VIH y demás ETS comparten conductas y factores de riesgo, y se potencian mutuamente en su transmisión y evolución. La infección VIH, debido al deterioro inmunológico que produce, puede alterar profundamente las manifestaciones clínicas y la respuesta terapéutica de las demás ETS. Es necesaria una labor activa de todo el personal sanitario en la detección de la infección y en la educación de la población en riesgo, una tarea que la Sanidad Militar debería considerar prioritaria (AU)

Synergy of different antibiotic combinations in biofilms of Staphylococcus epidermidis.

The in vitro effect of nine antibiotic combinations was investigated in Staphylococcus epidermidis biofilms using ATP-bioluminescence for viable bacterial cell quantification. Four slime-producing (SP) strains were used to form biofilms 6, 24 and 48 h old. These biofilms were exposed for 24 h to antibiotics at 4 x, 2 x, 1 x and 0.5 x MIC. Combinations involving tetracycline together with another antibiotic were the most efficient at the biofilm age and concentration range under study. The combination vancomycin-rifampicin produced the highest bactericidal effect on 6 h biofilms at 4 x MIC, but this effect decreased dramatically in older biofilms. To detect possible antibiotic synergy in combinations that had a significant killing effect, antibiotics were studied not only in combination but also individually. Synergic effects were observed in all the combinations tested. Differences between the effect in combination and the sum of individual antibiotic effects (degree of synergy) were significant (mostly P< 0.001) and exceeded 1 log10 cfu/mL in the majority of cases. In 48 h biofilms, antibiotics caused a significant bactericidal effect when applied in combination, but never when used individually. These results indicate that the biofilm test applied allows the detection of synergy between antibiotics and suggests that this assay could be useful in clinical and extensive synergy studies on S. epidermidis biofilms.

A simple infection model using pre-colonized implants to reproduce rat chronic Staphylococcus aureus osteomyelitis and study antibiotic treatment.

Staphylococcus aureus biofilms formed on medical implants represent a serious problem, being difficult to eradicate with antibiotic therapy and leading to chronic infections. Simplified in vivo and in vitro antibiotic susceptibility assays using biofilm bacteria are needed. In this work, a novel chronic osteomyelitis infection model was developed in rats in the absence of bacterial suspension, requiring the use of only 10(6) bacteria in biofilms at the site of surgery, with a full success in reproducing infection. Stainless-steel implants pre-colonized for 12 h with a highly adherent S. aureaus isolate were introduced into the rat tibiae. In animals not submitted to antibiotic treatment, infection was found in the implants and spread to bone in all cases, indicating the high efficacy of the model to reproduce osteomyelitis. The effect of a 21-day treatment with cefuroxime, vancomycin, tobramycin or ciprofloxacin on infection was studied in this model 42 days after surgery. Bone colonization was inhibited by vancomycin and cefuroxime. Cefuroxime (the most efficient antibiotic, able to sterilize 1 out of 8 implants) reduced the number of bacteria in biofilms adhered to implants at a higher extent than vancomycin, trobramycin and ciprofloxacin. Analogous observations were made in this work in vivo and in vitro on the relative antibiotic efficacy against S. aureus biofilm bacteria. suggesting the usefulness of both tests as a potential tool to study antibiotic suceptibility, and the need for new antimicrobials against these bacteria.

Antibiotic susceptibility assay for Staphylococcus aureus in biofilms developed in vitro.

Four slime-producing isolates of Staphylococcus aureus were used in an antibiotic susceptibility assay for biofilms developed on 96-well polystyrene tissue culture plates. The study involved 11 antibiotics, two biofilm ages (6 and 48 h), two biofilm growth media (tryptone soy broth (TSB) and delipidated milk) and three antibiotic concentrations (4 x MBC, 100 mg/L and 500 mg/L). ATP-bioluminescence was used for automated bacterial viability determination after a 24 h exposure to antibiotics, to avoid biofilm handling. Under the conditions applied, viability in untreated biofilms (controls) was lower when biofilm growth was attempted in milk rather than in TSB. Various antibiotics had a greater effect on viability when used at higher (> or =100 mg/L) antibiotic concentrations and on younger (6 h) biofilms. Increased antibiotic effect was observed in milk-grown rather than TSB-grown biofilms. Phosphomycin and cefuroxime, followed by rifampicin, cefazolin, novobiocin, vancomycin, penicillin, ciprofloxacin and tobramycin significantly affected biofilm cell viability at least under some of the conditions tested. Gentamicin and erythromycin had a non-significant effect on cell viability. Transmission electron microscopy revealed that cells at the inner biofilm layers tend to remain intact after antibiotic treatment and that TSB-grown biofilms favoured a uniformity of cell distribution and increased cell density in comparison with milk-grown biofilms. A reduced matrix distribution and enhanced cell density were observed as the biofilm aged. The S. aureus biofilm test discriminated antibiotics requiring shorter (3 h or 6 h) from those requiring longer (24 h) exposure and yielded results which may be complementary to those obtained by conventional tests.

[Survival with no sequelae after near-drowning with very poor signs for prognosis including persistent bilateral non-reactive mydriasis]. / Supervivencia sin secuelas tras casi-ahogamiento con muy malos signos pronósticos, incluida midriasis arreactiva bilateral persistente.

INTRODUCTION: The outcome of cases of near-drowning and initially poor prognostic signs are usually discouraging because of the severity of the consequent encephalopathy in most survivors. However, good recovery has been described, in spite of bad prognostic factors initially. It is difficult to establish the predictors of poor outcome which would enable one to decide when to establish and maintain advanced cardio-pulmonary resuscitation measures (CPR), since each case of near-drowning is different. CLINICAL CASE: A four year old boy survived near-drowning in cold water without sequelas but with initial signs of very poor prognosis, including prolonged immersion time, coma, severe metabolic acidosis, hyperglycemia and persistent bilateral arreactive mydriasis. DISCUSSION: The beneficial effect of hypothermia is well known, and explains (at least partially) survival in cases of apparently irreversible near-drowning. Potential benefits are reduced metabolic demand which prevents the adverse effects of hypoxia and the 'diving reflex' which short-circuits the blood supply to vital organs such as the brain and heart. We consider that the persistently arreactive pupils were not due to hypoxia, but rather to bilateral uncal compression of the third cranial nerves due to cerebral edema secondary to initial hypoxia and water intoxication. CONCLUSION: This observation is yet another argument for the establishment and maintenance of aggressive manoeuvers of CPR and treatment in all children who have nearly-drowned, independently of the apparent seriousness or irreversibility.

Application of a rat osteomyelitis model to compare in vivo and in vitro the antibiotic efficacy against bacteria with high capacity to form biofilms.

A rat experimental osteomyelitis model was used to study the efficiency of antibiotics on biofilm bacteria adhered to implants in relation to the efficiency obtained in vitro. In the osteomyelitis model, 10(4) bacteria of the strain variant used for the in vitro studies (a slime-producing variant of Staphylococcus aureus) were inoculated into the rat tibia at surgery, after implanting a stainless steel canula precolonized for 12 h with this strain. After 5 weeks, a 21-day antibiotic treatment was applied (using cefuroxime, vancomycin, or tobramycin). Subsequently, implant and tibia were studied for presence of bacteria. In this osteomyelitis model, cefuroxime inhibited bone colonization and reduced the number of bacteria in metal and bone at a higher degree (P < 0.05) than vancomycin and trobramycin (the latter antibiotic did not have this reduction effect). The in vitro assay was applied using three concentrations of each antibiotic (8, 100, and 500 microg/ml) and 6-, 24-, and 48-h biofilms. Bacterial viability was evaluated by ATP-bioluminescence after 24 h of antibiotic treatment. In this in vitro assay, cefuroxime significantly (P < 0.05) reduced in all cases the number of viable bacteria in biofilms, tobramycin did not affect viability, and vancomycin affected viability except at the lowest concentration used (8 microg/ml, i.e., 8x the minimal bactericidal concentration of this antibiotic) when facing the oldest (48 h) biofilm. These results demonstrate the usefulness of the osteomyelitis model applied in providing evidence for a close correlation between the in vitro and in vivo findings on the effect of three antibiotics under study.

Bacterial contamination of allografts.

The risk of bacterial infection through allogenic bone transplantation is one of the major problems facing tissue banks. The purpose of this study is to report the contamination rate in 987 grafts obtained under strictly aseptic conditions, between 1989 and 1992. The grafts were stored at -80 degrees C (cortical bone and tendons) and -40 degrees C (cancellous bone). The overall contamination rate was 6.6%, with Gram-positive bacteria responsible for 80% of the positive cultures. We discuss the sources of contamination, the most frequently isolated bacteria and the steps in the donation and transplantation procedures that help to reduce the risk of contamination. We conclude that the methods of acquisition, processing and storage of tissues are effective in making sterile allografts available.

Bacterial contamination of allografts.

The risk of bacterial infection through allogeneic bone transplantation is one of the problems facing tissue banks. The purpose of this study is to report the contamination rate in 987 grafts obtained under strictly aseptic conditions, between 1989 and 1992. The grafts were stored at -80 degrees C (cortical bone and tendons) and -40 degrees C (cancellous bone). The overall contamination rate was 6.6%, with Gram-positive bacteria responsible for 80% of the positive cultures. We discuss the sources of contamination, the most frequently isolated bacteria and the steps in the donation and transplantation procedures that help to reduce the risk of contamination. We conclude that the methods of procurement, processing and storage of tissues are effective in making sterile allografts available.

[Renal amyloidosis in a case of Crohn disease with colonic and rectal involvement]. / Amiloidosis renal en un caso de enfermedad de Crohn con afectación de colon y recto.

A clinical case characterized by renal amyloidosis, Crohn's disease of the colon and rectum, multiple chronic anal fistulae and ankylosing spondylitis is reported. This association has been infrequently recognized. In this patient Crohn's disease became manifest at 20 years of age and underwent a chronic and relapsing course. Proteinuria and renal amyloidosis were detected after eight years of evolution. Panproctocolectomy was performed. The patient progressed satisfactorily and six months later he remains asymptomatic, free from medication and with normal creatinine clearance. The authors recommend early surgical treatment on the diseased intestinal segment once the association has been diagnosed and before serious impairment of renal function has occurred.

Recurrent pulmonary embolism due to hydatid disease of heart. Study of 3 cases, one with intermittent tricuspid valve obstruction (atrial pseudomyxoma).

Three cases of pulmonary hypertension caused by hydatid emboli from the right side of the heart are described; cardiac catheterisation was performed in 2. One case was confirmed at operation and 2 at necropsy. The pulmonary emboli were caused by hydatid vesicles in all 3 cases and in none was there pulmonary thrombosis; free scolices were found in the pulmonary alveoli in 2. In 1 patient with repeated syncopal attacks there was a pedunculated cyst in the right atrium which was though to have intermittently obstructed the tricuspid valve. Gamma radiography, angiocardiography, and necropsy suggested a mechanical cause for the pulmonary hypertenion with no vasoconstrictive element. The surgical patient was alive and well 18 months later.