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.

A Novel PCR Assay for Detecting Brucella abortus and Brucella melitensis

OBJECTIVES: Brucellosis is a major zoonotic disease that poses a significant public health threat worldwide. The classical bacteriological detection process used to identify Brucella spp. is difficult and time-consuming. This study aimed to develop a novel molecular assay for detecting brucellosis. METHODS: All complete sequences of chromosome 1 with 2.1-Mbp lengths were compared among all available Brucella sequences. A unique repeat sequence (URS) locus on chromosome 1 could differentiate Brucella abortus from Brucella melitensis. A primer set was designed to flank the unique locus. A total of 136 lymph nodes and blood samples were evaluated and classified by the URS-polymerase chain reaction (PCR) method in 2013–2014. RESULTS: Biochemical tests and bacteriophage typing as the golden standard indicated that all Brucella spp. isolates were B. melitensis biovar 1 and B. abortus biovar 3. The PCR results were the same as the bacteriological method for detecting Brucella spp. The sensitivity and specificity of the URS-PCR method make it suitable for detecting B. abortus and B. melitensis. CONCLUSION: Quick detection of B. abortus and B. melitensis can provide the most effective strategies for control of these bacteria. The advantage of this method over other presented methods is that both B. abortus and B. melitensis are detectable in a single test tube. Furthermore, this method covered 100% of all B. melitensis and B. abortus biotypes. The development of this URS-PCR method is the first step toward the development of a novel kit for the molecular identification of B. abortus and B. melitensis.

An etiological survey on a foodborne disease epidemic outbreak caused by Salmonella enteritidis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To conduct an etiological molecular epidemiological survey and laboratory test on a foodborne disease epidemic outbreak to make clear of the cause and implement effective prevention and control on it.</p><p><b>METHODS</b>On May 12th 2012, 135 kindergarten children were sent to Xuzhou City People's Hospital and Children's Hospital with gastrointestinal infection disease. A total of 34 anus swab samples and 4 vomit samples were collected from the patients. Real-time PCR rapid detection, strains separation and cultivation, phage lysis experiments, ATB automated identification system were used to make etiological detection and identification. The genomic DNA of salmonella enteritidis were typed with the pulsed-field gel electrophoresis (PFGE), cluster analysis were carried out together with the patterns of local Salmonella infections.</p><p><b>RESULTS</b>Children in 20 classes were suffered from the gastrointestinal infection among the 21 classes. There were no significant aggregation of class distribution. Among the 135 patients, 76 were boys (56.3%) and 59 were girls (43.7%). The main symptoms were fever (above 38°C), diarrhea and bellyache. Through real-time PCR detection and strains separation, 19 salmonella enteritidis were isolated from 34 anus swab samples of suspected cases and the detection rate was 56%. There were no strains detected from vomit samples. All of the 19 salmonella enteritidis showed the same serological subtype, biochemical reaction, drug sensitivity and phage lysis pattern. The salmonella enteritidis had the identical PFGE pattern (100% similarity), and were different from the pattern of local sporadic infection cases.</p><p><b>CONCLUSION</b>It was confirmed that this was an epidemic outbreak of foodborne disease caused by homologous salmonella enteritidis by epidemiological survey, clinical information, lab etiological test and molecular typing.</p>

Prevalence of R-type ACSSuT in strains of Salmonella serovar Typhimurium DT193 isolated from human infections in Brazil / Prevalencia de resistencia de tipo ACSSuT en cepas de Salmonella serovariedad Typhimurium DT193 aisladas a partir de infecciones humanas en el Brasil

OBJECTIVE: To determine the prevalence of resistance to ampicillin, chloramphenicol, streptomycin, sulphonamides, and tetracyclines (ACSSuT) in Salmonella serovar Typhimurium definitive [phage] type (DT) 193 strains isolated from human sources over the last four decades. METHODS: From 2008 to 2010, 553 DT193 isolates out of 810 human-origin Salmonella ser. Typhimurium phage-typed strains isolated from the 1970s through 2008 were selected and tested for ACSSuT resistance: 91 strains isolated during the 1970s, 65 from the 1980s, 70 from the 1990s, and 327 from 2000-2008. Resistance profiles were determined using the disk diffusion method. RESULTS: †An antimicrobial susceptibility assay indicated 20.9 percent, or 116, of all isolates tested were ACSSuT-resistant, 52.0 percent (287) were resistant to one or more drugs in the ACSSuT profile, and 27.1 percent (150) were nonresistant (susceptible to antimicrobials). Based on the assay, overall antimicrobial resistance was extremely high in the 1970s (affecting 99.0 percent of isolates from that period) and remained high during the 1980s, when 95.4 percent of isolates had some type of antimicrobial resistance and incidence of Salmonella ser. Typhimurium DT193 R-type ACSSuT increased to 73.8 percent. R-type ACSSuT dropped to 27.1 percent (19 isolates) during the 1990s, and to 5.2 percent (17) during 2000-2008, despite a substantial increase in the number of isolates tested (397 versus 204, 111, and 98, respectively, for the previous three decades). CONCLUSIONS: †Although prevalence of Salmonella ser. Typhimurium DT193 R-type ACSSuT in Brazil has decreased since the 1970s, ACSSuT resistance markers continue to circulate. Therefore, continuous surveillance should be conducted to evaluate the occurrence of Salmonella ser. Typhimurium DT193 and its antimicrobial resistance.

OBJETIVO: Determinar la prevalencia de resistencia a la ampicilina, el cloranfenicol, la estreptomicina, las sulfonamidas y las tetraciclinas (ACSSuT) en cepas de Salmonella serovariedad Typhimurium fagotipo definitivo (DT) 193 aisladas de fuentes de origen humano durante las cuatro últimas décadas. MÉTODOS: Entre el 2008 y el 2010 se seleccionaron 553 aislados de DT193 entre 810 cepas de Salmonella serovariedad Typhimurium fagotipificadas aisladas desde la década de 1970 hasta el 2008, y en ellos se analizó la resistencia a ACSSuT: se estudiaron 91 cepas aisladas durante la década de 1970, 65 aisladas durante la década de 1980, 70 aisladas durante la década de 1990, y 327 aisladas entre el 2000 y el 2008, respectivamente. Los perfiles de resistencia a los antibióticos se determinaron mediante el método de difusión en disco. RESULTADOS: El antibiograma indicó que 20,9 por ciento (116) de todos los aislados que se analizaron fueron resistentes a ACSSuT, 52,0 por ciento (287) fueron resistentes a uno o más antibióticos del grupo ACSSuT y 27,1 por ciento (150) no fueron resistentes (es decir, fueron sensibles a dichos antibióticos). Según el análisis, la resistencia general a los antibióticos fue muy alta en la década de 1970 (y comprendió a 99,0 por ciento de los aislados de ese período) y continuó siendo alta durante la década de 1980, cuando 95,4 por ciento de los aislados presentó algún tipo de resistencia a los antibióticos y la incidencia de Salmonella serovariedad Typhimurium DT193 con resistencia de tipo ACSSuT aumentó hasta 73,8 por ciento. La resistencia de tipo ACSSuT descendió a 27,1 por ciento (31 aislados) durante la década de 1990, y a 5,2 por ciento (17 aislados) entre el 2000 y el 2008, a pesar del aumento importante en el número de aislados que se evaluaron (397 frente a 204, 111 y 98 en las tres décadas anteriores, respectivamente). CONCLUSIONES: Aunque la prevalencia de Salmonella serovariedad Typhimurium DT193 con resistencia de tipo ACSSuT en el Brasil ha disminuido desde la década de 1970, los marcadores de resistencia a ACSSuT continúan en circulación. Por consiguiente, debe llevarse a cabo una vigilancia permanente para evaluar la aparición de infecciones por Salmonella serovariedad Typhimurium DT193 y su resistencia a los antibióticos.

Epidemic by Salmonella I 4,5,12:i:- and Characteristics of Isolates in Korea

BACKGROUND: Salmonella I 4,[5],12:i:- was first reported as a new serovar by the Spanish National Reference Laboratory in 1997. Thereafter, several outbreaks caused by this serovar have been reported, indicating worldwide transmission. MATERIALS AND METHODS: Stool samples and patient data were collected from diarrhea cases in an outbreak at Daegu city in 2008. Salmonella isolates were characterized by phage typing, antibiotic resistance profile and flagella gene deletion. Deposited isolates in the EnterNet-Korea, acute diarrheal surveillance system, were also screened for this serovar. RESULTS: Isolates from diarrhea patients in the Daegu outbreak (2008) were identified as Salmonella I 4,[5],12:i:-. Screening the deposited isolates in the EnteroNet-Korea revealed that an unidentifed isolate in 2001 was the Salmonella I 4,[5], 12:i:-. CONCLUSIONS: Salmonella I 4,[5],12:i:-. was the causative pathogen of the 2008 foodborne outbreak of salmonellosis in Daegu City. Retrospective screening revealed that Salmonella I 4,[5],12:i:- was present in Korea as early as 2001.

Evolución de los serotipos, fagotipos y resistencia a antimicrobianos de Salmonella sp en el departamento de salud 02 de la provincia de Castellón, España (2000-2006) / Evolution of serotypes, phagotypes and antibiotic resistance of Salmonella spp in the 02 health district of Castellón, Spain (2000-2006)

Retrospective study of serotypes, phage types and antibiotic resistance of Salmonella spp isolates in the 02 Health District of Castellón, Spain (2000-2006). Strains were serotyped using commercial sera, and they were tested for antimicrobial susceptibility with automated systems. Serotyping confirmation and phage typing were performed by the National Reference Laboratory. A total of 1505 strains were isolated, with 49 different serotypes, being the most frequent Enteritidis. The most common serotype/phage type combination was S. Enteritidis phagetype 1. Of the isolates 81.6 percent were susceptible to amoxicillin/clavulanic acid; 65.2 percent to ampicilin; 99.9 percent to ciprofloxa-cin; 93.4 percent to trimethoprim-sulphametoxazole; and 99.8 percent to cefotaxime. Molecular methods could be useful to complete epidemiologic studies since 25 percent of our isolates showed the same serotype/phage type combination. In our health district antimicrobial resistance in Salmonella is not an important problem.

Mycobacteriophages as versatile tools for genetic manipulation of mycobacteria and development of simple methods for diagnosis of mycobacterial diseases / Micobacteriófagos como herramientas versátiles para la manipulación genética y el desarrollo de métodos simples para el diagnóstico de enfermedades micobacterianas

Tuberculosis, caused by Mycobacterium tuberculosis, is responsible for over two million deaths per year worldwide. Due to its long doubling time (18 h), the microbiological detection of M. tuberculosis by conventional methods takes up to one month, unless the number of bacilli in the biological sample is high enough. Thus, drug resistance assessment requires at least one month for obtaining the primary culture and another month to determine its susceptibility to antimycobacterial drugs. Moreover, for a long time, the lack of genetic tools for mycobacteria has been a barrier for undertaking studies aimed at understanding the mechanisms of drug resistance and drug target identification, being all these topics of utmost importance considering the increase in the number of drug-resistant clones and the few therapeutic options available. Mycobacteriophages are promising as a novel source of genetic elements for mycobacteria manipulation, as well as for the development of versatile, simple, fast and cheap methods for drug resistance assessment of M. tuberculosis clinical isolates. We herein describe the background related to the use of mycobacteriophages, with emphasis placed on their utilization for drug resistance analysis in our country.

La tuberculosis, enfermedad causada por el bacilo Mycobacterium tuberculosis, es responsable de más de dos millones de muertes anuales en el mundo. Debido a su largo tiempo de duplicación (18 h), la detección bacteriológica de M. tuberculosis por métodos convencionales necesita de un mes o aun más, a menos que el número de bacilos en la muestra clínica sea suficientemente alto. Por consiguiente, se necesita un mínimo de dos meses para determinar la resistencia de este microorganismo a las drogas antituberculosas: uno para obtener el cultivo primario y otro para ensayar la sensibilidad frente a aquellas. La falta de herramientas para la manipulación genética de micobacterias ha dificultado la identificación de los blancos de acción de las drogas y el estudio de los mecanismos de resistencia a éstas, tópicos de la mayor relevancia dado el aumento mundial del número de aislamientos clínicos multirresistentes y las pocas opciones terapéuticas disponibles. Los micobacteriófagos son considerados nuevas herramientas para la manipulación de las micobacterias, así como para el desarrollo de métodos simples, rápidos y económicos para determinar la sensibilidad a drogas de los aislamientos clínicos de M. tuberculosis. En esta revisión se describen los antecedentes del uso de micobacteriófagos con énfasis en su utilización para el análisis de resistencia a drogas antituberculosas en nuestro país.

Molecular characterization of Vibrio cholerae phage-type 6b epidemic isolates from 1998 to 2001 in Sichuan province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the molecular characteristics of phage-type 6b isolates emerging in 1998-2001 cholera epidemics in Sichuan province.</p><p><b>METHODS</b>Isolates were analyzed by phage-typing, pulsed field gel electrophoresis (PFGE) and ompW gene sequencing.</p><p><b>RESULTS</b>All phage-type 1b and 6b isolates in Sichuan province from 1998 to 2001 were toxigenic. A total of 24 patterns were identified after PFGE analysis, and one predominant pattern consisted of 13 isolates. Several 1b and 6b isolates from Sichuan and isolates of the 1b from other provinces showed the same PFGE pattern. Mutation in ompW gene was found in 6b isolates.</p><p><b>CONCLUSION</b>V.cholerae O1 6b isolates in Sichuan province from 1998 to 2001 have special genetic markers, and might genetically correlate with contemporaneous 1b isolates.</p>

Isolation, drug resistance and molecular characterization of Salmonella isolates in northern Morocco

Objectives: The objective of this investigation was to assess the methods for the characterization of Salmonella isolates and to identify relationships of Salmonella isolates from human and food sources in northern Morocco. Methodology: Several Salmonella serotypes were isolated from human and food samples and were characterized using conventional culture methods, biochemical, serological, antimicrobial testing, and phage typing. Molecular analyses such as enterobacterial repetitive intergenic consensus(ERIC) - PCR, macrorestriction profiling by pulsed - field gel electrophoresis (PFGE), and virulence gene analysis were also performed. Results: Sixteen Salmonella strains were isolated in our laboratory, serotyped and identified as S. Kottbus, S. Indiana, S. London, S. Typhi, S. Hadar, S. Corvallis, S. Mbandaka, S. Ouakam, S. Tm var. cop., S. Virchow, and S. Altona. The most common resistance profiles for the isolates was ATCFATSCGKSSS, belonging to phage type PT20, ATASCSS associated with strains DT104L/ad and ATATSS for isolates that were not type able. The PFGE patterns were different for each Salmonella serotype. All strains were negative for the virulence gene spvR. Conclusions: To our knowledge, this is the first molecular characterization of Salmonella in food and humans from Morocco. Comparison of molecular techniques for differentiating between human and food isolates of Salmonella in north of Morocco shows that ERIC typing and PFGE were more discriminating than the other techniques used in this study

Changing patterns of Vibrio cholerae in sevagram between 1990 and 2005.

PURPOSE: A retrospective analysis was done to note changes in prevalence, distribution of biotypes, serotypes, antibiotic susceptibility patterns and phage types of Vibrio cholerae isolated in Mahatma Gandhi Institute of Medical Sciences, Sevagram over a period of 16 years. METHODS: A total of 535 strains of V. cholerae were isolated from 10,406 stool samples and rectal swabs from January 1990 to December 2005. These comprised of serogroups O1 - 427 (79.89%), O139 - 86 (16.07%) and non O1, non O139 - 22 (4.11%). No classical V. cholerae was isolated. RESULTS: Vibrio cholerae serogroup O1 serotype Ogawa was the predominant isolate till 1992. During 1993, serogroup O139 became the main isolate; however, it completely disappeared during 1995-1996 only to reappear in 1997. Serotype Inaba in our area was conspicuous by its absence with only two strains being isolated till June 1999, but during July-December 1999, 11 out of 15 V. cholerae O1 isolates were El Tor Inaba. T4 was the predominant phage type till 1990, T2 during 1991-1994 and T27 (as per the new scheme) thereafter. Resistance to tetracycline varied between 2 and 17% for V. cholerae O1. CONCLUSIONS: The paper reports on the changing epidemiological markers of V. cholerae isolated from a rural hospital over a period of 16 years.

Molecular typing of isolates from two dysentery outbreaks in Chengdu, through pulsed field gel electrophoresis technology / 中华流行病学杂志

<p><b>OBJECTIVE</b>Using pulsed field gel electrophoresis (PFGE) and polymerase chain reaction (PCR) typing to analyze strains isolated from two outbreaks caused by Shigella sonnei and to trace the source of infection.</p><p><b>METHODS</b>Virulence genes ipaH and ial were detected by PCR and PFGE was used to subtype the isolates. Patterns were compared, using the software BioNumerics.</p><p><b>RESULTS</b>Within the 54 isolates, all were ipaH positive with 48 as ial positive. Strains from the Chongzhou outbreak were clustered into 4 PFGE patterns, with the predominant pattern accounted for 72% of the analyzed strains. The pattern of strains isolated from the cold pork with sauce was identical to the predominant pattern. The strains from Dayi outbreak were clustered into 8 PFGE patterns and the predominant pattern accounted for 56% of the test strains.</p><p><b>CONCLUSION</b>Strains from the two outbreaks were quite different and the 'cold pork with sauce' seemed to be the major source of infection, causing the outbreak of diarrhea in Chongzhou. The sources of infection of the Dayi outbreak might be complicated whereas PFGE showed a discriminatory and reproducible laboratory tool in the epidemiologic investigation on outbreaks of diarrhea.</p>

Caracterización de dos brotes de fiebre tifoidea en Apartadó, Antioquia, 2005 / Characterization of two typhoid fever outbreaks in Apartadó, Antioquia, 2005

Introducción. La caracterización de los brotes de fiebre tifoidea es importante epidemiológicamente, debido a que esto permite la búsqueda de la fuente y el desarrollo de medidas de control. Objetivo. Describir un brote de fiebre tifoidea en el municipio de Apartadó y caracterizar fenotípica y genotípicamente los aislamientos de Salmonella Typhi relacionados con él. Materiales y métodos. Se estudiaron 44 pacientes, a 15 de ellos se les tomaron muestras para hemocultivos y a 7, muestras para coprocultivos. Los aislamientos bacterianos se estudiaron con pruebas bioquímicas y serotipificación y se determinó el perfil de susceptibilidad a antibióticos. Los aislamientos se evaluaron fenotípicamente por reacción en cadena de la polimerasa para los genes hilA, invA e IS- 200, y por electroforesis en campo pulsado con XbaI. Se estudiaron ocho muestras de agua asociadas al brote por reacción en cadena de la polimerasa y cultivo para la búsqueda de Salmonella. Resultados. A 15/44 pacientes se les confirmó el diagnóstico clínico de fiebre tifoidea, a 13 por hemocultivos y a 2 por coprocultivos positivos para S. Typhi. Todos los aislamientos de S. Typhi fueron sensibles a los antibióticos probados. La reacción en cadena de la polimerasa confirmó la presencia de los genes hilA y invA e IS-200 en todos los aislamientos estudiados. La electroforesis en campo pulsado agrupó 10 aislamientos en el patrón COINJPP.X01.0035, tres en el patrón COINJPPX01.0002, uno COINJPP.X01.0012 y uno COINJPPX01.0037. El estudio de aguas fue negativo para Salmonella spp. Conclusiones. La electroforesis en campo pulsado estableció la presencia de dos brotes, que inicialmente, por epidemiología y pruebas fenotípicas del patógeno, habían sido descritos como uno solo. Además, permitió diferenciar dos aislamientos de origen clonal diferente, que indicaron casos aislados. No se pudo corroborar la fuente de infección en el agua.

Introduction. The characterization of typhoid fever outbreaks is important because it is necessary to find the source of the infection and development control measures. Objective. A typhoid fever outbreak is described from Apartadó and the Salmonella Typhi isolates characterized by phenotypic and genotypic methods. Materials and methods. From 44 patients, 15 blood cultures and 7 stools cultures were recovered. Phenotypic identification of isolates was done by biochemical and serological tests, and antibiotic susceptibility was tested. Genes hilA, invA and the IS200 marker were evaluated by polymerase chain reaction; pulsed field gel electrophoresis was used for the XbaI gene. Eight water samples were examined by polymerase chain reaction and culture methods in order to isolate Salmonella spp. Results. Fifteen patients were confirmed for typhoid fever, 13 by blood cultures and two by stools cultures. All S. Typhi isolates were susceptible to the antimicrobials tested. The presence of hilA, invA and IS200 were confirmed by polymerase chain reaction in all isolates. The pulsed field gel electrophoresis method grouped 10 isolates in COINJPP.X01.0035 pattern, three in COINJPPX01.0002, one in COINJPP.X01.0012 and one in COINJPPX01.0037. Water isolates were negatives for Salmonella spp. Conclusions. Pulsed field gel electrophoresis discriminated the isolates in two outbreaks. Initially the cases were described as only one outbreak, by epidemiological criteria and phenotypic test. Additionally two isolates with different clonal origin were discriminated, indicating that they were unrelated to the other cases. It was not possible to confirm the infection source from water samples.

Occurrence, significance & molecular epidemiology of cholera outbreaks in West Bengal.

BACKGROUND & OBJECTIVE: Diarrhoeal disease outbreaks are causes of major public health emergencies in India. We carried out investigation of two cholera outbreaks, for identification, antimicrobial susceptibility testing, phage typing and molecular characterization of isolated Vibrio cholerae O1, and to suggest prevention and control measures. METHODS: A total of 22 rectal swabs and 20 stool samples were collected from the two outbreak sites. The V. cholerae isolates were serotyped and antimicrobial susceptibility determined. Pulsed- field gel electrophoresis (PFGE) was performed to identify the clonality of the V. cholerae strains which elucidated better understanding of the epidemiology of the cholera outbreaks. RESULTS: Both the outbreaks were caused by V. cholerae O1 (one was caused by serotype Ogawa and the other by serotype Inaba). Clinically the cases presented with profuse watery diarrhoea and dehydration. All the tested V. cholerae isolates were sensitive to tetracycline, gentamycin and azithromycin but resistance for ampicillin, co-trimoxazole, nalidixic acid, and furazolidone. PFGE pattern of the isolates from the two outbreaks revealed that they were clonal in origin. Stoppage of the source of water contamination and chlorination of drinking water resulted in terminating the two outbreaks. INTERPRETATION & CONCLUSION: The two diarrhoeal outbreaks were caused by V. cholerae O1 (Inaba/Ogawa). Such outbreaks are frequently seen in cholera endemic areas in many parts of the world. Vaccination is an attractive disease (cholera) prevention strategy although long-term measures like improvement of sanitation and personal hygiene, and provision of safe water supply are important, but require time and are expensive.

Antimicrobial susceptibility patterns and phage types of Salmonella typhi from Vietnam.

A retrospective study of the patterns of antimicrobial susceptibility and phage types of 111 Salmonella typhi strains isolated in 1996 from Vietnam was carried out. The strains were tested for susceptibility to chloramphenicol, ampicillin, tetracycline, trimethoprim-sulfamethoxazole, nalidixic acid, ceftazidime, ceftriaxone and ciprofloxacin. Simultaneous resistance to chloramphenicol, ampicillin, tetracycline and trimethoprim-sulfamethoxazole were present in 84 strains (75.7%). Nalidixic acid resistance was only observed in 2 multidrug-resistant strains (1.8%). Twenty-one strains (18.9%) were completely susceptible to all drugs tested. All 111 strains were susceptible to ceftazidime, ceftriaxone and cipropfloxacin. The MIC values for chloramphenicol, ampicillin and trimethoprim-sulfamethoxazole corresponded with the results by disk diffusion method. On Vi phage-typing, 5 different phage types (28, A, D1, E1 and M1) were found in 12 strains (10.8%). However, most S. typhi strains were indistinguishable by this typing technique because they were degraded Vi-positive or untypeable Vi-positive strains (35.1% and 54.1%, respectively). There were no correlations between antimicrobial resistance patterns and phage types in the tested S. typhi strains in this study.

Phage typing, biotyping & antimicrobial resistance profile of Salmonella enterica serotype Typhi from Kolkata.

BACKGROUND & OBJECTIVE: Kolkata and its suburbs in eastern India are known to be endemic for typhoid fever. The objective of this study was to determine phage types, biotypes and antimicrobial resistance patterns of Salmonella enterica serotype Typhi isolated during the period 2003-2005 from a prospective surveillance for typhoid fever in two urban slums in Kolkata. METHODS: A total of 195 Salmonella enterica serotype Typhi isolated from blood cultures were phage typed, biotyped and tested for their antimicrobial susceptibility profile. RESULTS: Phage type E1 was the most common (60.3%) followed by phage type A among five phage types identified. Biotype I (95%) was predominant, 28 isolates were multidrug resistant (MDR) and most of the MDR strains belonged to phage type E1 and biotype I. INTERPRETATION & CONCLUSION: A single phage type and biotype were prevalent among the Salmonella enterica serotype Typhi isolates studied from Kolkata, India.

A study of phage based diagnostic technique for tuberculosis.

BACKGROUND: Tuberculosis (TB) is a leading infectious disease in India.Diagnosis of TB has always been a problem due to slow rate of growth of Mycobacterium tuberculosis. In this study we have compared the conventional tools for diagnosis of TB with the new Fast Plaque TB TM MATERIAL AND METHODS: Two hundred and twelve clinically suspected cases of TB were enrolled for the study. Three consecutive early morning sputum samples were collected from each patient. Sputum smears were examined after staining with ZN stain and the sputum samples were later subjected to culture and phage assay. RESULTS: It was seen from the study that out of the total 212 cases, 106 were phage positive and 106 were phage negative. Sensitivity of the phage test with respect to AFB smear is 94.34% and specificity of the phage test is 93.88%. A total of 120 specimens grew on LJ media, of which 112 were Mycobacterium tuberculosis, 2 were Mycobacterium Kansasii, 4 were Mycobacterium avium complex and 2 grew Mycobacteriumfortuitum group. Out of these 120 specimens which grew on LJ, 104 were also positive for phage assay. All the 8 Non-Tubercular Mycobacteria were negative by the Fast Plaque Assay. Out of the 92 which were negative on LJ, 2 were positive by phage assay. Sensitivity and specificity of phage assay with respect to growth on LJ was 92.86% and 97.83% respectively. CONCLUSION: The study showed that phage assay is a rapid, reliable and cost effective method in diagnosing pulmonary tuberculosis from clinical samples.

Identification and molecular study on vibrio cholerae in sea products / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the serologic type, phage-biotype and toxic factor of Vibrio cholerae isolated from different sea products, analyze the relation between the Vibrio cholerae in sea products and cholera epidemiology, and provide references for forecasting cholera epidemic situation and drawing out a preventing plan.</p><p><b>METHOD</b>The biotype of strains isolated was analyzed by using type and phage-biotype serological methods. The toxic gene was detected by PCR.</p><p><b>RESULTS</b>The constituent ratio of V. cholerae O139, Ogawa and Inaba were, respectively, 48.44%, 20.31% and 31.25% in 64 strains of V. cholerae. The result of phage-biotype showed that the 26 strains of V. cholerae O1 were all non-epidemic strains. The result of toxic gene detecting showed that positive rate of V. cholerae O139 was higher than those of Ogawa and Inaba.</p><p><b>CONCLUSION</b>The positive rate of toxic gene in V. cholerae O139 was high and the V. cholerae O139 was mainly in turtle, breed aquatics water and crustacean, so these sea products were the important sectors in cholera prevention and control.</p>