Evaluation of three alum-precipitated Aeromonas hydrophila vaccines administered to Labeo rohita, Cirrhinus mrigala and Ctenopharyngodon idella: immunokinetics, immersion challenge and histopathology / Avaliação de três vacinas de Aeromonas hydrophila precipitadas com alúmen administradas a Labeo rohita, Cirrhinus mrigala e Ctenopharyngodon idella: imunocinética, desafio de imersão e histopatologia

Abstract Aeromonas hydrophila is a cause of infectious disease outbreaks in carp species cultured in South Asian countries including Pakistan. This bacterium has gained resistance to a wide range of antibiotics and robust preventive measures are necessary to control its spread. No prior use of fish vaccines has been reported in Pakistan. The present study aims to develop and evaluate inactivated vaccines against local strain of A. hydrophila in Pakistan with alum-precipitate as adjuvant. The immunogenic potential of vaccine was evaluated in two Indian major carps (Rohu: Labeo rohita, Mori: Cirrhinus mrigala) and a Chinese carp (Grass carp: Ctenopharyngodon idella). Fish were vaccinated intraperitoneally followed by a challenge through immersion. Fish with an average age of 4-5 months were randomly distributed in three vaccinated groups with three vaccine concentrations of 108, 109 and 1010 colony forming unit (CFU)/ml and a control group. Fixed dose of 0.1ml was applied to each fish on 1st day and a booster dose at 15 days post-vaccination (DPV). Blood samples were collected on 14, 28, 35, 48 and 60 DPV to determine antibody titers in blood serum using compliment fixation test (CFT). Fish were challenged at 60 DPV with infectious A. hydrophila with 108 CFU/ml through immersion. Significantly higher levels of antibody titers were observed from 28 DPV in all vaccinated groups as compared to those in the control group. In challenge experiment the average RPS (relative percent survivability) was 71% for groups vaccinated with 109 and 1010 CFU/ml and 86% for 108 CFU/ml. Vaccine with 108 CFU/ml induced highest immune response followed by 109 and 1010 CFU/ml. The immune response of L. rohita and C. idella was better than that of C. mrigala. In general, normal histopathology was observed in different organs of vaccinated fish whereas minor deteriorative changes were found in fish vaccinated with higher concentrations of the vaccine.

Resumo Aeromonas hydrophila é uma causa de surtos de doenças infecciosas em espécies de carpas cultivadas em países do sul da Ásia, incluindo o Paquistão. Essa bactéria ganhou resistência a uma ampla gama de antibióticos, e medidas preventivas robustas são necessárias para controlar sua disseminação. Nenhum uso anterior de vacinas para peixes foi relatado no Paquistão. O presente estudo tem como objetivo desenvolver e avaliar vacinas inativadas contra cepa local de A. hydrophila no Paquistão com precipitado de alúmen como adjuvante. O potencial imunogênico da vacina foi avaliado em duas carpas principais indianas (Rohu: Labeo rohita, Mori: Cirrhinus mrigala) e uma carpa chinesa (Grass Carp: Ctenopharyngodon idella). Os peixes foram vacinados por via intraperitoneal, seguido de um desafio por imersão. Peixes com idade média de 4-5 meses foram distribuídos aleatoriamente em três grupos vacinados com três concentrações de vacina de 108, 109 e 1010 unidades formadoras de colônias (UFC) / ml e um grupo de controle. Foi aplicada dose fixa de 0,1ml em cada peixe no 1º dia e dose de reforço 15 dias pós-vacinação (DPV). Amostras de sangue foram coletadas em 14, 28, 35, 48 e 60 DPV para determinar os títulos de anticorpos no soro sanguíneo usando o teste de fixação de elogio (CFT). Os peixes foram desafiados a 60 DPV com infecciosa A. hydrophila com 108 CFU / ml por imersão. Níveis significativamente mais elevados de títulos de anticorpos foram observados em 28 DPV em todos os grupos vacinados, em comparação com aqueles no grupo de controle. Na experiência de desafio, o RPS médio (sobrevivência percentual relativa) foi de 71% para os grupos vacinados com 109 e 1010 CFU / ml e 86% para 108 CFU / ml. A vacina com 108 UFC / ml induziu a maior resposta imune seguida por 109 e 1010 UFC / ml. A resposta imune de L. rohita e C. idella foi melhor do que a de C. mrigala. Em geral, histopatologia normal foi observada em diferentes órgãos de peixes vacinados, enquanto pequenas alterações deteriorantes foram encontradas no grupo de controle e nos peixes vacinados com concentrações mais altas da vacina.

Blue and red light photoemitters as approach to inhibit Staphylococcus aureus and Pseudomonas aeruginosa growth / Fotoemissores de luz azul e vermelha como abordagem para inibir o crescimento de Staphylococcus aureus e Pseudomonas aeruginosa

The ability of pathogenic bacteria acquire resistance to the existing antibiotics has long been considered a dangerous health risk threat. Currently, the use of visible light has been considered a new approach to treat bacterial infections as an alternative to antibiotics. Herein, we investigated the antimicrobial effect of two range of visible light, blue and red, on Staphylococcus aureus and Pseudomonas aeruginosa, two pathogenic bacterial commonly found in healthcare settings-acquired infections and responsible for high rate of morbidity and mortality. Bacterial cultures were exposed to blue or red light (470 nm and 660 nm) provided by light-emitting diodes - LED. The fluencies and irradiance used for blue and red light were 284.90 J/cm², 13.19 mW/cm² and 603.44 J/cm², 27.93 mW/cm² respectively. Different experimental approaches were used to determine the optimal conditions of light application. Only exposure to blue light for 6 hours was able to inhibit about 75% in vitro growth of both bacterial species after 24 hours. The surviving exposed bacteria formed colonies significantly smaller than controls, however, these bacteria were able to resume growth after 48 hours. Blue light was able to inhibit bacterial growth upon inoculation in both saline solution and BHI culture medium. We can conclude that blue light, but not red light, is capable of temporarily retarding the growth of gram negative and gram positive bacteria.

A capacidade das bactérias patogênicas adquirirem resistência aos antibióticos existentes há muito tempo é considerada uma ameaça perigosa à saúde. Atualmente, o uso da luz visível tem sido considerado uma nova abordagem no tratamento de infecções bacterianas como alternativa aos antibióticos. Neste trabalho, investigamos o efeito antimicrobiano de duas faixas de luz visível, azul e vermelha, em Staphylococcus aureus e Pseudomonas aeruginosa, duas bactérias patogênicas comumente encontradas em infecções adquiridas em instituições de saúde e responsáveis por alta taxa de morbimortalidade. As culturas bacterianas foram expostas à luz azul ou vermelha(470 nm e 660 nm) fornecida por diodos emissores de luz - LED. As fluências e irradiâncias utilizadas para luz azule vermelha foram 284,90 J/cm², 13,19 mW/cm² e 603,44 J/cm², 27,93 mW/cm², respectivamente. Várias abordagens experimentais foram utilizadas para determinar as condições ótimas de aplicação da luz. Apenas a exposição à luz azul por 6 horas foi capaz de inibir cerca de 75% o crescimento in vitro de ambas as espécies bacterianas após24 horas. As bactérias expostas sobreviventes formaram colônias com um tamanho significativamente menor do que os controles, contudo, essas bactérias conseguiram retomar o crescimento normal após 48 horas. A luz azul foi capaz de inibir o crescimento das bactérias após sua inoculação em solução salina ou no meio de cultura rico em nutrientes BHI. Podemos concluir que a luz azul mas não a luz vermelha é capaz de retardar temporariamente o crescimento de bactérias Gram-negativas e Gram-positivas.

The evaluation of nosocomial infections in pediatric patients with extracorporeal membrane oxygenation support

Abstract Introduction: Extracorporeal membrane oxygenation (ECMO) has become a standard technique over the past few decades in intensive care unit (ICU). Objective: A review of pediatric patients who received ECMO support in the pediatric cardiac ICU was conducted to determine the incidence, risk factors and causal organisms related to acquired infections and assess the survival rates of ECMO patients with nosocomial infections. Methods: Sixty-six patients who received ECMO support in the pediatric cardiac ICU between January 2011 and June 2014 were included in the study. Demographic, echocardiographic, hemodynamic features and surgical procedures were reviewed. Results: Sixty-six patients received a total of 292.5 days of venoarterial ECMO support. Sixty were postoperative patients. Forty-five patients were weaned from ECMO support with an ECMO survival rate of 68.2%. The rate of infection was 116.2/1000 ECMO days. Prolonged ICU stay, duration of ventilation and ECMO were found associated with development of nosocomial infection and only the duration of ECMO was an independent risk factor for nosocomial infections in ECMO patients. Conclusion: The correction of the underlying process leading to ECMO support and shortening the length of ECMO duration together with stricter application of ECMO indications would improve the infection incidence and hospital surveillance of the patient group.

A randomized clinical trial on the effectiveness of a symbiotic product to decolonize patients harboring multidrug-resistant Gram-negative bacilli

Abstract INTRODUCTION: We aimed to evaluate the effectiveness of a symbiotic product to decolonize the intestinal tract of patients harboring multidrug-resistant (MDR) Gram-negative bacilli and to prevent nosocomial infections. METHODS: This was a randomized, double blind, placebo-controlled clinical trial, conducted in a tertiary-care university hospital. All adult hospitalized patients with a positive clinical culture and a positive rectal swab for any MDR Gram-negative bacilli were potentially eligible. Exclusion criteria were pregnancy, immunosuppression, and bowel obstruction/perforation. The intervention consisted of administering a symbiotic product (Lactobacillus bulgaricus, Lactobacillus rhamnosus, and fructo-oligosaccharides) twice a day for seven days via the oral/enteral route. RESULTS: Between August 1, 2012 and December 22, 2013, 116 of 275 eligible patients were allocated to treatment (n=57) and placebo (n=59). Overall, 101 patients received at least four doses of the study products and were included in the modified intention-to-treat analysis. The primary study outcome, a negative rectal swab for MDR Gram-negative bacilli after treatment, was identified in 16.7% (8/48) and 20.7% (11/53) of patients in the experimental and placebo group, respectively (p=0.60). The secondary outcome, the combined incidence of nosocomial respiratory and urinary tract infections, was 37.5% (18/48) in the experimental group versus 22.6% (12/53) in the control group (adjusted odds ratio: 1.95, 95% confidence interval: 0.69-5.50, p=0.21). Length of stay after the beginning of the intervention, incidence of adverse events, and in-hospital mortality rates were similar in both study groups. CONCLUSIONS: Under the present study conditions, symbiotic administration was not effective for decolonizing hospitalized patients harboring MDR Gram-negative bacilli.

Frequency of oral mucositis and microbiological analysis in children with acute lymphoblastic leukemia treated with 0.12 percent chlorhexidine gluconate

In view of the morbidity potential of oral complications in patients with leukemia, this study evaluated the clinical and microbiological alterations that occur in the oral mucosa of children with acute lymphoblastic leukemia (ALL) undergoing antineoplastic chemotherapy and prophylactic administration of 0.12 percent chlorhexidine gluconate. The sample consisted of 17 children aged 2 to 12 years that underwent clinical examination of the oral mucosa for the detection of oral lesions. In addition, biological material was collected from labial and buccal mucosa for microbiological analysis. Oral mucositis was observed in only 5 (29.4 percent) patients. Microbiological analysis revealed a reduced number of potentially pathogenic microorganisms, such as coagulase-negative staphylococci (47 percent), Candida albicans (35.3 percent), Klebsiella pneumoniae (5.9 percent), enteropathogenic Escherichia coli (5.9 percent), and Stenotrophomonas maltophilia (5.9 percent). Patients with oral mucositis showed a higher frequency of coagulase-negative staphylococci (80 percent) when compared with patients with normal oral mucosa (33.3 percent). In conclusion, the results of the present study suggest that the prophylactic use of 0.12 percent chlorhexidine gluconate reduces the frequency of oral mucositis and oral pathogens in children with ALL. In addition, the present findings suggest a possible relationship between coagulase-negative staphylococci and the development of oral mucositis.

Tendo em vista o potencial de morbidade das complicações orais em pacientes com leucemia, este estudo avaliou as alterações clínicas e microbiológicas que ocorrem na mucosa bucal de crianças com leucemia linfoblástica aguda (LLA), submetidas à quimioterapia antineoplásica e administração profilática do gluconato de clorexidina 0,12 por cento. A amostra foi constituída de 17 crianças de 2 a 12 anos, as quais foram submetidas a exame clínico da mucosa oral para a detecção de lesões bucais. Além disso, foi coletado material biológico das mucosas labial e jugal para análises microbiológicas. A mucosite oral foi observada em apenas 5 (29,4 por cento) pacientes. A análise microbiológica revelou a presença de um número reduzido de microorganismos potencialmente patogênicos, como estafilococos coagulase-negativos (47 por cento), Candida albicans (35,3 por cento), Klebsiella pneumoniae (5,9 por cento), Escherichia coli enteropatogênica (5,9 por cento) e Stenotrophomonas maltophilia (5,9 por cento). Pacientes com mucosite oral apresentaram uma maior freqüência de estafilococos coagulase-negativos (80 por cento) quando comparados aos pacientes que exibiam mucosa oral normal (33,3 por cento). Em conclusão, os resultados do presente estudo sugerem que o uso profilático do gluconato de clorexidina 0,12 por cento reduz a freqüência de mucosite oral e de patógenos orais em crianças com LLA. Além disso, os presentes achados sugerem uma possível relação entre estafilococos coagulase-negativos e o desenvolvimento de mucosite oral.

Política de prevenção da disseminação de germes multirresistentes no Hospital de Clínicas de Porto Alegre / Policy for prevention of transmission of multidrug-resistant organisms at Hospital de Clínicas de Porto Alegre

O aumento da incidência de germes multirresistentes (GMR) e a falta de opções terapêuticas a curto ou médio prazo representam um grande desafio aos hospitais no que se refere à prevenção da disseminação destas bactérias. Para a prevenção da transmissão de agentes infecciosos no ambiente hospitalar é preconizada a adoção de medidas de bloqueio epidemiológico. Essas políticas de bloqueio devem estar claramente estabelecidas, divulgadas aos profissionais de saúde e adotadas por estes a fim de minimizar a incidência de GMR. Revisamos aqui a política de prevenção da disseminação de germes multirresistentes no Hospital de Clínicas de Porto Alegre.

The increasing incidence of multidrug-resistant organisms (MDROs) and the lack of therapeutic options in the short and medium term pose a major challenge to hospitals with regard to preventing the spread of these bacteria. Infection control measures are recommended to prevent transmission of infectious agents in hospital settings. These infection control policies should be clearly established and disseminated among health professionals in order to minimize the incidence of MDROs. We reviewed a hospital policy for prevention of transmission of MDROs at Hospital de Clínicas de Porto Alegre, southern Brazil.

Infección por bacilos gram-negativos no fermentadores: Problemática en las unidades de cuidados intensivos / Infection caused by the nonfermentative gram-negative bacilli. Problematic in the intensive cares units

Las infecciones por bacilos gram-negativos no fermentadores han cobrado notoria importancia por su incidencia en las infecciones hospitalarias. Actualmente, se destaca el hallazgo de especies como la Pseudomonas aeruginosa y el Acinetobacter spp.; de este último, el Acinetobacter baumannii es la especie que con mayor frecuencia se asocia a infecciones graves y a la muerte. El aislamiento de estos patógenos se asocia a un incremento de la mortalidad y están entre los agentes que más frecuentemente causan infecciones en las Unidades de Terapia Intensiva, de ahí que constituyan desafíos terapéuticos. En el presente artículo, se realiza una revisión actualizada de la literatura y se hace énfasis en la problemática de la resistencia bacteriana y la terapéutica antibiótica(AU)

Infections caused by the nonfermentative gram-negative bacilli have charged notorious importance for their incidence in the hospital infections. At the moment it stands out the discovery of species like the Pseudomonas aeruginosa and the Acinetobacter spp.; Acinetobacter baumannii is the species that associates to severe infections and the death with more frequency. The isolation of these pathogens associates to an increment of the mortality. These pathogens are among the agents that more frequently cause infections in the Intensive Cares Units, they constitute therapeutic challenges. Presently article is made a modernized revision of the literature and emphasis is made in the problem of the bacterial resistance and the antibiotic therapy(AU)

Rotación de antimicrobianos en la Unidad de Terapia Intensiva: ¿es ésta una estrategia útil? / Cycling of antimicrobial agents in the intensive care units: Is it a useful strategy?

La resistencia antimicrobiana es un problema muy relevante en las unidades de terapia intensiva y se relaciona directamente con la mayor morbilidad, mortalidad y elevados costos que se generan en estas unidades. La rotación de antimicrobianos es una nueva herramienta en el combate de la resistencia. Existe evidencia en la literatura de su beneficio en la disminución de la emergencia de microorganismos resistentes pero la experiencia clínica no es suficiente aún y su aplicación implica todo un cambio en las normas y políticas hospitalarias obligando además a la participación comprometida de todo el estamento médico.

Descontaminaçäo intestinal seletiva: por que ainda näo utilizamos na prática clínica? / Selective descontamination of digestive system: why does not still utilize in the clinical practice?

A descontaminaçäo seletiva do trato digestivo com antibióticos näo absorvíveis tem sugerido a ocorrência de diminuiçäo da incidência de infecçäo hospitalar dos pacientes em unidades de terapia intensiva, sendo um procedimento cada vez mais utilizado. Entretanto, tal procedimento ainda näo conseguiu provar o seu valor, sendo objeto de várias críticas. O autor deste trabalho considera esta hipótese atrativa, sugerindo, porém, dever ser utilizada, neste momento, somente em trabalhos clínicos controlados