Isolation and Phenotypic Characterization of Lytic Bacteriophage with Activity against Pseudomonas aeruginosa

Aims: To perform the isolation and phenotypic characterization of bacteriophage with lytic activity against Pseudomonas aeruginosa. To demonstrate that this type of viral agent can be isolated from the environment and used for the biocontrol of resistant bacterial types, such as Pseudomonas aeruginosa. Study Design: This study was an experimental study. Place and Duration of Study: The study was conducted at, Bacteriology and Mycology Laboratory in the Veterinary Hospital at the School of Agricultural Sciences, Innovation and Business of the University of Passo Fundo (ESAN/UPF) and Center for Diagnosis and Research in Animal Health of the University of Passo Fundo (CDSA/UPF), between April 2022 and June 2022. Methodology: Samples of untreated water were inoculated with the host bacterium strain Pseudomonas aeruginosa ATCC 27853 in an enriched media After the incubation period in, a phage filtrate was obtained by centrifugation followed by filtration. We verified the presence of bacteriophages using spot test and we carried out its purification by the method of sterile toothpick plate transfer on bacterial overlay semi-solid agar. Amplification was performed using an SM buffer elution procedure to produce a stock of viral material. Through assays in Petri dishes with bacterial overlay, we performed titration and phenotypic characterization regarding the lysis spectrum and efficiency of phage infection in the host. Results: We managed to isolate a morphologically characterized lytic bacteriophage with approximately 1 mm of diameter, high clarity in the inhibition area, the presence of halo and well-demarcated edges. The bacteriophage, named as Pseudomonas aeruginosa Phage UPF_PaBP1, demonstrated the infection capacity of the target bacteria in all tested dilutions and a stock preparation with a titre of 6.5 x 10? PFU/ml was obtained for future use. Conclusion: The isolated phage showed strong lytic activity against the bacterial host, a finding that nourishes our expectations regarding the use of this phage as a biocontrol agent and phage therapy.

Characterization of a Coliphage AS1 isolated from sewage effluent in Pakistan

Abstract The emergence of multi-drug resistant (MDR) bacterial strains, which are posing a global health threat has developed the interest of scientists to use bacteriophages instead of conventional antibiotics therapy. In light of an increased interest in the use of phage as a bacterial control agent, the study aimed to isolate and characterize lytic phages from sewage effluent. During the current study, bacteriophage AS1 was isolated from sewage effluent against E.coli S2. The lytic activity of phageAS1 was limited to E.coli S2 strain showing monovalent behavior. The calculated phage titer was 3.5×109 pfu/ml. PhageAS1 was stable at a wide range of pH and temperature. The maximum stability was recorded at 37ºC and pH 7.0, while showing its normal lytic activity at temperature 60ºC and from pH 5.0 to11.0 respectively. At temperature 70ºC, phage activity was somewhat reduced whereas, further increase in temperature and decrease or increase in pH completely inactivated the phage. From the current study, it was concluded that waste water is a best source for finding bacteriophages against multi-drug resistant bacterial strains and can be used as bacterial control agent.

Resumo O surgimento de cepas bacterianas multirresistentes (MDR), que representam uma ameaça global à saúde, desenvolveu o interesse dos cientistas em usar bacteriófagos em vez da terapia convencional com antibióticos. Diante do crescente interesse no uso de fago como agente de controle bacteriano, o estudo visou isolar e caracterizar fagos líticos de efluente de esgoto. Durante o estudo atual, o bacteriófago AS1 foi isolado de efluente de esgoto contra E. coli S2. A atividade lítica de phageAS1 foi limitada à cepa E. coli S2, apresentando comportamento monovalente. O título de fago calculado foi de 3,5 x 109 ufp/ml. PhageAS1 foi estável em uma ampla faixa de pH e temperatura. A estabilidade máxima foi registrada a 37ºC e pH 7,0, enquanto mostrou atividade lítica normal em temperatura de 60ºC e pH 5,0 a 11,0, respectivamente. Na temperatura de 70ºC, a atividade do fago foi um pouco reduzida, enquanto o aumento adicional da temperatura e a diminuição ou aumento do pH inativaram completamente o fago. Com base no estudo atual, concluiu-se que a água residual é a melhor fonte para encontrar bacteriófagos contra cepas bacterianas multirresistentes e pode ser usada como agente de controle bacteriano.

Characterization of a Coliphage AS1 isolated from sewage effluent in Pakistan / Caracterização de um colifago AS1 isolado de efluente de esgoto no Paquistão

The emergence of multi-drug resistant (MDR) bacterial strains, which are posing a global health threat has developed the interest of scientists to use bacteriophages instead of conventional antibiotics therapy. In light of an increased interest in the use of phage as a bacterial control agent, the study aimed to isolate and characterize lytic phages from sewage effluent. During the current study, bacteriophage AS1 was isolated from sewage effluent against E.coli S2. The lytic activity of phageAS1 was limited to E.coli S2 strain showing monovalent behavior. The calculated phage titer was 3.5×109 pfu/ml. PhageAS1 was stable at a wide range of pH and temperature. The maximum stability was recorded at 37ºC and pH 7.0, while showing its normal lytic activity at temperature 60ºC and from pH 5.0 to11.0 respectively. At temperature 70ºC, phage activity was somewhat reduced whereas, further increase in temperature and decrease or increase in pH completely inactivated the phage. From the current study, it was concluded that waste water is a best source for finding bacteriophages against multi-drug resistant bacterial strains and can be used as bacterial control agent.

O surgimento de cepas bacterianas multirresistentes (MDR), que representam uma ameaça global à saúde, desenvolveu o interesse dos cientistas em usar bacteriófagos em vez da terapia convencional com antibióticos. Diante do crescente interesse no uso de fago como agente de controle bacteriano, o estudo visou isolar e caracterizar fagos líticos de efluente de esgoto. Durante o estudo atual, o bacteriófago AS1 foi isolado de efluente de esgoto contra E. coli S2. A atividade lítica de phageAS1 foi limitada à cepa E. coli S2, apresentando comportamento monovalente. O título de fago calculado foi de 3,5 x 109 ufp/ml. PhageAS1 foi estável em uma ampla faixa de pH e temperatura. A estabilidade máxima foi registrada a 37ºC e pH 7,0, enquanto mostrou atividade lítica normal em temperatura de 60ºC e pH 5,0 a 11,0, respectivamente. Na temperatura de 70ºC, a atividade do fago foi um pouco reduzida, enquanto o aumento adicional da temperatura e a diminuição ou aumento do pH inativaram completamente o fago. Com base no estudo atual, concluiu-se que a água residual é a melhor fonte para encontrar bacteriófagos contra cepas bacterianas multirresistentes e pode ser usada como agente de controle bacteriano.

Characterization of a Coliphage AS1 isolated from sewage effluent in Pakistan / Caracterização de um colifago AS1 isolado de efluente de esgoto no Paquistão

The emergence of multi-drug resistant (MDR) bacterial strains, which are posing a global health threat has developed the interest of scientists to use bacteriophages instead of conventional antibiotics therapy. In light of an increased interest in the use of phage as a bacterial control agent, the study aimed to isolate and characterize lytic phages from sewage effluent. During the current study, bacteriophage AS1 was isolated from sewage effluent against E.coli S2. The lytic activity of phageAS1 was limited to E.coli S2 strain showing monovalent behavior. The calculated phage titer was 3.5×109 pfu/ml. PhageAS1 was stable at a wide range of pH and temperature. The maximum stability was recorded at 37ºC and pH 7.0, while showing its normal lytic activity at temperature 60ºC and from pH 5.0 to 11.0 respectively. At temperature 70ºC, phage activity was somewhat reduced whereas, further increase in temperature and decrease or increase in pH completely inactivated the phage. From the current study, it was concluded that waste water is a best source for finding bacteriophages against multi-drug resistant bacterial strains and can be used as bacterial control agent.

O surgimento de cepas bacterianas multirresistentes (MDR), que representam uma ameaça global à saúde, desenvolveu o interesse dos cientistas em usar bacteriófagos em vez da terapia convencional com antibióticos. Diante do crescente interesse no uso de fago como agente de controle bacteriano, o estudo visou isolar e caracterizar fagos líticos de efluente de esgoto. Durante o estudo atual, o bacteriófago AS1 foi isolado de efluente de esgoto contra E. coli S2. A atividade lítica de phageAS1 foi limitada à cepa E. coli S2, apresentando comportamento monovalente. O título de fago calculado foi de 3,5 x 109 ufp/ml. PhageAS1 foi estável em uma ampla faixa de pH e temperatura. A estabilidade máxima foi registrada a 37ºC e pH 7,0, enquanto mostrou atividade lítica normal em temperatura de 60ºC e pH 5,0 a 11,0, respectivamente. Na temperatura de 70ºC, a atividade do fago foi um pouco reduzida, enquanto o aumento adicional da temperatura e a diminuição ou aumento do pH inativaram completamente o fago. Com base no estudo atual, concluiu-se que a água residual é a melhor fonte para encontrar bacteriófagos contra cepas bacterianas multirresistentes e pode ser usada como agente de controle bacteriano.

Research progress on Streptococcus mutans phages in the prevention of dental caries / 口腔疾病防治

@#The Streptococcus mutans (S. mutans) phage, as one of the principal pathogenic bacteria of dental caries, is a main cause of the formation and development of dental caries due to its overproliferation in dental plaque biofilms. Bacterial viruses, also known as bacteriophages, have the capability of specifically infecting bacteria and effectively degrading bacterial biofilms. S. mutans phages, therefore, may prevent and control caries. Therapy based on phages has been applied in many fields, but the application of S. mutans phages in caries remains exploratory. This article will review the research progress of S. mutans phages in clinical caries prevention, aiming to provide a new idea for the clinical prevention of caries. The results of the literature review show that the living bacteriophage system has the advantages of high specificity, high affinity and good safety. However, due to its unstable structure, it can be processed into a more stable formulation by freeze-drying, spray drying, adding stability enhancers, or incorporating bacteriophages into ointments, biodegradable polymer matrices or particles to a certain extent to improve stability. The lysozyme produced by phages can digest the bacterial cell wall and release the assembled phage particles, which effectively cleave biofilms. In addition, the antigen binding fragment library for cariogenic pathogens was screened by phage display technology, and the purpose of caries prevention and treatment was achieved by passive immunization of antigen binding fragments. However, the host range of bacteriophages is narrow, so this kind of problem can be overcome by phage combined with traditional therapy or other drug use or cocktail therapy with multiple phages in clinical caries prevention and control.

Clinical utilization of bacteriophages: a new perspective to combat the antimicrobial resistance in Brazil

ABSTRACT Due to the emergence of multi-drug resistant bacteria, and the evident limitation in therapeutic options, alternatives to combat bacterial infections have been sought. One of these is phage therapy, which is the use of bacterial viruses to kill pathogenic bacteria responsible for the infection. These viruses called bacteriophages are very abundant organisms in the world and are harmless to humans. There are several advantages in using phage therapy, especially against multi-drug resistant pathogens, which tend to be dominated by individual strains. The advantages include fewer collateral effects such as lower disturbance of gut microbiota and less antimicrobials consumption, which itself leads to reducing antibiotic resistance rates. Unfortunately, few clinical studies have been initiated in Brazil and this area is little explored in our country. This manuscript describes clinical evidence of successful phage utilization on pathogens considered a threat in Brazil, highlighting the benefits of a possible phage utilization as an important tool to combat antimicrobial resistance in our country.

Influence of some environmental variables and addition of r-lysozyme on efficacy of Vibrio harveyi phage for therapy

Bacteriophage therapy is a viable proposition for controlling luminous vibriosis caused by Vibrio harveyi in shrimpaquaculture. However, environmental factors influence the growth and activity of phage and affect its efficiency incontrolling bacterial diseases. An essential problem in the use of vibrio phage as a therapeutic agent was the development ofresistance to phage attachment, rendering them resistant to the lytic action of phage. This problem could be overcome byapplying a cocktail of phages. This study aimed to evaluate the effect of salinity and pH on the phage activity and also tostudy the role of recombinant shrimp lysozyme on the performance of the V. harveyi phage. Out of three different levels ofsalinity (20, 25 and 30 ppt) and pH (6, 7 and 8) tested, optimum phage activity was observed at a salinity of 25 ppt and atneutral pH. Application of recombinant shrimp lysozyme in combination with V. harveyi phage significantly improved theactivity of phage in in vitro assay as well as in microcosm study using seawater. The application of phage along withlysozyme can be a useful approach to overcome the inability of phage to enter the bacteria and thus eliminate or reduce fish/shrimp pathogenic bacteria in aquaculture.

Advances in the research of application of immune modulation of phage in treatment of sepsis / 中华烧伤杂志

Phages are traditionally deemed to lyse host bacteria, while new evidences have convinced their immunomodulation effects in metazoan hosts during period of anti-infection treatment. For sepsis induced by bacteria, phage therapy has attracted widespread attention of researchers at home and abroad for its lytic and immunoregulation functions. Clinical and basic researches in mechanism, usage, dosage, and safety of phages in China are inadequate and urgent to be carried out in depth and strengthened. Here we review overall anti-inflammation functions of phages in the treatment of sepsis, influence of phages in human immune cells, and clinical advances in present researches of phage therapy for sepsis.

Bacteriophages in the control of pathogenic vibrios

Vibrios are common inhabitants of marine and estuarine environments. Some of them can be pathogenic to humans and/or marine animals using a broad repertory of virulence factors. Lately, several reports have indicated that the incidence of Vibrio infections in humans is rising and also in animals constitute a continuing threat for aquaculture. Moreover, the continuous use of antibiotics has been accompanied by an emergence of antibiotic resistance in Vibrio species, implying a necessity for efficient treatments. One promising alternative that emerges is the use of lytic bacteriophages; however, there are some drawbacks that should be overcome to make phage therapy a widely accepted method. In this work, we discuss about the major pathogenic Vibrio species and the progress, benefits and disadvantages that have been detected during the experimental use of bacteriophages to their control.

Bacteriophage and its application in ocular diseases / 中华实验眼科杂志

Phage (bacteriophage) is a kind of viruses which can infect bacteria,actinomyces and spirochetes.The phage can only reproduced by host bacteria instead of living independently.The process of phage reproduction is also the process of sterilization.Nowadays,the "post-antibiotic era" that leading by global rise in bacterial resistance,urges scientists to explore alternative therapies for antibiotics.The phage therapy has attracted the attention of researchers.Several researchers has successfully treated bacterial keratitis,endophthalmitis and conjunctivitis by using bacteriophage and phage lyzyme.Phage not only kills pathogenic bacteria,but also maintains the structural integrity of eye.This article reviewed the phage structure and classification,the process of its discovery and development,the bactericidal mechanism of phage,its application and therapeutic characteristics in the treatment of ophthalmological diseases.

Phage therapy: progress in pharmacokinetics

ABSTRACT The concept of phage therapy exists in the history and it has been ignored for a long time, but the consequence of drug resistance in pathogen bacteria has forced the forgotten kingdom of phage therapy to be re-explored. However, for the successful implementation and acceptance of phage therapy worldwide, the number of factors need to be addressed. In pharmacology of phage therapy, pharmacodynamics is a straightforward concept, on the other hand, owing to the unique feature of phages to replicate and their high sensitivity, pharmacokinetics is rather complex. In this review, we have discussed pharmacokinetics and some recent advances in delivery systems as to achieve the therapeutically effective concentrations of phage in their activated form.

Efeito antimicrobiano do bacteriófago geneticamente modificado φEf11/φFL1C(Δ36)PnisA sobre cepas de E. faecalis em biofilme estático e em canais radiculares infectados / Antibacterial effect of a Genetically-Engineered Bacteriophage φEf11/φFL1C(Δ36)PnisA on static biofilms and on Dentin Infected with E. faecalis

A presença de micro-organismos no sistema de canais radiculares (SCR) tem sido apontada como uma das principais causas de insucesso da terapia endodôntica. A capacidade de formar biofilme e penetrar nos túbulos dentinários são fatores de sobrevivência que favorecem a perpetuação de micro-organismos no interior do SCR. Terapias que promovam a desorganizazão de biofilmes e eliminação de bactérias dentro dos túbulos dentinários são fundamentais para a desinfecção endodôntica. Uma terapia descoberta há um século, denominada de Bacteriofagoterapia, baseia-se na utilização de vírus capazes de infectar e matar bactérias. Esta abordagem antimicrobiana tem recebido bastante atenção atualmente por representar uma alternativa para o tratamento de doenças causadas por bactérias multirresistentes aos antibióticos. O objetivo deste estudo foi avaliar a eficácia de um bacteriófago modificado geneticamente, φEf11/φFL1C(Δ36)PnisA, para eliminar biofilmes de duas cepas de E. faecalis: JH2-2 (sensível à vancomicina e resistente ao ácido fusídico e à rifampicina) e V583 (resistente à vancomicina). Este estudo foi dividido em dois experimentos distintos. No primeiro experimento, biofilmes estáticos de 48 horas de cepas de E. faecalis JH2-2 (pMSP3535 nisR / K) ou V583 (pMSP3535 nisR / K) formados em lâminulas de vidro (coverslips) foram inoculados por suspensão do bacteriófago φEf11/φFL1C(Δ36)PnisA. Após 48 horas de incubação, a biomassa bacteriana foi fotografada por microscopia confocal e as células viáveis foram quantificadas por medição de unidades formadoras de colônias (UFC). No segundo experimento, segmentos radiculares de dentes humanos extraídos foram cimentados em dispositivos vedáveis de duas câmaras para formar modelos ex vivo com dentina infectada, contendo solução tampão na câmara inferior. Os modelos foram inoculados com uma suspensão de E. faecalis V583 ou E. faecalis JH2-2. Após sete dias de incubação a 37°C, adicionou-se ao canal de cada segmento de dentina infectada dos grupos 2 e 5 uma suspensão do fago geneticamente modificado, φEf11/φFL1C(Δ36)PnisA e manteve-se a incubação por mais 72 horas. Os segmentos de dentina foram instrumentados com Gates Glidden e a solução tampão foi aliquotada para semeadura e contagem de UFC e aferição do título residual de células de E. faecalis. Os resultados do primeiro experimento mostraram uma diminuição de 10-100 vezes (p≤ 0,05) das células viáveis (UFC / biofilme) após tratamento com bacteriófago, o que foi consistente com a comparação das imagens de biofilme tratado e não tratado visualizadas com projeções máximas da série Z. No segundo experimento a titulação de E. faecalis verificada após tratamento com o bacteriófago foi reduzida em 18% para os modelos infectados com JH2-2 e em 99% (p≤ 0,05) nos modelos infectados com V583. Com base nesses resultados, pode-se concluir que a biomassa dos biofilmes de E. faecalis, tanto sensíveis quanto resistentes à vancomicina, foi significantemente reduzida após a infecção pelo bacteriófago φEf11/φFL1C(Δ36)PnisA. Além disso, o tratamento da dentina infectada por E. faecalis com bacteriófago φEf11/φFL1C(Δ36)PnisA resultou em diminuição da população bacteriana residual de cepas sensíveis e resistentes à vancomicina, alcançando significância estatística no grupo que utilizou a cepa V583.

Residual microorganisms in the root canal system (RCS) have been identified as the main cause of endodontic therapy failure. The ability to form a biofilm and penetrate the dentin tubules are survival factors that favor the perpetuation of microorganisms within the RCS. Therapies that promote the disorganization of biofilms and elimination of bacteria within the dentinal tubules are essential for endodontic disinfection. A therapy discovered a century ago called Bacteriophage Therapy is based on the use of viruses capable of infecting and killing bacteria. Recently, this antimicrobial approach has been receiving considerable attention since it represents an alternative for the treatment of diseases caused by multiresistant antibiotic bacteria. The aim of this study was to evaluate the efficacy of a genetically engineered bacteriophage, φEf11/φFL1C(Δ36)PnisA, to disrupt biofilms of two Enterococcus faecalis strains: JH2-2 (vancomycin sensitive) and V583 (vancomycin resistant). This study was divided into two separate experiments. In the first experiment, 24 hour static biofilms of E. faecalis strains JH2-2(pMSP3535 nisR/K) and V583(pMSP3535 nisR/K) formed on cover slips were inoculated with bacteriophage φEf11/φFL1C(Δ36)PnisA. After 24 and 48 hours incubation, the bacterial biomass was imaged by confocal microscopy and viable cells were quantified by colony forming unit (CFU) measurement. In the second experiment, extracted human dentin root segments were cemented into sealable two-chamber devices, fabricated from syringe needle caps to form in vitro infected-dentin models. The models were inoculated with an overnight suspension of either E. faecalis V583 (vancomycin resistant strain) or E. faecalis JH2-2 (fusidic acid and rifampin resistant, vancomycin sensitive strain). After 7 days of incubation at 37°C, a suspension of a genetically engineered phage, φEf11/φFL1C(Δ36)PnisA, was added to the root canal of each infected dentin segment, and the incubation was continued for an additional 72-hours. Dentin was harvested from the walls of each root canal and assayed for the residual titer of E. faecalis cells. The results from the first experiment showed a 10-100-fold fewer decrease in viable cells (CFU/biofilm) after bacteriophage treatment, which was consistent with comparisons of treated and untreated biofilm images visualized as max projections of the Z-series. On the second experiment, the recovered E. faecalis titer was reduced by 18% for the JH2-2 infected models, and by 99% for the V583 infected models. These results suggest that the biomass of E. faecalis biofilms, both sensitive and resistant to vancomycin, was significantly reduced after infection by bacteriophage φEf11/φFL1C(Δ36)PnisA. In addition, treatment of E. faecalis-infected dentin with the phage resulted in the decrease of the residual bacterial population for both susceptible and vancomycin resistant strains, reaching statistical significance in strain V583 group.

Phage therapy of staphylococcal chronic osteomyelitis in experimental animal model.

Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) are the commonest cause of osteomyelitis. The aim of this study was to evaluate the role of an alternative therapy i.e. application of S. aureus specific bacteriophages in cases of osteomyelitis caused by MRSA in animal model. Methods: Twenty two rabbits were included in this study. The first two rabbits were used to test the safety of phage cocktail while the remaining 20 rabbits were divided into three groups; group A (n=4) to assess the establishment of osteomyelitis; group B (n=4) osteomyelitis developed but therapy started only after six weeks; and group C (n=12) osteomyelitis developed and therapy started after three weeks. Groups B and C rabbits were treated with four doses of cocktail of seven virulent bacteriophages at the interval of 48 h. Comparison between three groups was made on the basis of observation of clinical, radiological, microbiological, and histopathological examinations. Results: Experimental group rabbits recovered from the illness in the subsequent two weeks of the therapy. Appetite and activity of the rabbits improved, local oedema, erythema and induration subsided. There were minimal changes associated with osteomyelitis in X-ray and histopathology also showed no signs of infection with new bone formation. Control B group rabbits also recovered well from the infection. Interpretation & conclusions: The present study shows a potential of phage therapy to treat difficult infections caused by multidrug resistant bacteria.

Fagoterapia, alternativa para el control de las infecciones bacterianas. Perspectivas en Colombia / Phage-therapy, an alternative to control bacterial infections. Perspectives in Colombia / Fagoterapia, alternativa para o controle das infeccóes bacterianas. Perspectivas na Colombia

La capacidad de las bacterias para adquirir resistencia a agentes antimicrobianos ha reducido el número de antibióticos efectivos para combatir infecciones bacterianas. De otro lado, existen bacterias contaminantes de alimentos, que no pueden controlarse con antibióticos por tratarse de productos de consumo humano, lo que se traduce en pérdidas económicas y riesgos para la salud. Si a esto se suma la falta de desarrollo de nuevos antibióticos, es evidente que se requiere desarrollar otras estrategias para el tratamiento y control de las bacterias. Los bacteriófagos (fagos), virus que infectan bacterias, se proponen como uno de estos tratamientos alternativos en una estrategia conocida como fagoterapia. Diversos estudios han evaluado y demostrado su efectividad contra bacterias patógenas y ya existen empresas privadas que desarrollan productos basados en cocteles de fagos para controlar algunas infecciones bacterianas. En Colombia no existen antecedentes del uso de fagos pero estos representan una gran oportunidad para el aprovechamiento de la diversidad de la microbiota nativa. En este artículo presentamos las perspectivas de uso de la fagoterapia en Colombia como tratamiento de infecciones bacterianas.

Bacteria easily acquire resistance to antimicrobial agents and this reduces the number of effective antibiotics available to treat bacterial infections. Food contamination by bacteria also generates important economic losses and health risks. Products for human consumption must be free of antibiotics used in clinical treatments, and the control of bacteria with antimicrobials is strictly regulated; however, there is a lack of development of new antibiotics. As a result, the development of new antimicrobial strategies is vital. Viruses that infect bacteria called bacteriophages (phages) have been proposed as an alternative treatment in an approach known as phage-therapy. Several studies have evaluated and demonstrated their effectiveness against pathogenic bacteria; currently, there are private companies dedicated to the development of new products based on phage cocktails, to control some bacterial infections. In Colombia, there is no previous information about the use of phages, but phage-therapy represents a great opportunity to use the diversity of the native microbiota. In this review, we present the perspectives for phage-therapy in Colombia as a treatment against bacterial infections.

A capacidade das bactérias para adquirir resistencia a agentes antimicrobianos tem levado a que o número de antibióticos efetivos para combater infectes bacterianas em humanos seja cada vez menor. Nos alimentos se reportam bactérias causantes de contaminares que representam grandes perdas económicas e riscos para a saúde; estas bactérias nao podem ser tratadas com antibióticos por tratar-se de produtos para consumo humano. Tendo em conta a situado, e a falta de novos antibióticos, precisa-se do desenvolvimento de novas estratégias para o tratamento e controle das bactérias. Os bacteriófagos (fagos), vírus que infectam bactérias, propoem-se como um destes tratamentos alternativos, numa estratégia conhecida como fagoterapia. Diversos estudos tem demostrada a efetividade contra bactérias patógenas e já existem empresas privadas desenvolvendo produtos baseados em coqueteis de fagos, para controlar algumas infectes bacterianas. Na Colombia nao existe antecedente do uso de fagos, mas este apresenta uma grande oportunidade para o aproveitamento da diversidade da microbiota nativa. Nesta revisao apresentamos as perspectivas para a fagoterapia na Colombia como tratamento alternativo contra infectes bacterianas.

Characterization of a Vibrio parahaemolyticus Phage Isolated from Marine

A novel bacteriophage, designated as VPP97, that infects the strains of Vibiro parahaemolyticus (hallophilic, Gram-negative bacterium) isolated most commonly from marine environments, has been discovered, and several of its properties have been determined. The plaques were clear and sized 0.6-1.0 mm in diameter. The virion forms a single band on 70% sucrose gradient and p1.50 CsC1 gradient by sucrose gradient centrifugation and CsCI gradient centrifugation respectively. It has a hexagonal head and a relatively long tail, as shown by electron microscopy. Vibrio alginolyticus, Vibrio fluvialis and Vibrio furnissii were also sensitive to this phage It was almost totally inactivated at 70 degree C and at pH below 5 or over 10. The nucleic acid of VPP97 is composed of DNA. The VPP97 had 9 specific structural proteins sized between 21.5 kDa and 97.4 kDa on SDS-PAGE. When V. parahaemolyticus cultures were treated with either phage VPP97 or one of the several antibiotics for 2 hours, the viable number of V. parahaemolyticus treated with the phage VPP97 is lower than that treated with chloramphenicol, erythromycin or penicillin, but not lower than that treated with tetracycline. Mice that have responded to the phage treatment revealed the lower numbers of V. parahaemolyticus in small intestine and less damage on small intestine compared to the untreated mice. Therefore, we suggest that the phage treatment appears effective to the infection by V. parahaemolyticus.