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J A Vazquez

Publications and source records attributed to J A Vazquez.

At least 19 recordsLinked to original sources
PubMed2003

Combination antifungal therapy against Candida species: the new frontier--are we there yet?

In the past decade, we have seen a significant increase in the incidence of invasive fungal infections. In addition, opportunistic fungal infections resistant to antifungal agents have become increasingly common and their frequency will more than likely continue to increase. The antifungal armamentarium for the treatment of serious fungal infections remains limited. A possible approach to overcoming antifungal drug resistance and high mortality rates seen in severe fungal infections is to combine two or three classes of antifungals, especially if the drugs have different mechanisms of action. The unique properties of newer antifungals now provide us with the opportunity to investigate antifungal combinations that may become the standard of care for serious fungal infections. Combinations of new agents along with more traditional antifungals have now been shown to possess some synergistic or at least additive activity against Candida in clinical trials. On the other hand, caution is still needed since other antifungal combinations have demonstrated antagonistic activity in vitro. Well-controlled clinical trials are needed to define the most efficacious antifungal regimen. Furthermore, these trials should also evaluate the side effect potential of combination regimens and the pharmacoeconomic impact these regimens may have. Thus, while much optimism exists for combination therapy, there is much yet to be done.

Antifungal Agents↗
PubMed2003

Impact of meningococcal vaccination with combined serogroups A and C polysaccharide vaccine on carriage of Neisseria meningitidis C.

Two studies of meningococcal carriage state were carried out in Galicia (Spain) before and after a mass vaccination campaign between December 1996 and January 1997 against Neisseria meningitidis serogroup C with meningococcal serogroups A and C polysaccharide vaccine. The studies covered two areas with different incidence rates of meningococcal disease in 1996 (high and low incidence). Carriage rates of serogroup C showed a decrease in both areas, 47 and 65 % respectively, before and after the vaccination. Results showed a decrease in carrier state in the age groups 10-14- and 15-19-year-olds, but not in the 5-9-year-olds. These results demonstrate the effect of immunization on the reduction of the carriage state.

Adolescent↗
PubMed2001

Evolution of antifungal susceptibility among Candida species isolates recovered from human immunodeficiency virus-infected women receiving fluconazole prophylaxis.

The effect of fluconazole on the susceptibility of Candida isolates recovered from women infected with human immunodeficiency virus (HIV) was evaluated in a randomized, double-blind, placebo-controlled trial. Women with CD4(+) cell counts of < or =300 cells/mm(3) received either fluconazole (200 mg/week) or placebo as prophylaxis. The antifungal susceptibility of specimens was evaluated. One patient who received fluconazole and 2 patients assigned to placebo had Candida albicans isolates recovered that were resistant to fluconazole (MIC, > or =64 microg/mL). Eleven patients assigned fluconazole and 4 patients assigned placebo had non-albicans Candida strains (all Candida glabrata) recovered that were resistant to fluconazole. There was significant azole cross-resistance among the non-albicans Candida species isolates. Although the rate of azole resistance did not significantly increase after fluconazole prophylaxis, there was a trend toward more in vitro azole resistance in C. glabrata isolates from patients assigned fluconazole. Moreover, the majority of resistant vaginal isolates of Candida species were recovered after initiation of open-label fluconazole use.

AIDS-Related Opportunistic Infections↗
PubMed2001

Trichosporon asahii, a non-Candida yeast that caused fatal septic shock in a patient without cancer or neutropenia.

Trichosporon asahii (formerly Trichosporon beigelii) is an emerging fungal pathogen seen particularly in immunologically compromised patients. There are now approximately 100 reported cases of hematogenously disseminated infections with this life-threatening yeast, and no effective antifungal therapy is available. The present case is unusual because the patient did not have neutropenia or evidence of a malignancy.

Antifungal Agents↗
PubMed2001

The evolution of Candida species and fluconazole susceptibility among oral and vaginal isolates recovered from human immunodeficiency virus (HIV)-seropositive and at-risk HIV-seronegative women.

Antifungal agents can effectively treat mucosal candidiasis; however, their use can lead to colonization with less susceptible species and to resistance among normally susceptible strains. Oral and vaginal Candida isolates obtained at 3 points over 2 years from human immunodeficiency virus (HIV)-seropositive and at-risk HIV-seronegative women were identified by species and were evaluated for in vitro fluconazole susceptibility. Prevalence of non-C. albicans strains increased over time, and these strains were more likely among women reporting current antifungal use. Among C. albicans isolates, resistance was rare, with no evidence for progressive reduction in susceptibility over time. Among non-C. albicans isolates, reduced susceptibility occurred frequently and increased with time. HIV-seropositive women were more likely to have non-C. albicans isolates with reduced susceptibility as were women reporting current antifungal use. This evolution and section of mucosa-colonizing Candida species with reduced susceptibility could play a critical early role in the development of antifungal resistance among C. albicans isolates responsible for refractory candidiasis.

AIDS-Related Opportunistic Infections↗
PubMed2001

An empirical model for describing the effects of nitrogen sources on nisin production.

AIMS: A study on the effects of tryptone and yeast extract on nisin production by Lactococcus lactis was carried out using a second order rotatable factorial design. METHODS AND RESULTS: The results show that both ingredients increased nisin production, although a small decrease in nisin levels was noted at high tryptone concentrations. In view of the low vitamin content of tryptone, the amino acids present in both tryptone and yeast extract may be responsible for these observations. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: The observed response suggests that maintaining tryptone concentrations in the centre of the domain and increasing the concentration of yeast extract would be ideal conditions for nisin production. However, when the economic aspects are considered, it appears that low concentrations of yeast extract and reasonably high concentrations of tryptone are optimal.

Anti-Bacterial Agents↗
PubMed2001

Molecular typing by pulsed-field gel electrophoresis of Spanish animal and human Listeria monocytogenes isolates.

A total of 153 strains of Listeria monocytogenes isolated from different sources (72 from sheep, 12 from cattle, 18 from feedstuffs, and 51 from humans) in Spain from 1989 to 2000 were characterized by pulsed-field gel electrophoresis. The strains of L. monocytogenes displayed 55 pulsotypes. The 84 animal, 51 human, and 18 feedstuff strains displayed 31, 29, and 7 different pulsotypes, respectively, indicating a great genetic diversity among the Spanish L. monocytogenes isolates studied. L. monocytogenes isolates from clinical samples and feedstuffs consumed by the diseased animals were analyzed in 21 flocks. In most cases, clinical strains from different animals of the same flock had identical pulsotypes, confirming the existence of a listeriosis outbreak. L. monocytogenes strains with pulsotypes identical to those of clinical strains were isolated from silage, potatoes, and maize stalks. This is the first study wherein potatoes and maize stalks are epidemiologically linked with clinical listeriosis.

Animal Feed↗
PubMed2000

Epidemiology of yeast colonization in the intensive care unit.

In order to investigate the epidemiology of colonization and possible transmission of yeasts among patients and healthcare workers in adult intensive care units (ICUs), 194 patients were followed for a mean of 9 +/- 11 days and 63 healthcare workers were followed for a mean of 132 +/- 52 days. Among the patients, 142 (73%) were colonized by yeast, with Candida albicans being the species most commonly recovered. Most patients (65%) were already colonized with yeast upon admission to the intensive care unit; only 17% became colonized after admission. Persistent colonization occurred in 51 (55%) of 92 patients who had more than three cultures performed; in 75% of them, colonization persisted with the same strain of Candida albicans or Candida glabrata. Bacterial infection in the month preceding entry into the ICU was the only risk factor significantly associated with yeast colonization. Among the healthcare workers, yeasts were isolated from 42 (67%). Candida albicans was most frequently recovered from the oropharynx (19% of occasions), and Candida parapsilosis was most frequently found on hands (8% of occasions). Persistent colonization of the oropharynx occurred in only six healthcare workers, and none had persistence of yeasts on hands. In this non-outbreak setting, 5 (4%) of 123 patient/healthcare worker interactions that were linked epidemiologically yielded the same strain of Candida albicans, providing evidence for possible cross-transmission. No similar link was found between healthcare worker-patient interactions and colonization with Candida glabrata or Candida parapsilosis.

Adult↗
PubMed2000

Candiduria: a randomized, double-blind study of treatment with fluconazole and placebo. The National Institute of Allergy and Infectious Diseases (NIAID) Mycoses Study Group.

Management of candiduria is limited by the lack of information about its natural history and lack of data from controlled studies on the efficacy of treating it with antimycotic agents. We compared fungal eradication rates among 316 consecutive candiduric (asymptomatic or minimally symptomatic) hospitalized patients treated with fluconazole (200 mg) or placebo daily for 14 days. In an intent-to-treat analysis, candiduria cleared by day 14 in 79 (50%) of 159 receiving fluconazole and 46 (29%) of 157 receiving placebo (P<.001), with higher eradication rates among patients completing 14 days of therapy (P<.0001), including 33 (52%) of 64 catheterized and 42 (78%) of 54 noncatheterized patients. Pretreatment serum creatinine levels were inversely related to candiduria eradication. Fluconazole initially produced high eradication rates, but cultures at 2 weeks revealed similar candiduria rates among treated and untreated patients. Oral fluconazole was safe and effective for short-term eradication of candiduria, especially following catheter removal. Long-term eradication rates were disappointing and not associated with clinical benefit.

Aged↗
PubMed2000

Prospective multicenter surveillance study of funguria in hospitalized patients. The National Institute for Allergy and Infectious Diseases (NIAID) Mycoses Study Group.

Although fungal urinary tract infections are an increasing nosocomial problem, the significance of funguria is still not clear. This multicenter prospective surveillance study of 861 patients was undertaken to define the epidemiology, management, and outcomes of funguria. Diabetes mellitus was present in 39% of patients, urinary tract abnormalities in 37.7%, and malignancy in 22.2%; only 10.9% had no underlying illnesses. Concomitant nonfungal infections were present in 85%, 90% had received antimicrobial agents, and 83.2% had urinary tract drainage devices. Candida albicans was found in 51.8% of patients and Candida glabrata in 15.6%. Microbiological and clinical outcomes were documented for 530 (61.6%) of the 861 patients. No specific therapy for funguria was given to 155 patients, and the yeast cleared from the urine of 117 (75.5%) of them. Of the 116 patients who had a catheter removed as the only treatment, the funguria cleared in 41 (35.3%). Antifungal therapy was given to 259 patients, eradicating funguria in 130 (50.2%). The rate of eradication with fluconazole was 45.5%, and with amphotericin B bladder irrigation it was 54.4%. Only 7 patients (1.3%) had documented candidemia. The mortality rate was 19.8%, reflecting the multiple serious underlying illnesses found in these patients with funguria.

Aged↗
PubMed2000

Fungal endophthalmitis diagnosis by detection of Candida albicans DNA in intraocular fluid by use of a species-specific polymerase chain reaction assay.

Candida endophthalmitis is a serious infection secondary to hematogenous dissemination or direct inoculation of the organisms following trauma or eye surgery. The diagnosis is based on the characteristic findings in the infected eye and on culture of vitreous samples. Unfortunately, the yield of vitreous cultures is limited. The use of a Candida albicans species-specific polymerase chain reaction (PCR) assay in the diagnosis of Candida endophthalmitis is reported herein. Four patients with suspected fungal endophthalmitis underwent vitrectomy for diagnostic and therapeutic purposes. In 2 of the 4, vitreous cultures were negative. However, characteristic PCR products were generated in all 4 patient specimens, enabling the rapid diagnosis of Candida endophthalmitis in all 4. Clinical response was observed in all cases. These results demonstrate the utility of PCR-mediated detection of C. albicans in vitreous samples.

Adult↗
PubMed2000

Complete sequence of a beta-lactamase-encoding plasmid in Neisseria meningitidis.

Identical beta-lactamase-encoding (TEM-1) plasmids were found in two different clinical Neisseria meningitidis strains. They were completely sequenced (5,597 bp) and designated pAB6. The plasmid is almost identical to Neisseria gonorrhoeae plasmid pJD5 (5,599 kb) and may have been picked up from a gonococcus in vivo.

Base Sequence↗
PubMed2000

In vitro antifungal susceptibility methods and clinical implications of antifungal resistance.

As new antifungal agents are introduced for the treatment of infections caused by yeasts and filamentous fungi (moulds), it is important that reliable methods are available for the in vitro testing of both new and established agents. The ultimate goal of in vitro testing is the prediction of the clinical outcome of therapy. The use of the M27-A procedures that were developed by the US National Committee for Clinical Laboratory Standards (NCCLS) has led to increased interlaboratory agreement of minimum inhibitory concentrations (MICs) for yeasts and has facilitated the establishment of interpretive breakpoints for fluconazole and itraconazole. The clinical relevance and limitations of these breakpoints are discussed elsewhere. The focus of this paper is to review the advantages and disadvantages of the available methods for antifungal susceptibility testing of yeasts and moulds as well as the clinical implications of in vitro antifungal resistance.

Antifungal Agents↗
PubMed2000

In vitro susceptibilities of Candida and Aspergillus species to Melaleuca alternafolia (tea tree) oil.

Candida species are an important cause of opportunistic infection in the oral cavity of immunocompromised patients, especially HIV infected patients. Melaleuca oil obtained commercially was investigated since it is known to have broad antifungal properties. The in-vitro susceptibilities of Aspergillus and susceptible and resistant Candida species were performed utilizing serial dilutions in microtiter plates with Sabouraud dextrose agar and the commercial preparation of Melaleuca. As a comparator, in vitro susceptibilities to amphotericin B and fluconazole were also determined using the broth microdilution technique. The results demonstrate that Melaleuca inhibited the Candida species. However, the growth of Aspergillus was not inhibited at the concentrations tested. Thus, preparations containing Melaleuca alternafolia may be a useful alternative for superficial candidal infections. In fact, it may be a useful alternative regimen for advanced HIV-positive patients with oropharyngeal candidiasis refractory to fluconazole. However, controlled clinical studies to evaluate its efficacy are still needed.

Journal Article↗
PubMed1999

Short- and long-term effect of a long-acting somatostatin analogue, lanreotide (SR-L) on metastatic gastrinoma.

Medical treatment is the elective therapy for patients with gastrinoma when the tumor is not found at surgery or is unresectable or when there is a metastatic disease. H2-blockers and omeprazol are able to control gastric acid secretion and, in addition, somatostatin analogues decrease gastrin levels. A new long-acting and slow release formulation of a somatostatin analogue (lanreotide, SR-L) has been developed. We treated two patients suffering from gastrinoma, total gastrectomy and hepatic metastases with 30 mg intramuscular injections of SR-L every 15 and 10 days, respectively, for a seven-month period. After the treatment, gastrin levels decreased from 35,494 and 15,086 ng/l to 3,211 and 167 ng/l (92 and 98% below pre-treatment levels) in case 1 and 2 respectively, with a relief of symptoms and no side effects.

Adult↗
PubMed1999

Fungal infections of the urinary tract.

Funguria, fungal urinary tract infections, are most commonly caused by Candida species but may also be caused by Cryptococcus neoformans, Aspergillus species, and the endemic mycoses. Candiduria presents as an increasingly common nosocomial infection, which may involve all anatomic levels of the urinary tract, resulting in a spectrum of disease varying from asymptomatic candiduria to clinical sepsis. Although several successful systemic or local therapeutic options exist for the eradication of candiduria, knowledge of the pathogenesis and natural history of candiduria has lagged. This has resulted in confusion among practitioners as to when antifungal therapy is indicated. Treatment guidelines have recently been formulated and are described herein.

Antifungal Agents↗
PubMed1999

Evaluation of DNA-based typing procedures for strain categorization of Candida spp.

DNA-based procedures have replaced earlier epidemiologic methodologies that relied on nonreproducible and insensitive measurements of phenotypic characteristics to identify a specific strain as the source of infection. The reliability (interlaboratory percent agreement for strain delineation) and sensitivity (recognition of subtle strain-to-strain variation) of similar DNA-based typing systems by different laboratories were evaluated. Ten isolates (five epidemiologic-related and five unrelated strains each) of Candida albicans, C. lusitaniae, C. parapsilosis, C. tropicalis, and Candida (Torulopsis) glabrata were characterized in a blinded fashion by three laboratories. All 50 isolates were subtyped in each laboratory by electrophoretic karyotyping (EK) analysis using contour-clamped homogenous electric field (CHEF) electrophoresis protocols. In addition, two laboratories also performed restriction endonuclease analysis of genomic DNA (REAG) using the restriction endonucleases SfiI and BssHII followed by CHEF electrophoresis separation of resulting fragments. DNA strain identification of the 50 isolates by the three different laboratories using similar CHEF methodologies demonstrated the following species-dependent, interlaboratory reproducibility: C. tropicalis (82%), C. parapsilosis (83%), C. albicans (90%), C. lusitaniae (93%), and C. glabrata (100%). In addition, agreement was higher by the CHEF method (83 to 100%), when compared with the strain types identified by the REAG (60 to 100%) method. Five to seven strains of each Candida species evaluated were detected by the different methodologies used for this study. This study indicates that these procedures are relatively discriminatory and reliable tools to study strain-to-strain variations in epidemiologic evaluations of these yeasts.

Candida↗