***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The efficacy of ciprofloxacin was compared with that of trimethoprim-sulfamethoxazole in a placebo-controlled trial of the 5-day treatment of acute diarrhea among 181 adults recently arrived in Guadalajara , Mexico . Both antimicrobial agents were significantly ( p less than 0.0001 ) more efficacious than placebo in the treatment of diarrhea , with the average duration of diarrhea being 29 , 20 , and 81 hours , respectively , in the ciprofloxacin , trimethoprim-sulfamethoxazole , and placebo treatment groups . The antimicrobial agents were also more efficacious than placebo in treating diarrhea caused by enterotoxigenic Escherichia coli , invasive enteropathogens , and unknown pathogens . Both antimicrobials were effective in treating mild-to-moderate and moderate-to-severe disease , and both were well tolerated .  Ciprofloxacin appears to be a logical alternative to trimethoprim-sulfamethoxazole in the initial treatment of acute travelers ' diarrhea In a r and omized double-blind study , Swiss adults traveling to tropical countries for 12 to 28 days took a solid formulation of bismuth subsalicylate ( 1.05 or 2.1 g/day on a twice-daily regimen ) or placebo .  Efficacy was evaluated in 231 volunteers .  Diarrheal incidence was reduced by 41 % in persons taking the high dose ( P = 0.007 ) and by 35 % in those taking the low dose ( P = 0.03 ) with excellent compliance . No serious adverse reactions occurred , but objectionable taste , constipation , and nausea were seen more frequently with active medication ( P = 0.04 ) . Twenty patients provided stool sample s : no bacteria were detected in the 8 volunteers who were on active medication , but various bacteria were found in 5 of the 12 patients who had taken placebo ( P = 0.04 ) Enterotoxigenic E. coli ( ETEC ) are an important cause of diarrhea in developing countries , especially among indigenous children and travelers . In this r and omized , double-blind , placebo-controlled trial , a live , attenuated CS1/CS3 ETEC strain , PTL-003 , was tested as a potential vaccine strain . Thirty-three subjects drank buffered solutions containing either PTL-003 or placebo on Days 0 and 10 and were challenged with virulent CS1/CS3 ETEC strain E24377A on Day 28 . The vaccine did not protect against moderate to severe ETEC illness ( the primary endpoint ) , but it did prime subjects for a rapid antibody response to CS1 and CS3 after challenge , suggesting that a dose of vaccine on Day 28 might improve the immune response to the vaccine . Higher serum anti-CS3 IgA titers at the time of challenge correlated with less severe diarrheal illness Orally administered bovine immunoglobulins with specific activity against colonization factors of enterotoxigenic Escherichia coli ( ETEC ) could provide passive protection against ETEC challenge in volunteers . Twenty healthy adult volunteers ingested either a placebo or a partially enteric-coated preparation of bovine immunoglobulins with activity against the colonization factor antigens CFA/I , CS3 , and CS6 and then were challenged with ETEC strain E24377A ( CS1 + , CS3 + ) administered with a st and ard meal . There was no difference in the incidence or severity of diarrhea among the 10 volunteers who received the bovine immunoglobulins and the 10 who received placebo . Either the specificity or titer of anti-colonization factor antibodies or the formulation of antibodies in this product was not adequate to provide passive protection against ETEC challenge To determine the role of Escherichia coli heat-stable enterotoxin ( ST ) as a virulence factor in human diarrhea , a strain that elaborates only ST ( E. coli 214 - 4 ) was fed to free-living volunteers in doses of 10(6 ) , 10(8 ) , and 10(10 ) organisms . Short-lived ( 1 day ) mild illness consisting of abdominal cramps with vomiting or diarrhea occurred in three of five individuals fed 10(8 ) . Typical travelers ' diarrhea ( loose stools , abdominal cramps , and low- grade fever for 2 to 3 days ) was seen in four of five volunteers given 10(10 ) ; two had brief cholera-like purging of rice-water stools . Despite fever , there was no evidence of mucosal invasion . E. coli 214 - 4 became the predominant coliform in stools ; coproculture isolates were uniformly negative for heat-labile enterotoxin ( LT ) , whereas most produced ST . Ten of 13 individuals developed rises in antibody to somatic E. coli antigen , and none had rises in LT antitoxin . E. coli that elaborate only ST can cause diarrheal disease in adults Vaccine regimens which mimic actual infection with bacterial enteropathogens should offer the best opportunity for successful long-term immunoprotection against diarrheal disease caused by enterotoxigenic Escherichia coli ( ETEC ) or Vibrio cholerae . Based on this principle , we design ed and tested an oral whole cell anti-ETEC vaccine consisting of intact cells of ETEC strain H-10407 ( ST+LT+ ; O78:H11:CFA/I ) which were rendered incapable of replication by treatment with a potent DNA endonuclease , colicin E2 . Young healthy volunteers were administered two oral doses of either placebo or approx . 3 X 10(10 ) vaccine cells . In a double-blind study , 9 of 10 vaccinees responded with an increase in CFA/I-specific intestinal IgA antibody , determined as percent of total IgA. Challenge with virulent strain H-10407 ( 5 X 10(9 ) living cells ) produced diarrhea in 8 of 9 ( 89 % ) of the placebo-treated volunteers and in 2 of 10 ( 20 % ) of the vaccinees . Thus , the colicin E2-killed whole cell vaccine afforded both a significant intestinal immune response and significant protection against challenge with the virulent organism . The data presented here suggest that for this vaccine preparation an intestinal anti-CFA/I IgA response is a good indicator of a protective immune response , which most likely involves antibody responses to a number of antigens in addition to CFA/I. We conclude that the colicin E2 method for preparing an oral anti-ETEC vaccine merits further study and that this method may also be applicable to other enteropathogens BACKGROUND An enterotoxigenic Escherichia coli ( ETEC ) vaccine could reduce diarrhea among children in developing countries and travelers to these countries . The heat-labile toxin ( LT ) of ETEC is immunogenic but too toxic for oral or nasal vaccines . METHODS In a double-blind , placebo-controlled trial , 59 adults were r and omized to receive 50 microg of LT or placebo in a patch applied to alternating arms on days 0 , 21 , and 42 . On day 56 , 27 vaccinees and 20 controls were challenged orally with 6x10(8 ) cfu of LT+/ST+ ETEC . RESULTS 100 and 97 % of vaccinees had 4-fold increases in anti-LT IgG and IgA , and 100 and 90 % developed IgG- and IgA-antibody-secreting cell responses . The study did not meet the primary endpoint : 82 % of vaccinees and 75 % of controls had moderate to severe ETEC illness . However , vaccinees with ETEC illness had lower numbers ( 6.8 versus 9.7 , p=0.04 ) and weights of loose stools ( 840 g versus 1147 g , p<0.05 ) , a decreased need for intravenous fluids ( 14 % versus 40 % , p=0.03 ) and a delayed onset of diarrhea ( 30 h versus 22 h , p=0.01 ) . CONCLUSIONS Transcutaneous LT vaccination induced anti-toxin immune responses that did not prevent but mitigated illness following a high-dose challenge with a virulent LT+/ST+ ETEC strain BACKGROUND A robust human challenge model for Campylobacter jejuni is an important tool for the evaluation of c and i date vaccines . The previously established model conveys a potential risk of Guillain-Barré syndrome attributable to lipooligosaccharide ganglioside mimicry . This work establishes a new C. jejuni human challenge model that uses a strain ( CG8421 ) without ganglioside mimicry and that applies Campylobacter-specific cellular immunity screening to achieve high attack rates at lower inoculum doses . METHODS Healthy Campylobacter-naive adults participated in an open-label challenge trial . Participants were dosed with C. jejuni CG8421 and followed as in patients . Pattern of illness , bacterial shedding , and immunologic responses were determined . RESULTS Following screening , 23 subjects received 1 X 10(6 ) or 1 X 10(5 ) colony-forming units of C. jejuni , with attack rates ( percentage of patients who became ill ) of 100 % ( 1 X 10(6 ) colony-forming units ) or 93 % ( 1 X 10(5 ) colony-forming units ) . Every subject shed CG8421 ; the median time to diarrhea onset was 72.3 h ( interquartile range , 53.9 - 99.9 h ) . Symptoms included abdominal cramps ( 74 % ) , nausea ( 65 % ) , and fever ( 39 % ) . No major safety concerns occurred , including bacteremia , hypotension , or postinfectious sequelae . Unexpectedly , recrudescent infection occurred in 2 subjects ( 1 subject without Campylobacter-specific adaptive immune responses and 1 with azithromycin resistance acquired in vivo ) ; both infections cleared after receipt of additional antibiotics . Cumulative Campylobacter-specific immune responses were as follows : serologic response occurred in 87 % ( immunoglobulin [ Ig ] A ) and 48 % ( IgG ) of subjects , in vitro interferon-gamma production occurred in 91 % of subjects , and 96 % of subjects had IgA antibody-secreting cells and fecal IgA detected . CONCLUSIONS The C. jejuni CG8421 challenge model provides a safe and effective tool , without the risk of Guillain-Barré syndrome . The model demonstrates high attack rates after lower doses of challenge inoculum , provides further underst and ing of immunologic responses , and permits future investigation of c and i date Campylobacter vaccines Enterotoxigenic Escherichia coli cause most traveler 's diarrhea in Third World countries . We tested bismuth subsalicylate as prophylactic therapy and as treatment for enterotoxigenic E. coli-induced  diarrhea . Thirty-two healthy hospitalized volunteers were challenged orally with enterotoxigenic E. coli , strain H10407 ( serotype 078:K80:H11 ) . Administration of 600-mg doses of bismuth subsalicylate or placebo was begun 8 h before bacterial challenge . Doses were taken at 8 h and 2 h before , and at 2 h and 4 h after , the E. coli challenge and were continued four times a day for 3 additional days . The maximum prophylactic bismuth subsalicylate dose was 9.6 g. Those experiencing diarrhea were rer and omized to receive bismuth subsalicylate or placebo , given as 300 mg every 30 min for a total of 2.4 g of bismuth subsalicylate , in eight doses . Diarrhea occurred in 9 of the 16 ( 56 % ) subjects receiving placebo and in 2 of the 15 ( 13 % ) subjects receiving bismuth subsalicylate , p less than 0.03 . This study confirms the effectiveness of bismuth subsalicylate in preventing traveler 's ( enterotoxigenic E. coli ) diarrhea , and shows that bismuth subsalicylate in other than liquid form is effective . Enterotoxigenic E. coli were recovered less frequently from those receiving bismuth subsalicylate than from those receiving placebo , suggesting that bismuth subsalicylate prevents diarrhea by reducing the number or multiplication of enterotoxigenic E. coli . In vitro studies revealed that bismuth subsalicylate and its components each were bactericidal at concentrations possibly attained during the clinical trial The development of a safe and effective vaccine against enterotoxigenic Escherichia coli ( ETEC ) would be useful for travellers and for young children in endemic areas . A feasibility study of an enteral ETEC vaccine prototype consisting of colonization factor antigen II ( CFA/II ) , containing two component antigens CS1 and CS3 , encapsulated in biodegradable polymer microspheres ( BPM ) 
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Additionally , the rate of output was different across strains .
The risk of diarrhea , abdominal cramps , nausea and headaches differed significantly by ETEC strain .
An increased risk of nausea , abdominal cramps and headaches was seen for females .
Baseline anti-LT IgG titers appeared to be associated with a decrease risk of diarrhea outcomes , a trend not seen with anti-LT IgA or seen consistently with anti-colonization factor antibodies .
Neither early antibiotic treatment nor diarrhea duration significantly affected the frequency or magnitude of serologic responses .