Effect of promethazine on biofilms of gram-positive cocci associated with infectious endocarditis.

This study evaluated the antimicrobial activity of promethazine against Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus mutans and its effect on the antimicrobial susceptibility of biofilms grown in vitro and ex vivo on porcine heart valves. Promethazine was evaluated alone and in combination with vancomycin and oxacillin against Staphylococcus spp. and vancomycin and ceftriaxone against S. mutans in planktonic form and biofilms grown in vitro and ex vivo. Promethazine minimum inhibitory concentration range was 24.4-95.31 µg/mL and minimum biofilm eradication concentration range was 781.25-3.125 µg/mL. Promethazine interacted synergistically with vancomycin, oxacillin and ceftriaxone against biofilms in vitro. Promethazine alone reduced (p < 0.05) the CFU-counts of biofilms grown on heart valves for Staphylococcus spp., but not for S. mutans, and increased (p < 0.05) the activity of vancomycin, oxacillin and ceftriaxone against biofilms of Gram-positive cocci grown ex vivo. These findings bring perspectives for repurposing promethazine as adjuvant in the treatment of infective endocarditis.

Virulence factors of Gram-negative bacteria from free-ranging Amazon river dolphins (Inia geoffrensis).

Freshwater cetaceans play a significant role as sentinel animals, providing important data on animal species and aquatic ecosystem health. They also may serve as potential reservoirs of emerging pathogens and host virulence genes in their microbiota. In this study, we evaluated virulence factors produced by Gram-negative bacteria recovered from individuals belonging to two populations of free-ranging Amazon river dolphins (Inia geoffrensis). A total of 132 isolates recovered from the oral cavity, blowhole, genital opening and rectum of 21 river dolphins, 13 from Negro River and 8 from Tapajós River, Brazil, were evaluated for the production of virulence factors, such as biofilms and exoproducts (proteases, hemolysins and siderophores), in planktonic and biofilm forms. In planktonic form, 81.1% (107/132) of the tested bacteria of free-ranging Amazon river dolphins were able to produce virulence factors, with 44/132 (33.4%), 65/132 (49,2%) and 54/132 (40,9%) positive for protease, hemolysin and siderophore production, respectively. Overall, 57/132 (43.2%) of the isolates produced biofilms and, under this form of growth, 66/132 (50%), 88/132 (66.7%) and 80/132 (60.6%) of the isolates were positive for protease, hemolysin and siderophore production. In general, the isolates showed a higher release of exoproducts in biofilm than in planktonic form (P < 0.001). The present findings show that Amazon river dolphins harbor potentially pathogenic bacteria in their microbiota, highlighting the importance of monitoring the micro-organisms from wild animals, as they may emerge as pathogens for humans and other animals.

One Health Implications of Antimicrobial Resistance in Bacteria from Amazon River Dolphins.

Studies on the microbiota of freshwater cetaceans are scarce and may provide important data on animal and environmental health. This study aimed to evaluate the antimicrobial susceptibility of Gram-negative bacteria recovered from two populations of free-ranging Amazon river dolphins (Inia geoffrensis). Twenty-one animals were captured and released, 13 from Negro River and 8 from Tapajós River, Brazil. Swab samples were obtained from the oral cavity, blowhole, genital opening and rectum and were cultured on MacConkey agar. Isolates were biochemically identified, and antimicrobial susceptibility was assessed by disk diffusion method. Overall, 132 isolates were recovered, of which 71 were recovered from animals from Negro River and 61 from Tapajós River. The most commonly recovered bacterial species were Enterobacter cloacae, Morganella morganii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Overall, 51.6% (63/122) of the isolates were not-susceptible (intermediate resistance and resistance), of which 28/122 (22.9%) were resistant to at least one antimicrobial. Cephalothin, cefuroxime and cefepime were the drugs to which more resistant and intermediate results were observed (P < 0.001). The results indicate that free-ranging Amazon river dolphins host resistant bacteria, contributing for their maintenance in the environment. This study highlights the importance of the One Health approach to monitor the emergence of antimicrobial resistance. Summary Gram-negative bacteria recovered from 21 free-ranging Amazon river dolphins (Inia geoffrensis) from the Negro River and the Tapajós River populations were evaluated for their antimicrobial susceptibility. Overall, 51.6% (63/122) of the isolates were not-susceptible (intermediate resistance and resistance), of which 28/122 (22.9%) were resistant to at least one antimicrobial. Cephalothin, cefuroxime and cefepime were the drugs to which more resistant and intermediate results were observed. Thus, free-ranging Amazon river dolphins, never treated with antimicrobials, host resistant bacteria, contributing for their maintenance in the environment and highlighting the importance of the One Health approach to monitor the emergence of antimicrobial resistance.

Mini-review: from in vitro to ex vivo studies: an overview of alternative methods for the study of medical biofilms.

Microbial biofilms are a natural adaptation of microorganisms, typically composed of multiple microbial species, exhibiting complex community organization and cooperation. Biofilm dynamics and their complex architecture are challenging for basic analyses, including the number of viable cells, biomass accumulation, biofilm morphology, among others. The methods used to study biofilms range from in vitro techniques to complex in vivo models. However, animal welfare has become a major concern, not only in society, but also in the academic and scientific field. Thus, the pursuit for alternatives to in vivo biofilm analyses presenting characteristics that mimic in vivo conditions has become essential. In this context, the present review proposes to provide an overview of strategies to study biofilms of medical interest, with emphasis on alternatives that approximate experimental conditions to host-associated environments, such as the use of medical devices as substrata for biofilm formation, microcosm and ex vivo models.

Clinical and environmental isolates of Burkholderia pseudomallei from Brazil: Genotyping and detection of virulence gene.

OBJECTIVE: To evaluate the genetic diversity of clinical and environmental isolates of Burkholderia pseudomallei (B. pseudomallei) recovered in Ceará, Brazil, and screen these isolates for the presence of type three secretion system virulence gene. METHODS: Nineteen B. pseudomallei isolates (9 from clinical cases and 10 from soils) were analyzed. Random amplified polymorphic DNA was performed with primers OPQ-2, OPQ-4 and OPQ-16 to evaluate the genetic diversity, and type three secretion system gene was detected through polymerase chain reaction. RESULTS: Random amplified polymorphic DNA showed a genetic relatedness of approximately 50% among the tested B. pseudomallei isolates, which were grouped into two clades, of which the biggest ones comprised 18/19 isolates for primer OPQ-2, and 17/19 isolates for primer OPQ-16. Primer OPQ-4 grouped the isolates into three clades comprising 1/19, 3/19 and 15/19 isolates. Additionally, type three secretion system gene was detected in all tested isolates. CONCLUSIONS: This is an effort to type B. pseudomallei strains from Ceará, which is important for better understanding this pathogen, contributing for the epidemiological surveillance of melioidosis in this endemic region.

Aspectos clínicos e epidemiológicos de pneumonias infantis associadas aos quatro tipos de vírus para influenza em Fortaleza-CE

As pneumonias são problemas de saúde publica mundial, especialmente em crianças menores que cinco anos de idade. Os vírus para influenza (VPI-1, 2 e 3) são agentes frequentes de pneumonia, pouco se conhecendo sobre a participação do VPI-4devido a dificuldades do seu isolamento em cultura de células, a ausência de antígenos específicos para este vírus nos painéis de rotina de detecção dos vírus respiratórios,além de serem relacionados apenas a casos de infecções respiratórias leves. O objetivo do presente estudo é descrever o perfil epidemiológico e clínico das pneumonias causadas pelos quatro tipos de VPI na população de estudo, no período de janeiro de2013 a dezembro de 2014. Para tanto, aspirados nas ofaríngeos de 542 crianças de até cinco anos atendidas no Hospital Infantil Albert Sabin (HIAS), que receberam o diagnóstico de pneumonia, foram submetidos à RT-PCR para a detecção dos VPI-1, 2 e3 e 4. Estas amostras tinham sido analisadas anteriormente por imunofluores cência indireta para vírus sincicial respiratório (VSR), influenza (A e B), adenovírus e VPI (1,2 e 3). Os VPI foram detectados em 165 casos, seguido de VSR (136), adenovírus (34) e influenza (30). As características clínicas e epidemiológicas de pneumonias pelos VPI foram analisadas em 104 amostras que apresentaram infecção isolada por um dos quatro tipos de VPI. Os VPI mais frequentemente detectados, em ordem decrescente, foram os tipos VPI-3 (64,42%), VPI-4 (19,23%), VPI-1(14,42%) e VPI-2 (1,92%). O VPI-4 foi omais associado a co-infecções. O VPI-4 foi o único VPI cuja circulação esteve associada à estação chuvosa dos dois anos de estudo (p<0,0001). O VPI-3 e o VPI-1apresentaram pico de circulação associado à estação seca. Os VPI são agentes frequentes de pneumonias em crianças menores que cinco anos na cidade de Fortaleza.

Pneumonia are public health problems world wide, especially in childrenyounger than five years old. Human parainfluenza virus (HPIV-1, 2 and 3) are commonagents of pneumonia, little was know about the involvement of HPIV-4 due todifficulties of isolation in cell culture, the absence of antigens specific for this virus inpanels routine detection of respiratory viruses, and are associated only with cases ofmild respiratory infections. The aim of this study is to describe the clinical andepidemiological profile of pneumonia caused by four types of HPIV in the studypopulation, from January 2013 to December 2014. To this end, nasopharyngeal aspiratesof 542 children under five treated at Hospital Infantil Albert Sabin (HIAS), who werediagnosed with pneumonia, were subjected to RT-PCR for the detection of HPIV-1, 2, 3and 4. These samples had been previously analyzed by indirect immunofluorescence forrespiratory syncytial virus (RSV), influenza (A and B), adenovirus, and HPIV (1, 2 and3). The HPIV were detected in 165 cases, followed by RSV (136), adenovirus (34) andinfluenza (30). Clinical and epidemiological characteristics of pneumonia by HPIVwere analyzed in 104 samples with isolated infection with one of four types of HPIV.The HPIV most frequently detected, in descending order, were the HPIV-3 types(64.42%), HPIV-4 (19.23%), HPIV-1 (14.42%) and HPIV-2 (1.92 %). The HPIV-4 wasthe most associated with co-infection. The HPIV-4 was the only HPIV whosecirculation was associated with the rainy season of two years of study (p <0.0001). The HPIV-3 and HPIV-1 had a circulation peak associated with the dry season. The HPIVare frequent agents of pneumonia in children younger than five years in the city of Fortaleza.