Ultrastructural study of morphological changes in Schistosoma mansoni after in vitro exposure to the monoterpene rotundifolone

ABSTRACT INTRODUCTION: Schistosomiasis, a parasitic disease caused by trematode flatworms of the genus Schistosoma, affects more than 200 million people worldwide, and its control is dependent on a single drug, praziquantel. Here, we report the in vitro effect of rotundifolone, a monoterpene isolated from Mentha x villosa (Lamiaceae), on Schistosoma mansoni adult worms. METHODS: The in vitro effect of rotundifolone on adult Schistosoma mansoni was evaluated by analysis of behavior and mortality and through a scanning electron microscopic analysis of ultrastructural changes in the tegument of the worms. RESULTS: At concentrations of 3.54 and 7.09μg/mL-1 rotundifolone, no worm mortality was observed at any of the sampling intervals. A minor reduction in movement of the tail, suckers, and gynecophoral canal membrane was observed after 96 h of exposure to 7.09μg/mL-1 rotundifolone. At 70.96μg/mL-1, a lack of movement was observed from 72h onwards and all worms were deemed dead; similar effects were observed at 48h with 177.4μg/mL-1, and at 24h with 354.8μg/mL-1 and 700.96μg/mL-1. Rotundifolone also caused death of all parasites and separation of coupled pairs into individual males and females after 24h at 354.8μg/mL-1. CONCLUSIONS: The main changes in the tegument induced by the different ROT treatments were: after 24h incubation, bubble lesions spread over the entire body and loss of tubercles occurred in some regions of the ventral region.

ULTRASTRUCTURAL CHANGES IN Schistosoma mansoni MALE WORMS AFTER in vitro INCUBATION WITH THE ESSENTIAL OIL OF Mentha x villosa Huds

Introduction: The essential oil Mentha x villosa (MVEO) has a wide range of actions, including antibacterial, antifungal, antiprotozoal and schistosomicidal actions. The present study aimed to investigate the ultrastructural changes of MVEO on the tegument of adult Schistosoma mansoni. Materials and Methods: Different concentrations of MVEO were tested on S. mansoni adult worms in vitro. Ultrastructural changes on the tegument of these adult worms were evaluated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: The MVEO caused the death of all worms at 500 μg mL-1 after 24 h. After 24h of 500 μg mL-1 MVEO treatment, bubble lesions were observed over the entire body of worms and they presented loss of tubercles in some regions of the ventral portion. In the evaluation by TEM, S. mansoni adult worms treated with MVEO, 500 μg mL-1, presented changes in the tegument and vacuoles in the syncytial matrix region. Glycogen granules close to the muscle fibers were visible. Conclusion: The ability of MVEO to cause extensive ultrastructural damage to S. mansoni adult worms correlates with its schistosomicidal effects and confirms earlier findings with S. mansoni.

blaCTX-M-2 and blaCTX-M-28 extended-spectrum â-lactamase genes and class 1 integrons in clinical isolates of Klebsiella pneumoniae from Brazil

Twenty-eight Klebsiella pneumoniae clinical isolates that exhibited an extended-spectrum cephalosporin-resistance profile from a city in the Northeast of Brazil were analysed by PCR and DNA sequencing in order to determine the occurrence of blaCTX-M genes and class 1 integrons. We determined the occurrence of the blaCTX-M-2 gene in six K. pneumoniae isolates and describe the first detection of the blaCTX-M-28 gene in South America. Seven isolates carried class 1 integrons. Partial sequencing analysis of the 5'-3'CS variable region in the class 1 integrons of three isolates revealed the presence of aadA1, blaOXA-2 and dfr22 gene cassettes.

Análise epidemiológica de isolados clínicos de Pseudomonas aeruginosa provenientes de hospital universitário / Epidemiologic analysis of clinical isolates of Pseudomonas aeruginosa from an university hospital

OBJETIVOS: A Pseudomonas aeruginosa é um patógeno oportunista que tem se destacado quanto à prevalência em casos de infecções hospitalares. Sua ampla resistência aos diversos grupos de antimicrobianos garante a este microrganismo um papel de destaque entre as bactérias mais prevalentes associadas à infecção nosocomial. O objetivo deste estudo foi realizar um levantamento epidemiológico da P. aeruginosa, bem como do seu perfil de susceptibilidade aos antimicrobianos no Hospital das Clínicas da Universidade Federal de Pernambuco. MÉTODOS: Foi realizado um estudo retrospectivo baseado no livro de registro de secreções diversas do laboratório de bacteriologia do Hospital das Clínicas no período compreendido entre janeiro a junho de 2008. Entre os registros, identificamos aqueles que foram positivos para a P. aeruginosa, analisando sua origem e perfil de susceptibilidade aos antimicrobianos utilizados na rotina daquele laboratório. RESULTADOS: As bactérias mais freqüentes, isoladas das secreções diversas, foram P. aeruginosa (26 por cento) e S. aureus (25 por cento). Quanto à origem, a P. aeruginosa foi isolada principalmente de infecções respiratórias, pois 33 por cento das amostras positivas para esta bactéria foram provinientes de secreções traqueais e 21 por cento nasais. Os antimicrobianos mais eficazes contra a P. aeruginosa foram: amicacina, imipenem, meropenem e aztreonam. CONCLUSÕES: Estes resultados mostram uma alta prevalência de P. aeruginosa, no Hospital das Clínicas da Universidade Federal de Pernambuco. Apesar de apresentar grande resistência a antimicrobianos mais antigos como as cefalosporinas de primeira e segunda geração, assim como cloranfenicol, em geral, este patógeno demonstrou boa sensibilidade às drogas utilizadas na rotina deste hospital.

OBJECTIVES: Pseudomonas aeruginosa is an increasingly prevalent opportunistic pathogen in hospital infection cases. Its high resistance rates to many antimicrobials has given this microorganism a relevant role among other highly prevalent bacteria involved in nosocomial infections. This study aimed to analyze epidemiologic characteristics of P. aeruginosa and to evaluate its susceptibility to antimicrobial agents at Hospital das Clínicas of the Universidade Federal de Pernambuco METHODS: A retrospective study was performed based on the registry book of miscellaneous secretions from the bacteriology laboratory of the Hospital das Clínicas involving the period between January and June 2008. Among the secretions registered, were identified the positives samples for P. aeruginosa, whose origin was analyzed, as well as its susceptibility profile to routinely used in our laboratory antimicrobials. RESULTS: The bacteria most frequently isolated from miscellaneous secretions bacteria were P. aeruginosa (26 percent) and S. aureus (25 percent). P. aeruginosa was mainly isolated from respiratory infections, with 33 percent of positive samples for this organism from tracheal secretions and 21 percent from nasal. The most effective antimicrobials against P. aeruginosa were: amikacin, imipenem, meropenem and aztreonam. CONCLUSIONS: These results show a high prevalence of P. aeruginosa in the Hospital das Clínicas of the Universidade Federal de Pernambuco. Despite featuring high resistance rates to older antimicrobials, as cephalosporins first and second generations and chloramphenicol, this pathogen showed good susceptibility to agents routinely used in this hospital.