Objective:To compare the sensitivity and specificity of direct fecal smear microscopy,culture,and polymerase chain reaction in the detection of Blastocystis sp.in human stool.Methods:Human stool samples were collected...Objective:To compare the sensitivity and specificity of direct fecal smear microscopy,culture,and polymerase chain reaction in the detection of Blastocystis sp.in human stool.Methods:Human stool samples were collected from a community in San Isidro,Rodriguez,Rizal,Philippines.These samples were subjected to direct fecal smear microscopy,culture and polymerase chain reaction to detect the presence of Blastocystis sp.Results:Of the 110 stool samples collected,28(25%)were detected positive for the presence of Blastocystis sp.by two or more tests.Culture method detected the highest number of Blastocystis-positive stool samples(n=36),followed by PCR of DNA extracted from culture(n=26),PCR of DNA extracted from stool(n=10),and direct fecal smear(n=9).Compared to culture,the sensitivity of the other detection methods were 66.7%for PCR from culture and 19.4%for both PCR from stool and direct fecal smear.Specificity of the methods was high,with PCR from culture and direct fecal smear having97.3%,while PCR from stool at 95.9%.Conclusions:In this study,in vitro culture is the best method for detecting Blastocystis sp.in human stool samples.展开更多
A comparative study was performed to evaluate best practice culture media and enrichment broths for recovering Salmonella species from human stool samples. A total of 1297 human stools were collected and processed in ...A comparative study was performed to evaluate best practice culture media and enrichment broths for recovering Salmonella species from human stool samples. A total of 1297 human stools were collected and processed in this study. Evaluation of agar media was carried out by direct plating (DP), 1096 stool samples were inoculated on Modified Semisolid Rappaport-Vassiliadis (MSRV), Xylose-Lysine-Deoxycolate (XLD), MacConkey (MAC), and Hektoen Enteric (HE) agars. Evaluation of enrichment broths were carried out by enrichment all 1297 stool samples in Selenite broth (SB), Rappaport-Vassiliadis (RV) broth, and Buffered Peptone Water (BPW), followed by plating on MSRV, MAC, and HE agars. A total of 102 Salmonella-positive stools by DP, 85.3% (87/102) were recovered utilizing MSRV while recovery from XLD, MAC, and HE agars were 34.3% (35/102), 34.3% (35/102), and 29.4% (30/102) respectively. A total 299/1297 stools samples were Salmonella-positive on at least one plating medium after enrichment procedure were 77.3% (177/299) for SB, 86.0% (197/299) and 78.6% (180/299) for RV and BPW respectively. All Salmonella isolated in this study was nontyphi Salmonella. Presently, the data suggest that the use of MSRV over MAC, HE, and XLD agars for isolation nontyphi Salmonella species from human stools is more efficacious. Additionally, use of MSRV in combination with MAC and HE agars following enrichment in RV broth enhances recovery of nontyphi Salmonella species. However, RV broth is inhibitory to typhi Salmonella, thus use of MSRV medium in combination with MAC, HE or XLD agars in direct plating following enrichment in non-selective BPW is an alternate method for recovery of both typhi and nontyphi Salmonella species contaminated in human stool samples.展开更多
Campylobacter continues to be a major cause of bacteriamediated diarrheal diseases, both for Thai citizens and travelers to Thailand. For field epidemiological studies, appropriate methods for storage, intralaboratory...Campylobacter continues to be a major cause of bacteriamediated diarrheal diseases, both for Thai citizens and travelers to Thailand. For field epidemiological studies, appropriate methods for storage, intralaboratory transport of patients specimens and use of enrichment culture to isolate this organism is critical. Study A, represents patient stool specimens collected in Bangkok and processed for Campylobacter culture within three hours after collection. Study B, represents stool specimens collected from patients in northeast and Southern regions of Thailand in modified CaryBlair transport medium. These specimens were transported and processed for Campylobacter in Bangkok at varying intervals ranging from 1 to 7 days. Of 900 diarrheal samples examined in study A, a total of 158 were Campylobacter positive through culture. Of these, 145 and 141 isolates were cultured by direct plating and enrichment plating respectively (P = 0.5839). From 1,168 diarrheal stool samples examined in study B, 184 were positive for Campylobacter. Direct and enrichment plating resulted in 139 and 168 culture isolates;respectively (P = 0.0003). Samples from study B delayed in processing for 1 to 3 days, resulted in 46 and 50 isolated by direct and enrichment plating;respectively (P = 0.4545). However, among samples delayed in processing for 4 to 7 days, a total of 128 Campylobacter isolates were cultured, having cultured 93 and 118 isolates through direct and enrichment plating;respectively (P = 0.0003). At present these studies demonstrate that enrichment culture has no benefit when stool specimen collection and immediate processing occur and when there is a processing delay period of 1 - 3 days. However, enrichment culture was beneficial in instances where transport and processing was delayed 4 - 7 days.展开更多
基金supported by a research grant from the Office of the Vice-Chancellor for Research and Development,University of the Philippines-Diliman(Grant No.101007 PNSE)to W.L.R.and H.J.S
文摘Objective:To compare the sensitivity and specificity of direct fecal smear microscopy,culture,and polymerase chain reaction in the detection of Blastocystis sp.in human stool.Methods:Human stool samples were collected from a community in San Isidro,Rodriguez,Rizal,Philippines.These samples were subjected to direct fecal smear microscopy,culture and polymerase chain reaction to detect the presence of Blastocystis sp.Results:Of the 110 stool samples collected,28(25%)were detected positive for the presence of Blastocystis sp.by two or more tests.Culture method detected the highest number of Blastocystis-positive stool samples(n=36),followed by PCR of DNA extracted from culture(n=26),PCR of DNA extracted from stool(n=10),and direct fecal smear(n=9).Compared to culture,the sensitivity of the other detection methods were 66.7%for PCR from culture and 19.4%for both PCR from stool and direct fecal smear.Specificity of the methods was high,with PCR from culture and direct fecal smear having97.3%,while PCR from stool at 95.9%.Conclusions:In this study,in vitro culture is the best method for detecting Blastocystis sp.in human stool samples.
文摘A comparative study was performed to evaluate best practice culture media and enrichment broths for recovering Salmonella species from human stool samples. A total of 1297 human stools were collected and processed in this study. Evaluation of agar media was carried out by direct plating (DP), 1096 stool samples were inoculated on Modified Semisolid Rappaport-Vassiliadis (MSRV), Xylose-Lysine-Deoxycolate (XLD), MacConkey (MAC), and Hektoen Enteric (HE) agars. Evaluation of enrichment broths were carried out by enrichment all 1297 stool samples in Selenite broth (SB), Rappaport-Vassiliadis (RV) broth, and Buffered Peptone Water (BPW), followed by plating on MSRV, MAC, and HE agars. A total of 102 Salmonella-positive stools by DP, 85.3% (87/102) were recovered utilizing MSRV while recovery from XLD, MAC, and HE agars were 34.3% (35/102), 34.3% (35/102), and 29.4% (30/102) respectively. A total 299/1297 stools samples were Salmonella-positive on at least one plating medium after enrichment procedure were 77.3% (177/299) for SB, 86.0% (197/299) and 78.6% (180/299) for RV and BPW respectively. All Salmonella isolated in this study was nontyphi Salmonella. Presently, the data suggest that the use of MSRV over MAC, HE, and XLD agars for isolation nontyphi Salmonella species from human stools is more efficacious. Additionally, use of MSRV in combination with MAC and HE agars following enrichment in RV broth enhances recovery of nontyphi Salmonella species. However, RV broth is inhibitory to typhi Salmonella, thus use of MSRV medium in combination with MAC, HE or XLD agars in direct plating following enrichment in non-selective BPW is an alternate method for recovery of both typhi and nontyphi Salmonella species contaminated in human stool samples.
文摘Campylobacter continues to be a major cause of bacteriamediated diarrheal diseases, both for Thai citizens and travelers to Thailand. For field epidemiological studies, appropriate methods for storage, intralaboratory transport of patients specimens and use of enrichment culture to isolate this organism is critical. Study A, represents patient stool specimens collected in Bangkok and processed for Campylobacter culture within three hours after collection. Study B, represents stool specimens collected from patients in northeast and Southern regions of Thailand in modified CaryBlair transport medium. These specimens were transported and processed for Campylobacter in Bangkok at varying intervals ranging from 1 to 7 days. Of 900 diarrheal samples examined in study A, a total of 158 were Campylobacter positive through culture. Of these, 145 and 141 isolates were cultured by direct plating and enrichment plating respectively (P = 0.5839). From 1,168 diarrheal stool samples examined in study B, 184 were positive for Campylobacter. Direct and enrichment plating resulted in 139 and 168 culture isolates;respectively (P = 0.0003). Samples from study B delayed in processing for 1 to 3 days, resulted in 46 and 50 isolated by direct and enrichment plating;respectively (P = 0.4545). However, among samples delayed in processing for 4 to 7 days, a total of 128 Campylobacter isolates were cultured, having cultured 93 and 118 isolates through direct and enrichment plating;respectively (P = 0.0003). At present these studies demonstrate that enrichment culture has no benefit when stool specimen collection and immediate processing occur and when there is a processing delay period of 1 - 3 days. However, enrichment culture was beneficial in instances where transport and processing was delayed 4 - 7 days.
