Caracterización de agentes bacterianos aislados en brotes de enfermedades transmitidas por alimentos / Characterization of bacterial agents isolated in diseases outbreaks transmitted by foods

Introducción: Las enfermedades transmitidas por alimentos se producen por ingestión de un alimento, incluido el agua, que puede estar contaminado por diversos agentes. Objetivo: Caracterizar los agentes bacterianos aislados en brotes de enfermedades transmitidas por alimentos. Métodos: Se realizó un estudio observacional, descriptivo y transversal de 100,0 % de los brotes de enfermedades transmitidas por alimentos en la provincia de Santiago de Cuba, desde enero de 2018 hasta diciembre de 2019, para lo cual se seleccionaron muestras de alimentos y heces fecales. La caracterización de las bacterias aisladas se basó en los resultados del crecimiento y otras pruebas bioquímicas-metabólicas. Se utilizaron resultados del aislamiento y confirmación de los agentes identificados en cada uno de los brotes a partir de las muestras antes citadas. Entre las variables analizadas figuraron: número de brotes, muestras de alimentos, de heces fecales y resultados de pruebas bioquímicas y metabólicas. Resultados: Se obtuvo un aislamiento de agentes bacterianos en 100,0 % de las muestras de alimentos. Hubo una mayor frecuencia de bacterias Gram negativas (82,0 %) y la menor correspondió a microorganismos Gram positivos (18,0 %). La Salmonella D fue el microorganismo más frecuente. Conclusiones: Este resultado representa un instrumento para el diagnóstico etiológico de los brotes de enfermedades transmitidas por alimentos en Santiago de Cuba.

Introduction: Diseases transmitted by foods are produced due to ingestion of a food, including water that can be contaminated by diverse agents. Objective: To characterize the bacterial agents isolated in diseases outbreaks transmitted by foods. Methods: An observational, descriptive and cross-sectional study of 100.0 % of the diseases outbreaks transmitted by foods in Santiago de Cuba, from January, 2018 to December, 2019 was carried out, for which samples of foods and stools were selected. The characterization of the isolated bacterias was based on the results of growth and other biochemical-metabolic tests. Results of the isolation and confirmation of agents identified in each one of the outbreaks from the samples mentioned above were used. Among the analyzed variables we can mention: number of outbreaks, samples of foods, samples of stools and results of biochemical and metabolic tests. Results: An isolation of bacterial agents was obtained in 100.0 % of foods samples. There was a higher frequency of Gram negative bacterias (82.0 %) and the lower corresponded to Gram positive microorganisms (18.0 %). Salmonella D was the most frequent microorganism. Conclusions: This result represents an instrument for the etiological diagnosis of diseases outbreaks transmitted by foods in Santiago de Cuba.

Analyzing Patterns for Stool Culture Requests by Physicians to Improve Quality

Although international clinical guidelines generally recommend bacterial stool cultures for patients with acute diarrhea, stool cultures are frequently being requested by physicians regardless of the likelihood of a bacterial infection. This study was conducted to improve the practice of requesting stool cultures by analyzing patterns for stool culture requests by physicians. We retrospectively reviewed 235 stool cultures of patients who visited Gyeongsang National University Hospital from January to February 2017. We analyzed the period of time after which the stool culture was requested after admission, stool characteristics, wet smear, and concomitant tests performed. 38.7% of stool culture requests were made within 3 days of admission. Stool form analysis showed that 36.6% of stools were watery and loose, and 18.8% were firm. Furthermore, >20 leukocytes per high-power field were found only in 0.4% of the wet smears. Among the stool culture requests, 78.7% were prescribed Clostridium difficile culture or toxin tests at the same time. In addition, 13.6% were prescribed diarrhea-causing viral tests as well. Only stool cultures were requested in 10.2% of the cases. Physicians rarely ensure that the adequate criteria are met when requesting for stool cultures. It is necessary to decrease unnecessary diagnostic practices to maintain the quality of care by establishing reliable rejection criteria and the physicians have valid reasons for requesting stool cultures.

Positive stool culture could predict the clinical outcomes of haploidentical hematopoietic stem cell transplantation / 医学前沿

We aimed to identify the effect of positive stool cultures (PSCs) on the clinical outcomes of patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) (n = 332). PSCs were observed in 61 patients (PSC group, 18.4%). Enterobacteriaceae in stool specimens was associated with a higher risk of bloodstream infection, and Candida in stool specimens was related to a higher risk of platelet engraftment failure. The cumulative incidence of infection-related mortality 1 year after haplo-HSCT in the PSC group was higher than that of the patients who showed persistently negative stool cultures (NSC group; 19.2% vs. 8.9%, P = 0.017). The probabilities of overall survival (71.4% vs. 83.8%, P = 0.031) and disease-free survival (69.6% vs. 81.0%, P = 0.048) 1 year after haplo-HSCT for the PSC group were significantly lower than those for the NSC group, particularly for patients who had Candida in their stool specimens. In multivariate analysis, Candida in stool specimens significantly increased the risk of mortality and was associated with poorer survival. Our results showed that PSC influenced the clinical outcomes after haplo-HSCT, particularly those who had Candida in their stool specimens.

Campylobacter Data in Childhood from a University Hospital.

Background and Objectives: Due to underdiagnosis because of the technical difficulties plus inadequacy of laboratories, actual incidence of campylobacteriosis may substantially be greater than the reported incidence in many countries including Turkey. The purpose of this study was to evaluate and emphasize the diagnostic methods of campylobacteriosis, and the clinical and laboratory data of children with Campylobacterial gastroenteritis. Methods: This study was conducted in Yeditepe University Hospital, Istanbul, Turkey. Clinical (demographical data, symptoms and findings) and laboratory (stool microscopy, rapid antigen tests, culture, and multiplex PCR and blood test results) variables of children with Campylobacter infection between January 2010 and October 2012 were evaluated retrospectively from the hospital database. Results: Out of 1275 stool cultures, Campylobacter spp. was detected in 90 of them (7%). The diagnosis was made by positive stool culture (n = 87) and/or multiplex polymerase chain reaction (PCR) test (n = 8, whereas 3 of them were culture negative). The distribution of Campylobacter isolates were; C. jejuni (85.5%), C. upsaliensis (8.9%), C. coli (1.1%), and others (4.5%). The presenting symptoms were diarrhea (100%), fever (68.9%), abdominal pain (34.4%), dehydration (27.8%), vomiting (25.5%), bloody diarrhea (5.6%), and convulsion (1%). Hospitalization was required in 25.5% of patients. Conclusions: Although stool culture is a reference method in diagnosis, the PCR test can be used in culture negative patients with clinical manifestations. Diarrhea, fever, abdominal pain, and vomiting were most commonly encountered symptoms whereas bloody diarrhea and convulsion were rarely seen in campylobacteriosis. Also antibiotherapy and hospitalisation were not commonly required.

A Case of Simultaneous Isolation of Vibrio parahaemolyticus and Vibrio alginolyticus / 대한임상미생물학회지

V.parahaemolyticus or V.alginolyticus infections are usually associated with consumption of raw or undercooked shellfish, contaminated food, and exposure of wounds to warm seawater. V.parahaemolyticus causes gastroenteritis(the most common syndrome), wound infections, and septicemia. V alginolyticus occasionally causes extraintestinal infections in humans. so far, the authors have not found the report of V.parahaemolyticus and V.alginolyticus isolation from a patient. So, we report a case of concurrent isolation of V.parahaemolyticus and V.alginolyticus from a patient who had a history of intestinal diarrhea and vomiting.

A Case of Simultaneous Isolation of Vibrio parahaemolyticus and Vibrio alginolyticus / 대한임상미생물학회지

V.parahaemolyticus or V.alginolyticus infections are usually associated with consumption of raw or undercooked shellfish, contaminated food, and exposure of wounds to warm seawater. V.parahaemolyticus causes gastroenteritis(the most common syndrome), wound infections, and septicemia. V alginolyticus occasionally causes extraintestinal infections in humans. so far, the authors have not found the report of V.parahaemolyticus and V.alginolyticus isolation from a patient. So, we report a case of concurrent isolation of V.parahaemolyticus and V.alginolyticus from a patient who had a history of intestinal diarrhea and vomiting.

Usefulness of selenite F enrichment broth for the isolation of Salmonella from stool / 대한임상병리학회지

BACKGROUND: Stool culture for enteric pathogens constitutes a significant portion of the workload in clinical microbiology. Several reports recommended that selenite enrichment have been used only in stool cultures from suspected carriers, during outbreaks, and other special circumstances for cost-effectiveness. We evaluated the usefulness of selenite F enrichment for the isolation of Salmonella in routine stool cultures. METHODS: Stool specimens submitted from March to October, 1999 were inoculated onto MacConkey(Mac) agar and Salmonella-Shiegella(SS) agar and into Selenite F(SF) enrichment broth. After overnight incubation, the SF broth was subcultured onto a second SS agar. RESULTS: Total 45 strains of Salmonella spp. were recovered from 1,338 stool specimens and Shiegella or other enteric pathogens were not recovered. Twenty out of the forty-five Salmonella spp.(44%) were recovered on Mac agar and 33 of 45 Salmonella spp.(73%) on SS agar, 45 out of 45 Salmonella spp.(100%) after SF enrichment and 35 of 45 Salmonella spp.(78%) on Mac and/or SS agar. Ten Salmonella spp. were recovered only after SF enrichment, but no Salmonella spp. were recovered only on the primary Mac agar or SS agar. After SF enrichment, Salmonella spp. grew more purely and heavily than on the primary medium. CONCLUSIONS: These results suggest that SF enrichment is necessary to routine stool cultures and the elimination of the primary Mac or SS agar is cost-effective than the elimination of SF enrichment.

Nalidixic acid in the management of diarrhea enteritis in infants and children (a report on hospital cases)

Nalidixic acid was given orally to 50 infants and children, who were hospitalized for diarrhea, ranging in age from a few days to 9 years in a dose of 25 mg. per lb. per day divided into 3 or 4 doses for one week. These patients had not received an antimicrobial therapy prior to the administration of nalidixic acid. However, fluid therapy and symptomatic measures were given as indicatedAn initial blood count, stool examination and stool culture were done on each patient. Sensitivity tests followed isolation of pathogenic microorganisms. Follow-up microscopic stool examinations and cultures were done 3 and 5 days after therapy and again a week laterIn this group of 50 patients under study the following observations are enumerated: - 96% were moderately ill- A aerogenes (in 78% of the cases) and pathogenic E. Coli (in 76% of the cases) were the predominating microorganisms, although a combination of more than one organism was commonly noted- These organisms were satisfactorily sensitive to nalidixic acid (77% to 86.8% of the cases)- The clinical manifestation were observed to improve within 3 to 7 days in 94% of the cases- Similarly the microscopic stool examinations cleared up in 96% of the cases- The drug was acceptable orally so that this presented no problem- No untoward effects were noted in the course of therapy nor a week later. (Summary and Conclusions)

Comparison of Isolation rate of the Pathogenic Microorganisms According to Stool Culture Methods / 대한임상미생물학회지

BACKGROUND: In developed countries, food-born diseases have decreased and hospital laboratory have taken more simple method rather than complex enrichment-selective methods. But detection rate of pathogenic bacteria in stool culture was not so high. METHODS: We mixed 4 pathogenic bacteria (S. typhi, S. flexneri, V. cholerae and Y. enterocolitica) with 3 stool specimens from healthy persons (for Y. enterocolitica, 5 specimens) and innoculated directly or after enrichment (105 bacteria/plate). After proper incubation, we counted suspected colonies and calculated true positive rate after identification of each colonies. RESULTS: For S. typhi, in the case of direct innoculation on the MacConkey, XLD and SS agar, positive rate of selected colonies were below 36.6%. After enrichment in SF broth for 8 hours, the rate were 80.0%, 83.0% and 70.0% respectively. For S. flexneri, the rates were 86.7%, 100%, 93.3% in direct innoculation, and were highest after enrichment in GN broth for two hours (93.3% in MacConkey and 100.0% in both XLD and SS agar). For V. cholerae, inspite of screening by catalase and oxidase tests, positive rate of selected colonies were 0% (0/7 colonies) in direct innoculation on the MacConkey. After enrichment in APW about 1 day and on TCBS agar, the rate were 100%. For Y. enterocolitica, after incubation at room temperature for 2 days, most selected colonies were Y. enterocolitica on CIN media. CONCLUSION: For more efficient detection of pathogenic bacteria in stool culture, combination of direct innoculation on MacConkey agar and on one or two selective media after proper enrichment process, should be considered.

Yersinia pseudotuberculosis Infection Confirmed by Stool Culture in Children

PURPOSE: The clinical significance of Y. pseudotuberculosis infection has recently recognizd in various part of the world, because it can cause a wide range of clinical problems such as mesenteric lymphadenitis, septicemia, reactive arthritis, terminal ileitis, erythema nodosum, and a cute renal failure. We have experienced 19 children with Y. pseudotuberculosis infection confirmed by stool culture. Our aim in this study was to evaluate clinical charactieristics, age and sex distribution, and source of infection. METHODS: Stools were inoculated on CIN(Cefsulodin-Irgasan-Novobiosin) agar (Difco, USA) and incubated for 48hr at 22 degrees C for isolation of Y. pseudotuberculosis. API 20E and VITEC were used for identification of the isolates. The antimicrobial sensitivity tests were performed by GN S(gram negative sensitive) card. Clinical characteristics were analyzed retrospectively. RESULTS: Retrospective analysis of 19 children with Y. pseudotuberculosis infection who visited our hospital between Jun.1993 and Dec.1993 was performed. The most prevalent age group was 6 to 8 years(42%) and monthly distribution showed November, December, June, and July in order of frequency, respectively. The common symptoms and signs were fever(100%), abdominal pain(100%), rash(74%), s trawberry tongue(53%), vomiting(53%), diarrhea(37%), and desquamation(32%), respectively. Four cases among 9 cases showed multiple mesenteric lymph node enlargements on the abdominal ultrasonogaphy. Serogroups of the isolates from stool specimens were type 5(15/19, 79%), and type 4(4/19, 21%), respectively. Y. pseudotuberculosis was also isolated from 3 samples of untreated drinking water which was thought to be the source of infection. There were no resistance strains against Amikacin, Carbenidlin, Gentamicin, and Trimethoprim/Sulfamethoxazole in the antibiotic susceptibility tests. CONCLUSIONS: In this study, the antibiotic susceptibility against Y. pseudotuberculosis was excellent, although the clinical characteristics were various. We have found that untreated drinking water was an important source of this infection. Further epidemiologic study for this infection should be needed.