Ampicillin/sulbactam compared with polymyxins for the treatment of infections caused by carbapenem-resistant Acinetobacter spp.

Background: There has been an increase in worldwide infections caused by carbapenem-resistant Acinetobacter. This poses a therapeutic challenge as few treatment options are available. Objectives: The aim of this study was to evaluate the efficacy and safety of polymyxins and ampicillin/sulbactam for treating infections caused by carbapenem-resistant Acinetobacter spp. and to evaluate prognostic factors. Methods: This was a retrospective review of patients from two teaching hospitals who had nosocomial infections caused by carbapenem-resistant Acinetobacter spp. from 1996 to 2004. Diagnosis of infection was based on CDC criteria plus the isolation of Acinetobacter from a usually sterile site or from bronchoalveolar lavage. Urinary tract infections were not included. Data on demographic and clinical features and treatment were collected from medical records. Prognostic factors associated with two outcomes (mortality during treatment and in-hospital mortality) were evaluated. Results: Eighty-two patients received polymyxins and 85 were treated with ampicillin/sulbactam. Multiple logistic regression analysis revealed that independent predictors of mortality during treatment were treatment with polymyxins, higher Acute Physiological and Chronic Health Evaluation II (APACHE II) score, septic shock, delay in starting treatment and renal failure. On multivariate analysis, prognostic factors for in-hospital mortality were older age, septic shock and higher APACHE II score. Conclusions: This is the first study comparing current therapeutic options for infections due to carbapenem-resistant Acinetobacter. The most important finding of the present study is that ampicillin/sulbactam appears to be more efficacious than polymyxins, which was an independent factor associated with mortality during treatment.

Rhodotorula spp. isolated from blood cultures: clinical and microbiological aspects

The emergence of less common fungal pathogens has been increasingly reported in the last decade. We describe 25 cases of Rhodotorula spp. isolated from blood cultures at a large Brazilian tertiary teaching hospital from 1996-2004. We also investigated the in vitro activity of four antifungal drugs, using a standardized method. The median age of patients was 43 years. The majority of patients (88%) had a central venous catheter (CVC) and 10 (40%) were recipients of a bone marrow transplant. The episode was classified as a bloodstream infection (BSI) in 80% of the patients. Amphotericin B deoxycholate was the most common antifungal used and CVC was removed in 89.5% of the patients. Death occurred in four patients (17.4%), all classified as BSI. All strains were identified as R. mucilaginosa by conventional methods. Misidentification of the species was observed in 20% and 5% of the strains with the Vitek Yeast Biochemical Card and API 20C AUX systems, respectively. Amphotericin B demonstrated good in vitro activity (MIC(50/90), 0.5 mu g/ml) and the MICs for fluconazole were high for all strains (MIC(50/90), 64 mu g/ml).

Bacterial and fungal pneumonias after lung transplantation

Objective. The aim of this study was to evaluate the epidemiology of bacterial and fungal pneumonia in lung transplant (LT) recipients and to assess donor-to-host transmission of these microorganisms. Materials and Methods. We retrospectively studied all positive cultures from bronchoalveolar lavage (BAL) of 49 lung transplant recipients and their donors from August 2003 to April 2007. Results. There were 108 episodes of pneumonia during a medium follow-up of 412 days (range, 1-1328 days). The most frequent microorganisms were: Pseudomonas aeruginosa (n = 36; 33.3%), Staphylococcus aureus (n = 29; 26.8%), and Aspergillus spp. (n = 18; 16%). Other fungal infections were due to Fusarium spp., Cryptococcus neoformans, and Paracoccidioides brasiliensis. Of the 31 donors with positive BAL, 15 had S. aureus. There were 21 pretransplant colonized recipients (43%) and 16 of them had suppurative underlying lung disease. P. aeruginosa was the most frequent colonizing organism (59% of pretransplant positive cultures). There were 11 episodes of bacteremia and lungs were the source in 5 cases. Sixteen deaths occurred and 6 (37.5%) were due to infection. Statistical analyses showed association between pretransplant colonizing microorganisms from suppurative lung disease patients and pneumonias after lung transplantation (RR = 4.76; P = .04; 95% CI = 1.02-22.10). No other analyzed factor was significant. Conclusions. Bacterial and fungal infections are frequent and contribute to higher mortality in lung transplant recipients. P. aeruginosa is the most frequent agent of respiratory infections. This study did not observe any impact of donor lung organisms on pneumonia after lung transplantation. Nevertheless, we demonstrated an association between pretransplant colonizing microorganisms and early pneumonias in suppurative lung transplant recipients.

Genotype and mating type distribution within clinical Cryptococcus neoformans and Cryptococcus gattii isolates from patients with cryptococcal meningitis in Uberaba, Minas Gerais, Brazil

We molecularly characterized 81 cryptococcal isolates recovered from cerebrospinal fluid samples of 77 patients diagnosed between 1998 and 2007 as having cryptococcal meningitis in Uberaba Minas Gerais, Brazil. Fifty-seven (74%) were male with a mean age 35.6 years. Seventy-two (88.9%) of the isolates were from 68 AIDS patients and cryptococcosis was the first AIDS-defining condition in 38 (55.9%) patients. Cryptococcosis and AIDS were simultaneously diagnosed in 25 (65.8%) of these 38 patients. Genotypes were characterized through the use of URA5 restriction fragment length polymorphisms analysis, the genetic variability was determined using PCR-fingerprinting with the minisatellite-specific primer M13, and the mating type and serotypes were established by PCR. Seventy-six of the 81 isolates were Cryptococcus neoformans (93.8%), while the remaining five were C. gattii (6.1%), but all were mating type a. C. neoformans isolates were genotype VNI (serotype A), while C. gattii isolates were VGII. Four of the latter isolates were identical, but only two were from AIDS patients. Six of the nine isolates from non-AIDS patients were VNI. PCR fingerprints of the isolates from two of the three AIDS patients with clinical relapse were 100% identical. The predominance of VNI and mating type a is in accordance with data from other parts of the world. The occurrence of VGII in Minas Gerais indicates a geographical expansion within Brazil.

Pore Formation Triggered by Legionella spp. Is an Nlrc4 Inflammasome-Dependent Host Cell Response That Precedes Pyroptosis

Legionella pneumophila, the etiological agent of Legionnaires disease, is known to trigger pore formation in bone marrow-derived macrophages (BMMs) by mechanisms dependent on the type IVB secretion system known as Dot/Icm. Here, we used several mutants of L. pneumophila in combination with knockout mice to assess the host and bacterial factors involved in pore formation in BMMs. We found that regardless of Dot/Icm activity, pore formation does not occur in BMMs deficient in caspase-1 and Nlrc4/Ipaf. Pore formation was temporally associated with interleukin-1 beta secretion and preceded host cell lysis and pyroptosis. Pore-forming ability was dependent on bacterial Dot/Icm but independent of several effector proteins, multiplication, and de novo protein synthesis. Flagellin, which is known to trigger the Nlrc4 inflammasome, was required for pore formation as flaA mutant bacteria failed to induce cell permeabilization. Accordingly, transfection of purified flagellin was sufficient to trigger pore formation independent of infection. By using 11 different Legionella species, we found robust pore formation in response to L. micdadei, L. bozemanii, L. gratiana, L. jordanis, and L. rubrilucens, and this trait correlated with flagellin expression by these species. Together, the results suggest that pore formation is neither L. pneumophila specific nor the result of membrane damage induced by Dot/Icm activity; instead, it is a highly coordinated host cell response dependent on host Nlrc4 and caspase-1 and on bacterial flagellin and type IV secretion system.

Detection of Leptospira spp. in semen and vaginal fluids of goats and sheep by polymerase chain reaction

Thirteen goat herds and seven sheep flocks in the state of Rio de Janeiro, Brazil were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity, 19 goats (16 females and three bucks) and 40 sheep (26 ewes and 14 rams) that were seropositive (specific anti-Leptospira titres >= 400, based on a microscopic agglutination test), were selected for more detailed studies. From those animals, samples of vaginal fluids or semen were collected for bacteriological and molecular assays. For both species of animals, the most prevalent reactions were to serovars Hardjo, Shermani, and Grippotyphosa. Although leptospires were detected by darkfield microscopy in three vaginal fluid samples (from two goats and one ewe), pure isolates were not obtained by bacteriological culture of vaginal fluids or semen. However, seven vaginal fluid samples (from four goats and three ewes) and six semen samples (all from rams) were positive on polymerase chain reaction (PCR). Based on these findings, in addition to analogous findings in cattle, we inferred that there is potential for venereal transmission of leptospirosis in small ruminants. (c) 2008 Elsevier Inc. All rights reserved.

Phenotypic and molecular characterization of recent and archived Erysipelothrix spp. isolated from Brazilian swine

One hundred fifty-one Erysipelothrix spp. isolates from Brazilian swine were characterized by serotyping, determination of antimicrobial susceptibility, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE). Among all isolates, 139 were classified in 18 different serotypes and serotype 2b was the most frequent. The susceptibility profiles of the isolates were very similar among each other, which did not permit subtyping Erysipelothrix spp. isolates by the antimicrobial susceptibility testing. Despite the fact that AFLP and PFGE provided the same discriminatory index (0.98), PFGE was more discriminatory than AFLP, given the types of groups it generates. Regardless the technique employed (AFLP or PFGE), no discrimination between recent and historical isolates was established, neither a fixed epidemiologic pattern for their grouping was observed. Nevertheless, AFLP could be an interesting alternative for discriminating the Erysipelothrix species, while PFGE could be an indication for discerning this bacterium according to the serotypes. (C) 2011 Elsevier Inc. All rights reserved.

Genotyping of Brazilian Erysipelothrix spp. strains by amplified fragment length polymorphism

One hundred and fifty-one Erysipelothrix spp. isolates from diseased and carrier swine from Brazil were identified by PCR, submitted to serotyping and analyzed by amplified fragment length polymorphism with a single enzyme (AFLP). Reference strains from Australia and the United Kingdom were also examined. The 151 strains were classified into 18 different serotypes (1a, 1b, 2a, 2b, 4, 5, 6, 7, 8, 10, 11, 12, 15, 17, 19, 21, 24 and 25), being serotype 2b the most frequent (39.7%). By associating serotyping and PCR results, it was possible to identify 146 strains as E. rhusiopathiae and five strains as E. tonsillarum. Despite the fact that for this genus AFLP did not cluster all isolates according to serotype, origin, disease or isolation data, the execution of the technique was easy and fast, demonstrating high discriminatory power. The results produced by the AFLP analysis of Erysipelothrix spp. could also support its use as a discriminatory tool for E. rhusiopathiae and E. tonsillarum species. (C) 2010 Elsevier B.V. All rights reserved.

Detection of Bartonella spp. in neotropical felids and evaluation of risk factors and hematological abnormalities associated with infection

Although antibodies to Bartonella henselae have been described in all neotropical felid species, DNA has been detected in only one species, Leopard us wiedii. The aim of this study was to determine whether DNA of Bartonella spp. could be detected in blood of other captive neotropical felids and evaluate risk factors and hematological findings associated with infection. Blood samples were collected from 57 small felids, including 1 Leopard us geoffroyi, 17 L wiedii, 22 Leopardus tigrinus, 14 Leopardus pardalis, and 3 Puma yagouaroundi; 10 blood samples from Panthera onca were retrieved from blood banks. Complete blood counts were performed on blood samples from small felids, while all samples were evaluated by PCR. DNA extraction was confirmed by amplification of the cat GAPDH gene. Bartonella spp. were assessed by amplifying a fragment of their 16S-23S rRNA intergenic spacer region; PCR products were purified and sequenced. For the small neotropical felids, risk factors [origin (wild-caught or zoo-born), gender, felid species, and flea exposure) were evaluated using exact multiple logistic regression. Hematological findings (anemia, polycythemia/hyperproteinemia, leukocytosis and leukopenia) were tested for association with infection using Fisher`s exact test. The 635 bp product amplified from 10 samples (10/67 = 14.92%) was identified as B. henselae by sequencing. Small neotropical felid males were more likely to be positive than females (95% CI = 0.00-0.451, p = 0.0028), however other analyzed variables were not considered risk factors (p > 0.05). Hematological abnormalities were not associated with infection (p > 0.05). This is the first report documenting B. henselae detection by PCR in several species of neotropical felids. (C) 2009 Elsevier B.V. All rights reserved.

Liver iron overloading in captive muriquis (Brachyteles spp.)

Background Iron accumulation was investigated qualitatively and quantitatively in the liver of 15 captive Brachyteles spp. Methods Hepatic hemosiderosis index (HHI) was determined as the area percentage of the liver parenchyma occupied by hemosiderin and ferritin deposits, through computerized histomorphometric analysis of Prussian blue-stained histologic sections. Results All studied animals presented liver hemosiderosis, and HHI ranged from 0.2% to 41.7%. There were no significant differences in HHI between muriqui species or genders, and no correlations were detected among HHI and age, time in captivity or body mass. Iron deposits were accompanied by other hepatic disorders. Conclusions This is the first study addressing the occurrence and consequences of iron overloading in the liver of muriquis. We propose that hemosiderosis may act as a contribute factor for the development of hepatic injuries. Further studies are advised to clarify the role of diet in the pathogenesis of hemosiderosis in these atelids.