ANTIBIOTIC RESISTANCE PATTERNS OF URINARY TRACT INFECTIONS IN A NORTHEASTERN BRAZILIAN CAPITAL

Urinary tract infection is a common problem worldwide. Its clinical characteristics and susceptibility rates of bacteria are important in determining the treatment of choice and its duration. This study assessed the frequency and susceptibility to antimicrobials of uropathogens isolated from community-acquired urinary tract infections in the city of Natal, Rio Grande do Norte State capital, northeastern Brazil, from 2007 to 2010. A total of 1,082 positive samples were evaluated; E. coli was the most prevalent pathogen (60.4%). With respect to the uropathogens susceptibility rates, the resistance of enterobacteria to ciprofloxacin and sulfamethoxazole-trimethoprim was 24.4% and 50.6%, respectively. Susceptibility was over 90% for nitrofurantoin, aminoglycosides and third-generation cephalosporins. High resistance rates of uropathogens to quinolones and sulfamethoxazole-trimethoprim draws attention to the choice of these drugs on empirical treatments, especially in patients with pyelonephritis. Given the increased resistance of community bacteria to antimicrobials, local knowledge of susceptibility rates of uropathogens is essential for therapeutic decision making regarding patients with urinary tract infections.

THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL

Introduction: Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ), but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory. Material and methods: The in vitro activity of PZQ (6.5-0.003 µg/mL) was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni. Results: After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni.

Candida albicans PROTEIN PROFILE CHANGES IN RESPONSE TO THE BUTANOLIC EXTRACT OF Sapindus saponariaL.

Candida albicans is an opportunistic human pathogen that is capable of causing superficial and systemic infections in immunocompromised patients. Extracts of Sapindus saponaria have been used as antimicrobial agents against various organisms. In the present study, we used a combination of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to identify the changes in protein abundance of C. albicans after exposure to the minimal inhibitory concentration (MIC) and sub-minimal inhibitory concentration (sub-MIC) of the butanolic extract (BUTE) of S. saponaria and also to fluconazole. A total of six different proteins with greater than 1.5 fold induction or repression relative to the untreated control cells were identified among the three treatments. In general, proteins/enzymes involved with the glycolysis (GPM1, ENO1, FBA1), amino acid metabolism (ILV5, PDC11) and protein synthesis (ASC1) pathways were detected. In conclusion, our findings reveal antifungal-induced changes in protein abundance of C. albicans. By using the previously identified components of the BUTE of S. saponaria(e.g., saponins and sesquiterpene oligoglycosides), it will be possible to compare the behavior of compounds with unknown mechanisms of action, and this knowledge will help to focus the subsequent biochemical work aimed at defining the effects of these compounds.

The avirulence of the cultivated Y strain of Trypanosoma cruzi: IV. The effect of immunosuppressive agents in mice

Drogas imunossupressoras (Azathioprina e Methotrexato) que se mostraram capazes de agravar infecções experimentais por Trypanosoma cruzi virulento (cepa Y), em camundongos, não conseguiram favorecer o aparecimento de qualquer sinal de infecção em animais vacinados com a cepa avirulenta PF do mesmo tripanosoma. Vinblastine, quando dado 3 dias antes da vacina, não favoreceu parasitemias positivas nem mortalidade significativamente aumentada, mas induziu o aparecimento de hemoculturas positivas. Os tripanosomas dessas culturas foram incapazes de infectar camundongos jovens. Quando o Vinblastine foi usado 15 dias após a vacinação dos animais, todos os testes foram negativos, inclusive as hemoculturas

Trypanosoma cruzi: susceptibility to chemotherapy with benznidazole of clones isolated from the highly resistant Colombian strain

The present investigation was performed to evaluate the susceptibility of seven clones isolated from the highly resistant Colombian strains, prototype of Biodeme Type III. Seven clones previously obtained, showed a phenotypic homogeneity and high similarity with the parental strain. Eight groups of 30 mice were inoculated with one of seven clones or the parental strain; 20 were treated with benznidazole (100mg/kg/day) and 10 were untreated controls. Cure evaluations were done by parasitological and serological tests and PCR. Cure rates varied from 0% (null) to 16.7%. Correlation between positivity of parasitological and serological tests with positive PCR reached 37%. The results demonstrated the high resistance of the clones, suggesting the predominance of a highly resistant principal clone in this strain. The findings apparently indicate that the possibility of cure is minimal for patients infected with this biodeme; a fact that could affect the control of Chagas' disease through treatment of chronically infected people.

Susceptibility of Aedes aegypti (L) to the insect growth regulators diflubenzuron and methoprene in Uberlândia, State of Minas Gerais

Aedes aegypti (L) (Diptera: Culicidae) was reared in several concentrations of diflubenzuron and methoprene under laboratory conditions in Uberlândia, State of Minas Gerais, southeastern Brazil. Characteristics such as LC50 and LC95, the susceptibility of immature stages of different ages to these insect growth regulators and their residual effects were studied. The LC50 and LC95 of diflubenzuron and methoprene were 5.19 and 12.24 ppb; 19.95 and 72.08 ppb, respectively. While diflubenzuron caused great mortality in all larval instars, methoprene was more effective when the mosquito was exposed from the start of the fourth larval instar onwards. Commercial concentrations of these two insect growth regulators close to LC95 presented greater residual activity than did their respective technical formulations. The parameters were compared with those obtained elsewhere. The characteristics investigated here indicate that these insect growth regulators are effective alternatives for controlling the dengue vector in the Uberlândia region.

Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado) seed extracts

The present study had the aim of testing the hexane and methanol extracts of avocado seeds, in order to determine their toxicity towards Artemia salina, evaluate their larvicidal activity towards Aedes aegypti and investigate their in vitro antifungal potential against strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis through the microdilution technique. In toxicity tests on Artemia salina, the hexane and methanol extracts from avocado seeds showed LC50 values of 2.37 and 24.13mg mL-1 respectively. Against Aedes aegypti larvae, the LC50 results obtained were 16.7mg mL-1 for hexane extract and 8.87mg mL-1 for methanol extract from avocado seeds. The extracts tested were also active against all the yeast strains tested in vitro, with differing results such that the minimum inhibitory concentration of the hexane extract ranged from 0.625 to 1.25mg L-¹, from 0.312 to 0.625mg mL-1 and from 0.031 to 0.625mg mL-1, for the strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis, respectively. The minimal inhibitory concentration for the methanol extract ranged from 0.125 to 0.625mg mL-1, from 0.08 to 0.156mg mL-1 and from 0.312 to 0.625mg mL-1, for the strains of Candida spp., Cryptococcus neoformans and Malassezia pachydermatis, respectively.

Evaluation of the histopathological hepatic lesions and opportunistic agents in Brazilian HIV patients

INTRODUCTION: to evaluated the type histopathological hepatic lesions and opportunistic agents in Brazilian HIV-infected patients. METHODS: we examined 52 percutaneous liver biopsies of 50 HIV-infected patients who had at least two of the following conditions: fever of unknown origin, unexplained severe emaciation, hepatomegaly or abnormal liver chemistry. The specimens were cultured for mycobacteria and fungi and stained by standard procedures. RESULTS: reactive patterns, granulomatous hepatitis and chronic active hepatitis were verified in 28 (54%), 11 (21%) and 8 (15%) of the patients respectively. Opportunistic infections were diagnosed in 18 (36%) patients: mycobacteria in 12 (24%), Cryptococcus neoformans in 5 (10%) patients and mycobacteria and yeast was isolated from the same liver fragment in one patient. CONCLUSIONS: mycobacteriosis was the most common opportunistic infection and liver tissue culture is an important method to detect opportunistic agents, even in the absence of histological lesions.

Injuries and envenoming by aquatic animals in fishermen of Coxim and Corumbá municipalities, state of Mato Grosso do Sul, Brazil: identification of the causative agents, clinical aspects and first aid measures

INTRODUCTION: The fishes of continental Brazil have socioeconomic importance due to their potential for sport fishing and commercial and subsistence uses, as seen in the Upper Paraguay River Basin, particularly in the municipalities of the Pantanal region, where it is the second largest economic activity. Injuries caused in professional fishermen are common and poorly studied, as in other regions of the country. METHODS: Data were obtained from questionnaires and interviews with 100 professional fishermen, 50 in each municipality, between December 2008 and October 2009. RESULTS: All the fishermen reported some kind of injury caused by fish stings (78% of injuries) and fish, alligator and snake bites (22%) on the hands (46% of cases) and feet (35% of cases). Most of the patients had mild symptoms. The most severe cases were associated with secondary bacterial infections and required specific treatment and prolonged recovery associated with social and economic losses. CONCLUSIONS: The results of this study indicate that the stressful work conditions, inattention to basic preventive measures and carelessness were factors that contributed to accidents and that the toxicity and ability to inflict mechanical trauma of some aquatic species, plus the ineffective use of first aid and hospital treatment, contributed to the high morbidity and complications in many cases. Data from this study are relevant to the fishing communities of the Pantanal region, since they reveal high rates of accidents, lack of knowledge concerning first aid, initial treatment, injury prevention and lack of medical follow-up of the population.

Nosocomial infections in a Brazilian neonatal intensive care unit: a 4-year surveillance study

INTRODUCTION: Report the incidence of nosocomial infections, causative microorganisms, risk factors associated with and antimicrobial susceptibility pattern in the NICU of the Uberlândia University Hospital. METHODS: Data were collected through the National Healthcare Safety Network surveillance from January 2006 to December 2009. The patients were followed five times/week from their birth to their discharge or death. RESULTS: The study included 1,443 patients, 209 of these developed NIs, totaling 293 NI episodes, principally bloodstream infections (203; 69.3%) and conjunctivitis (52; 17.7%). Device-associated infection rates were as follows: 17.3 primary bloodstream infections per 1,000 central line-days and 3.2 pneumonias per 1000 ventilator-days. The mortality rate in neonates with NI was 11.9%. Mechanical ventilation, total parenteral nutrition, orogastric tube, previous antibiotic therapy, use of CVC and birth weight of 751-1,000g appeared to be associated with a significantly higher risk of NI (p < 0.05). In multiple logistic regression analysis for NI, mechanical ventilation and the use of CVC were independent risk factors (p < 0.05). Coagulase- negative Staphylococcus (CoNS) (36.5%) and Staphylococcus aureus (23.6%) were the most common etiologic agents isolated from cultures. The incidences of oxacillin-resistant CoNS and S. aureus were 81.8% and 25.3%, respectively. CONCLUSIONS: Frequent surveillance was very important to evaluate the association of these well-known risk factors with NIs and causative organisms, assisting in drawing the attention of health care professionals to this potent cause of morbidity.

Aedes aegypti and Aedes albopictus (Diptera: Culicidae): coexistence and susceptibility to temephos, in municipalities with occurrence of dengue and differentiated characteristics of urbanization

INTRODUCTION: The aim of the present study was to verify the coexistence between Aedes aegypti and Aedes albopictus populations in municipalities of the States of Paraná and Santa Catarina with different urbanization profiles where dengue occurs and evaluate their susceptibility to the organophosphate temephos. METHODS: The number of eggs per ovitrap were counted and incubated for hatching to identify the species. Data analysis of the populations was conducted to determine randomness and aggregation, using the variance-to-mean ratio (index of dispersion). Susceptibility to temephos was evaluated by estimation of the resistance ratios RR50 and RR95. Aedes aegypti samples were compared with the population Rockefeller and Aedes albopictus samples were compared with a population from the State of Santa Catarina and with the Rockefeller population. RESULTS: Coexistence between Aedes aegypti and Aedes albopictus and the aggregation of their eggs were observed at all the sites analyzed in the State of Paraná. CONCLUSIONS: All the Aedes aegypti populations from the State of Parana showed alteration in susceptibility status to the organophosphate temephos, revealing incipient resistance. Similarly, all the Aedes albopictus populations (States of Paraná and Santa Catarina) presented survival when exposed to the organophosphate temephos.

Species distribution and in vitro fluconazole susceptibility of clinical Candida isolates in a Brazilian tertiary-care hospital over a 3-year period

INTRODUCTION: In this study, we aimed at identifying Candida isolates obtained from blood, urine, tracheal secretion, and nail/skin lesions from cases attended at the Hospital Universitário de Londrina over a 3-year period and at evaluating fluconazole susceptibilities of the isolates. METHODS: Candida isolates were identified by polymerase chain reaction (PCR) using species-specific forward primers. The in vitro fluconazole susceptibility test was performed according to EUCAST-AFST reference procedure. RESULTS: Isolates were obtained from urine (53.4%), blood cultures (19.2%), tracheal secretion (17.8%), and nail/skin lesions (9.6%). When urine samples were considered, prevalence was similar in women (45.5%) and in men (54.5%) and was high in the age group >61 years than that in younger ones. For blood samples, prevalence was high in neonates (35%) and advanced ages (22.5%). For nail and skin samples, prevalence was higher in women (71.4%) than in men (28.6%). Candida albicans was the most frequently isolated in the hospital, but Candida species other than C. albicans accounted for 64% of isolates, including predominantly Candida tropicalis (33.2%) and Candida parapsilosis (19.2%). The trend for non-albicans Candida as the predominant species was noted from all clinical specimens, except from urine samples. All Candida isolates were considered susceptible in vitro to fluconazole with the exception of isolates belonging to the intrinsically less-susceptible species C. glabrata. CONCLUSIONS: Non-albicans Candida species were more frequently isolated in the hospital. Fluconazole resistance was a rare finding in our study.

Methicillin-resistant Staphylococcus aureus bloodstream infection: risk factors and clinical outcome in non-intensive-care units

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.

Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from patients attending a public referral center for sexually transmitted diseases in Belo Horizonte, State of Minas Gerais, Brazil

Introduction The aim of this study was to determine the antimicrobial susceptibility of Neisseria gonorrhoeae isolates obtained from patients attending a public referral center for sexually transmitted diseases and specialized care services (STD/SCS) in Belo Horizonte, Brazil. Methods Between March 2011 and February 2012, 201 specimens of Neisseria gonorrhoeae were consecutively obtained from men with symptoms of urethritis and women with symptons of cervicitis or were obtained during their initial consultation. The strains were tested using the disk diffusion method, and the minimum inhibitory concentrations of azithromycin, cefixime, ceftriaxone, ciprofloxacin, chloramphenicol, penicillin, tetracycline and spectinomycin were determined using the E-test. Results The specimens were 100% sensitive to cefixime, ceftriaxone and spectinomycin and exhibited resistances of 4.5% (9/201), 21.4% (43/201), 11.9% (24/201), 22.4% (45/201) and 32.3% (65/201) to azithromycin, ciprofloxacin, chloramphenicol, penicillin and tetracycline, respectively. Intermediate sensitivities of 17.9% (36/201), 4% (8/201), 16.9% (34/201), 71.1% (143/201) and 22.9% (46/201) were observed for azithromycin, ciprofloxacin, chloramphenicol, penicillin and tetracycline, respectively. The specimens had plasmid-mediated resistance to penicillin PPNG 14.5% (29/201) and tetracycline TRNG 11.5% (23/201). Conclusions The high percentage of detected resistance to penicillin, tetracycline, chloramphenicol and ciprofloxacin indicates that these antibiotics are not appropriate for gonorrhea treatment at the Health Clinic and possibly in Belo Horizonte. The resistance and intermediate sensitivity of these isolates indicates that caution is recommended in the use of azithromycin and emphasizes the need to establish mechanisms for the surveillance of antimicrobial resistance for the effective control of gonorrhea.

Contributions of culture and antimicrobial susceptibility tests to the retreatment of patients with pulmonary tuberculosis

Introduction This study evaluated the efficacy of retreatment of pulmonary tuberculosis (TB) with regard to treatment outcomes and antimicrobial susceptibility testing (ST) profiles. Methods This retrospective cohort study analyzed 144 patients treated at a referral hospital in Brazil. All of them had undergone prior treatment, were smear-positive for TB and received a standardized retreatment regimen. Fisher's 2-tailed exact test and the χ2 test were used; RRs and 95% CIs were calculated using univariate and multivariate binary logistic regression. Results The patients were cured in 84 (58.3%) cases. Failure was associated with relapsed treatment and abandonment (n=34). Culture tests were obtained for 103 (71.5%) cases; 70 (48.6%) had positive results. ST results were available for 67 (46.5%) cases; the prevalence of acquired resistance was 53.7%. There were no significant differences between those who achieved or not therapeutic success (p=0.988), despite being sensitive or resistant to 1 or more drugs. Rifampicin resistance was independently associated with therapeutic failure (OR: 4.4, 95% CI:1.12-17.37, p=0.034). For those cases in which cultures were unavailable, a 2nd model without this information was built. In this, return after abandonment was significantly associated with retreatment failure (OR: 3.59, 95% CI:1.17-11.06, p=0.026). Conclusions In this cohort, the general resistance profile appeared to have no influence on treatment outcome, except in cases of rifampicin resistance. The form of reentry was another independent predictor of failure. The use of bacterial culture identification and ST in TB management must be re-evaluated. The recommendations for different susceptibility profiles must also be improved.