Vaccination and postexposure prophylaxis in heath-care workers      

M. N. GUTIÉRREZ, M. C. SÁENZ  

Health-care workers are an important professional group exposed to biological risks during their professional activity. The legal regulation of the occupational exposure, as well as the knowledge of occupational diseases, has facilitated the development of prevention measures for this group. Nowadays, vaccination against a number of infectious diseases is considered the most effective strategy of primary prevention. The recommended vaccines include those, according to age, included on adult immunization schedule, and vaccines against infectious diseases that can constitute a major risk, both for the professional and for the patient: chicken pox, rubella, HBV,.On the other hand, the occupational exposure to blood or other body fluids (transmission of HIV, HCV and HBV) is the main risk for health-care workers. Nevertheless, at this moment there is no effective immunoprophylaxis against any disease of this group, excepting HBV infection. Thus, occupational exposure prevention, chemoprophylaxis with anti-retroviral drugs when available, and exposure follow-up are the main strategies to decrease transmission risk.

Rev Esp Quimioter 2009:22(4):190-200 [pdf] 

Glycopeptide heteroresistance and tolerance in hospital grampositive isolates: “invisible” phenomena to the clinician with clinical implications?

L. AGUILAR, M. J. GIMÉNEZ, J. BARBERÁN  

This article reviews the concepts of heteroresistance and tolerance to glycopeptides in gram-positive bacteria isolated from hospitalised patients. Heteroresistance (resistant subpopulations among the total bacterial population of the strain, that can be selected by the treatment) and tolerance (capability of survival, but not growth, in the presence of usually lethal antibiotic concentrations) have in common several characteristics: 1) the absence of its determination in laboratory daily practice, 2) they implied a decrease in antimicrobial activity not reflected in MIC values (thus being “invisible” to clinicians in daily routine laboratory reports), 3) the decrease in antimicrobial activity may have clinical implications and 4) they affect a wide spectrum of gram positive bacteria in the hospital (Staphylococcus aureus, coagulase-negative staphylococci, enterococci and different estreptococcal species). The decrease produced in the bactericidal activity (that is critical for the treatment of bacteremias, endocarditis, meningitis and infections in immunocompromised patients) has clinical implications such as persistance of bacteremia, refractory bacteremia, relapse of infections and increased length of stay. Two strategies are possible to overcome tolerance and heteroresistance: addition of antibiotics to obtain bactericidal activity by synergism (key factor for which it should be taken into account antagonic combinations or high resistance to aminoglycosides when choosing the antibiotic regimen),or the use of bactericidal compounds to which gram-positive bacteria show susceptibility and absence of heteroresistance and tolerance (in contrast to glycopeptides), as is the case of lipopeptide daptomycin.

Rev Esp Quimioter 2009;22(4):173-179 [pdf]  

Recommendations in the empiric anti-infective agents of intra-abdominal infection

X. Guirao ,  J. Arias ,  J. M.ª Badía ,  J. A. García-Rodríguez ,  J. Mensa ,  F. Álvarez-Lerma ,  M. Borges ,  J. Barberán ,  E. Maseda ,  M. Salavert ,  P. Llinares ,  M. Gobernado y C. García Rey 

A significant number of patients with abdominal infection develop advanced stages of infection and mortality is still above 20%. Failure is multifactorial and is associated with an increase of bacterial resistance, inappropriate empirical treatment, a higher comorbidity of patients and poor source control of infection. These guidelines discuss each of these problems and propose measures to avoid the failure based on the best current scientific evidence.

Key words: Intra-abdominal infection. Guidelines. Anti-infective agents

Rev Esp Quimioter 2009:22(3):151-172  [pdf]

In vitro activities of posaconazole, fluconazole, itraconazole, ketoconazole and voriconazole against Candida glabrata

M. T. Blanco ,  J. Cañadas ,  P. García-Martos ,  P. Marín. ,  A. García-Tapia ,  M.J. Rodríguez 

This study has been conducted to asses the in vitro activity of the novel triazole antifungal agent posaconazole against 123 clinically important isolates of yeasts. Susceptibility was tested using the Sensititre YeastOne microdilution commercial method. Minimun inhibitory concentrations (MICs) were determined at the recommended endpoints and time intervals. The activity of posaconazole against Candida glabrata was compared with those of fluconazole, itraconazole, ketoconazole and voriconazole. The most susceptible species to posaconazole were C. albicans, C. parapsilosis, C. tropicalis and C. dubliniensis. Candida glabrata was the least susceptible. The percentage of strains with MIC for posaconazole ≥ 1 mg/L was 9%, all of them were C. glabrata. The species with MIC for itraconazole ≥ 0.5 mg/L were 36% (41 C. glabrata, 1 C. krusei, 1 C. guilliermondii, 1 C. ciferrii). Candida glabrata strains resistant to fluconazole, ketoconazole and voriconazole were 8%, 4% and 4%, respectively. Posaconazole exhibited good activity to the majority of Candida species. However, it was similar to itraconazole and less active than ketoconazole and voriconazole against C. glabrata.

Key words: Posaconazole. Yeasts. Candida glabrata.

Rev Esp Quimioter 2009:22(3):139-143  [pdf]

Antimicrobial susceptibility and molecular typing of Enterococcus faecium idolated from humans, chickens and environment in Canary Islands (Spain)

M. González ,  O. Afonso y M. T. Tejedor 

Comparative studies on antimicrobial susceptibility patterns and molecular typing of Enterococcus isolates of different origins provides valuable information concerning the epidemiology of enterococcal infections. We analyzed clinical isolates and we surveyed faecal samples of humans (hospitalised patients and healthy volunteers), faecal samples of poultry and environmental samples. A total of 68 E. faecium isolates were obtained: 43 from humans, 5 from poultry and 20 from water. We compared the antibiotic resistance patterns and pulsed field gel electrophoresis (PFGE) profiles of these strains. We used polymerase chain reaction (PCR) to examine them for the presence of 8 aminoglycoside resistance genes. Differences among percentages of antimicrobial resistance between clinical and non clinical isolates were found. All enterococci were susceptible to vancomycin and teicoplanin. Four aminoglycoside resistance genes were detected, most frequently ant(6)-Ia and aph(3’)-IIIa. Presence of isolates resistant to gentamicin but negative for all genes tested suggest that additional resistance genes may exist. VRE are still rare inside and outside hospitals in Gran Canaria (Spain). The high frequency of ampicillin resistance among clinical enterococci and the fact that several isolates share the same PFGE type were isolated from different wards of our hospital suggest that ampicillinresistant E. faecium are endemic in our Hospital.

Key words:Antimicrobial resistance. E. faecium. Polymerase chain reaction (PCR). Pulsed field gel electrophoresis(PFGE).

Rev Esp Quimioter 2009:22(3):120-126  [pdf]