Biomedical subjects
Publications and source records attributed to E Bouza.
A disseminated Scedosporium apiospermum infection was diagnosed in a woman with severe asthma and treated with corticosteroids. This fungi is resistant to fluconazole and amphotericin B. The infection was refractory to itraconazole, but responded successfully to voriconazole. A review of the literature is provided.
Resistance of Streptococcus pneumoniae to antimicrobial agents shows geographical variation and also depends on serotype, patient age and sample origin. Factors affecting antibiotic resistance in S. pneumoniae were studied from results of a multicentre susceptibility study of 12 antimicrobial agents, carried out in 14 Spanish hospitals between May 1996 and April 1997. The most frequent serotypes were serotypes 6 (14.8%), 19 (11.8%), 23 (10.5%), 3 (9.9%), 9 (8.0%), 14 (8.0%), 15 (3.9%) and 11 (3.2%); 9.6% of isolates were not typeable. The remaining 25 serotypes constituted 20.2% of strains. Penicillin resistance was more prevalent in serotypes 14 (88%), 23 (66%), 9 (62%) and 6 (57%), whereas erythromycin resistance was more prevalent in serotypes 6 (68.5%), 15 (61.4%), 14 (49.5%), 19 (42.7%) and 23 (39.3%). Serotypes 6 and 19 were the serotypes most commonly isolated from both children and adults, although with different proportions (24.0% and 19.2% of isolates from children were serotype 6 and 19, respectively, with the corresponding figures for isolates from adults being 13.6% and 11.5%, respectively). The rates of resistance of pneumococcal strains to penicillin and cefuroxime were significantly higher in strains from children than in those from adults (resistance to penicillin, 50.4% in children and 37.0% in adults; resistance to cefuroxime, 62.4% in children and 45.6% in adults). There was significantly more resistance to erythromycin in middle ear isolates (48.9%) than in blood isolates (27%). The prevalence of resistance to beta-lactams showed a seasonal pattern, with higher rates in summer and winter, proportional to the magnitude of resistance. Susceptibility to macrolides did not vary seasonally. Our results stress the relative importance that geographical, temporal (seasonality), patient (sample type, origin, age group) and bacterium-related (serotype) factors have on the variations in susceptibility observed among different pneumococcal clinical isolates.
Two hundred fifty isolates of Mycobacterium tuberculosis were evaluated for susceptibility to ciprofloxacin, ofloxacin, levofloxacin, grepafloxacin, trovafloxacin, and gemifloxacin (SB-265805). Levofloxacin, ciprofloxacin, and grepafloxacin showed the greatest activity (MIC for 90% of strains tested [MIC(90)] 1 microg/ml), although ofloxacin also showed good activity, with an MIC(90) of 2 microg/ml. Trovafloxacin and gemifloxacin showed lower in vitro activity, with MIC(90)s of 64 and 8 microg/ml, respectively.
Pseudomonas (formerly Flavimonas) oryzihabitans is an uncommon pathogen that may cause catheter-associated infections. Although it has occasionally been isolated from the environment, the source of human infection has not previously been documented. We describe an AIDS patient who developed Pseudomonas oryzihabitans bacteremia due to colonization of a Hickman catheter. The patient reported having strictly followed the recommendations for catheter hygiene. The only flaw detected was the use of a synthetic bath sponge in the shower. The sponge was cultured and yielded P. oryzihabitans among other nonfermentative, gram-negative bacilli. To determine the prevalence of P. oryzihabitans in sponges, we cultured 15 samples from unrelated households. The microorganism was isolated from 3 of the 15 samples. Molecular typing by arbitrarily primed PCR (AP-PCR) was performed with the environmental and clinical isolates. Three different profiles were obtained for the six isolates analyzed from the patient's sponge. The strain from the AIDS patient was identical to one of those from his sponge and was different from all the remaining strains. The AP-PCR typing results were subsequently confirmed by pulsed-field gel electrophoresis. It can be concluded that sponges are occasionally colonized by P. oryzihabitans. For the first time a probable source of an indwelling catheter contamination with this bacterium has been found. Patients carrying these devices should avoid using sponge-like materials, as these are suitable environments for nonfermentative, gram-negative bacilli.
Most cases of nosocomial bacteremia are catheter related, and coagulase-negative staphylococci (CoNS) are the microorganisms most frequently associated with these infections. Subtle morphological differences are frequently found among CoNS colonies cultured from infected catheters. The aim of this study was to analyze the significance of the morphological heterogeneity observed in these CoNS populations. With this purpose in mind, the clonal composition of the CoNS populations obtained from a selection of nine catheters was analyzed by two different molecular techniques, arbitrarily primed-PCR and DNA macrorestriction analysis by pulsed-field gel electrophoresis. Twenty CoNS morphotypes were included for analysis, and four single colonies representative of each morphotype were selected. Morphological differences between colonies were found to correlate in all cases with differences at the molecular level. Unique fingerprints were also obtained for some isolates which were indistinguishable from other representatives of the same morphotypes. Differences in the molecular patterns among the isolates were associated in most of the cases with differences in the antimicrobial susceptibility patterns. The frequent isolation of polyclonal CoNS populations from catheters, with heterogeneous antimicrobial susceptibility patterns, has relevant epidemiologic and therapeutic implications in the context of catheter-related infections.
The MB/BacT mycobacterium detection system was evaluated for its performance in the susceptibility testing of Mycobacterium tuberculosis. Eighty-three M. tuberculosis isolates were processed. Results for all isoniazid-, rifampin- and streptomycin-susceptible, isoniazid-resistant, and rifampin-resistant M. tuberculosis isolates with the MB/BacT system agreed 100% with those obtained by the agar proportion method. The agreements between the two methods for streptomycin- and ethambutol-resistant isolates were 96.4 and 90.4%, respectively. The susceptibility test results were obtained in 7 days, on average. These data demonstrate that the MB/BacT system is an accurate, nonradiometric method for rapid susceptibility testing of M. tuberculosis.
We evaluated the new automated VITEK 2 system (bioMérieux) for the identification and antimicrobial susceptibility testing of enterococci. The results obtained with the VITEK 2 system were compared to those obtained by reference methods: standard identification by the scheme of Facklam and Sahm [R. R. Facklam and D. F. Sahm, p. 308-314, in P. R. Murray et al., ed., Manual of Clinical Microbiology, 6th ed., 1995] and with the API 20 STREP system and, for antimicrobial susceptibility testing, broth microdilution and agar dilution methods by the procedures of the National Committee for Clinical Laboratory Standards. The presence of vanA and vanB genes was determined by PCR. A total of 150 clinical isolates were studied, corresponding to 60 Enterococcus faecalis, 55 Enterococcus faecium, 26 Enterococcus gallinarum, 5 Enterococcus avium, 2 Enterococcus durans, and 2 Enterococcus raffinosus isolates. Among those isolates, 131 (87%) were correctly identified to the species level with the VITEK 2 system. Approximately half of the misidentifications were for E. faecium with low-level resistance to vancomycin, identified as E. gallinarum or E. casseliflavus; however, a motility test solved the discrepancies and increased the agreement to 94%. Among the strains studied, 66% were vancomycin resistant (57 VanA, 16 VanB, and 26 VanC strains), 23% were ampicillin resistant (MICs, >/=16 microgram/ml), 31% were high-level gentamicin resistant, and 45% were high-level streptomycin resistant. Percentages of agreement for susceptibility and resistance to ampicillin, vancomycin, and teicoplanin and for high-level gentamicin resistance and high-level streptomycin resistance were 93, 95, 97, 97, and 96%, respectively. The accuracy of identification and antimicrobial susceptibility testing of enterococci with the VITEK 2 system, together with the significant reduction in handling time, will have a positive impact on the work flow of the clinical microbiology laboratory.
PURPOSE/METHODS: The purpose is to discuss the surgical result in a case with chronic progressive external ophthalmoplegia (CPEO) associated with strabismus and diplopia. The authors present a patient with mitochondrial myopathy and CPEO who was treated using adjustable recessions with local anaesthesia. RESULTS/CONCLUSIONS: Five months after surgery improvement in ductions were maintained and there was no diplopia or torticollis. We support operating these cases with CPEO associated with strabismus. The adjustable suture technique allowed us a satisfactory result in immediate postoperative.
As high heterogeneity of plasma composition may be responsible for interference with HIV-1 viral load determination by the bDNA assay, the potential interference caused by a number of plasma components was examined. Among the biochemical substances assayed, cholesterol, bilirubin, and triglycerides did not affect viral load quantification. Hemoglobin did not interfere with the assay at concentrations lower than or equal to 14 g/dl. Above this concentration, measurements decreased by up to 0.78 log, but these hemoglobin levels do not usually occur in the clinical setting. None of the antiretroviral drugs assayed (AZT, dDC, d4T, 3TC and Indinavir) interfered with the measurement. HIV bDNA is a robust assay even in those frequent circumstances in which plasma composition differs notably from normal.
Toxigenic Clostridium difficile is the aetiologic agent of most cases of antibiotic-associated diarrhoea and pseudomembranous colitis. The present standard method for C. difficile diagnosis is a cytotoxicity assay, performed on human fibroblast cultures. It is time consuming and requires special facilities. A nested-PCR assay detecting toxin B gene within a few hours was designed. One hundred and two stool samples were collected during four months. All samples were processed for toxin B-PCR, cultured for C. difficile and tested for cytotoxicity. This approach achieved 99% concordance with the cytotoxic assay. The sensitivity and specificity for the new PCR assay were 96.3% and 100% respectively. The procedure described is easy to perform, does not require special equipment and has produced excellent results. It deserves serious consideration for routine clinical microbiology laboratory use.
The novel 8-methoxyquinolone, moxifloxacin (Bay 12-8039), was compared with ciprofloxacin and eight other antimicrobials for activity against 425 strains Gram-positive clinical isolates, including 73 methicillin-resistant staphylococci, 35 vancomycin-resistant enterococci, and 80 penicillin- or eythromycin-resistant streptococci. Overall, 82% of the strains were inhibited at < or = 2 micrograms/mL. Moxifloxacin was more active than ciprofloxacin against staphylococci (8- to 32-fold), enterococci (0- to 16-fold), pneumococci (16-fold) and other streptococci (4- to 16-fold) when MIC90 results were compared. Moxifloxacin demonstrated good activity against all Gram-positive isolates tested except for ciprofloxacin-resistant enterococci (MIC90, 32 micrograms/mL) and methicillin-resistant staphylococci (MIC90, 8 micrograms/mL). Clinical trials should be initiated to define the role of this new quinolone.
The emergence of some strains of common pathogens of community acquired pneumonia resistant to one or more of the frequently used antimicrobials is becoming widespread. The clinical significance and implications of these resistance patterns are, however, unclear. Studies of the clinical progress of patients with pneumonia or bacteraemia infected with penicillin-resistant organisms show that patients frequently recover when treated with penicillins or cephalosporins. Beta-Lactam drugs and macrolides are still associated with clinical success in lower respiratory tract infections despite increasing resistance to these agents in vitro. Therefore, when making therapeutic choices, in vitro resistance data cannot always be used to predict clinical outcome. Infections caused by resistant organisms can usually be successfully treated using traditional therapeutic approaches.
Identification of the aetiological agents responsible for bone and joint infections requires either hard to obtain specimens that are easy to interpret, or easy to obtain specimens of difficult interpretation. Isolates obtained by blood cultures, arthrocentesis, or trephine or surgical biopsy bone samples are usually clinically significant. In contrast, samples obtained from sinus tracts or through open wounds are very often easy to obtain but difficult to interpret. Micro-organisms such as Staphylococcus epidermidis are the most common cause of infections around prosthetic joint materials but are usually of little significance when obtained from the sinus tract of a patient with chronic osteomyelitis of the tibia without osteosynthesis. Other micro-organisms to be interpreted with caution include Corynebacterium spp. and Enterococcus spp. The most important families of antimicrobial agents and their utility in bone and joint infections are briefly reviewed at the end of the chapter. Bone and joint infections require long-term antimicrobial therapy based on the correct diagnosis and the appropriate selection of antimicrobial treatment.
Both acute and chronic osteomyelitis are causes of rising concern, mainly because of the increasing number of traumatic accidents, the appearance of new groups of patients at risk, the widespread use of prosthetic devices and the emergence of new patterns of antimicrobial resistance. Classification systems, clinical features and risk factors will be reviewed. Diagnosis is usually clinical and microbiological, but imaging techniques such as plain radiography, radionuclide imaging, computed tomography and magnetic resonance imaging are commonly used. Decisions regarding the best imaging modality can be challenging and should reflect the location of the suspected infection and any associated illnesses or bone disorders. Osteomyelitis is characteristically recurrent, needs multiple surgical interventions and is resistant to short courses of therapy. The application of more precise diagnostic techniques and the availability of non-toxic, highly efficacious oral antimicrobial agents frequently permit a long-term ambulatory approach. The optimal length of therapy has not been established.
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OBJECTIVE: To characterize the epidemiological relationships among Stenotrophomonas maltophilia isolates in the neonatology unit of our institution over a 4-month period in which an increased number of isolates was observed. SETTING: The neonatology ward in a 2,000-bed university hospital in Madrid, Spain. DESIGN: A retrospective molecular epidemiological analysis using three different typing methods, arbitrarily primed polymerase chain reaction (PCR), pulsed-field gel electrophoresis, and enterobacterial repetitive intergenic consensus-PCR, was performed with 11 isolates obtained from seven neonates over a 4-month period. Presumed unrelated isolates also were included as controls. A similarity dendrogram was obtained, to analyze the genetic relatedness among the isolates. RESULTS: All isolates from the neonates, except one, showed a remarkably high homology among their typing patterns for the three methods assayed and clustered in the relatedness dendrogram at 96% similarity. The unrelated strains selected as controls were unclustered. The index case was considered to be a newborn who had an S. maltophilia isolate from a culture drawn on the day of admission to the neonatology unit and which was included in the clustered similarity group. CONCLUSIONS: Such a high genetic similarity among the isolates, together with the presence of an index case who had been colonized or infected by S. maltophilia before arrival at our institution, constitutes the first evidence of nosocomial cross-transmission of this microorganism.
The pandemic impact of HIV has changed the clinical spectrum of STDs all over the world. The incidence and frequency of STDs in the different global geographic areas demonstrate the diagnostic and treatment capabilities of various local and national health systems and is simultaneously informing about the sexual behaviours of the population. The purpose of this study was to determine the frequency of curable STDs (herpes, chlamydia, gonorrhoea, syphilis, trichomoniasis) in a hospital-based STD clinic in Madrid, Spain during a 4-year period. Patients were referred mainly from the emergency department, gynecological wards, and family planning (61%) as well as from the HIV-hospital unit (31 beds) and outpatient department (39%). The total number of patients seen was 952 (243 men, 709 women) with an annual average of 238 patients per year. Of these, 139 (14.6%) were HIV-patients and 813 (85.4%) non-HIV patients. In non-HIV patients, STDs were identified in 493 cases (54.2%). In HIV-patients, STDs were diagnosed in 108 cases (77.7%; p < or = 0.001). Two or more STDs were more prevalent in HIV than non-HIV patients. The frequency of STDs in both HIV and non-HIV patients were vulvovaginal candidiasis, 47.8%:57.2%; syphilis, 11.7%:1.4% (p < or = 0.05); gonorrhea, 5.3%:3.9%; Gardnerella vaginosis, 6.3%:4.8%; genital chlamydia, 6.3%:9.06%; trichomoniasis, 17%:6.5% (p < or = 0.05); and genital herpes, 20.2%:5.3% (p < or = 0.05).