摘要:

Escherichia coliinfection is one of the important causes of diarrheal diseases worldwide, particularly among infants and children. While local adherent enteroadherentE. coliare associated with infantile acute diarrhea, nontoxigenic aggregative adherentE. colihave become one of the major pathogens for persistent diarrhea. Novel bundle-forming pili in localized adherentE. coliand bundle-forming fimbriae in aggregative adherentE. colieach responsible for their particular adherence have been identified. EnterotoxigenicE. coliare involved in neonatal diarrhea and travelers' diarrhea. Although a family of colonization factors have been identified, in up to 25% of enterotoxigenicE. coli, colonization factors have not been determined. Verocytotoxin-producing enterohemorrhagicE. coliresponsible for bloody diarrhea and hemolytic-uremic syndrome are a family of serotypes producing a variety of verocytotoxins, and outbreaks are commonly related to contamination of meat as well as water. New technologies have resulted in improved methods for isolation and detection ofE. coliand new therapies are under investigation. These exciting new findings hold potential for substantially improved diagnosis, prevention, and treatment of intestinalE. coliinfections.

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The epidemiology of foodborne salmonellosis continues to reflect the important role of egg and poultry products contaminated withSalmonella enteritidis.Studies on the burden of salmonellosis in the elderly, the malnourished, and human immunodeficiency virus-infected persons were reported. Pathogenic mechanisms of bacterial invasion of cells, intracellular survival, and production of disease have been elucidated by studying the genetics ofSalmonellaisolates and examining mutant clones inin vitromurine models. Prevention of typhoid fever has focused on defining the immune response to the existing attenuated, live oral vaccine, as well as developing new mutants for immunization against typhoid and other enteric pathogens. Quinolone antibiotics continue to play an important role in the therapy of all forms of salmonellosis including typhoid fever. Quinolones and third-generation cephalosporins may be particularly helpful in treating resistant isolates ofSalmonella typhi.However, caution should be exercised in using quinolones in children, and they are probably not effective in eradicating convalescent carriage ofSalmonellaorganisms.

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Dysentery,Clostridium difficile—associated diseases, and persistent diarrhea constitute important problems for research priorities. Dysentery, defined by the presence of blood in the diarrheal stool, is commonly caused byShigellaorganisms. The high risk of spread, its elevated rates of morbidity and mortality, and the increasing frequency of multiply antimicrobial-resistant strains, especiallyShigella dysenteriaetype 1, make it important to develop new interventions for the treatment and control of shigellosis. While generally nalidixic acid is effective therapy forShigellastrains resistant to other commonly indicated antimicrobial agents, new options like the third-generation cephalosporins (ceftriaxone) and the fluoroquinolones (norfloxacin) for adults seem to be beneficial in infections caused by multiply resistant strains.C. difficileemerges as the most commonly isolated organism in nosocomial gastrointestinal infections.C. difficileis responsible for up to 30% of antibiotic-associated diarrhea and 90% of pseudomembranous colitis cases. It is commonly acquired and transmitted in the hospital and homes for the elderly. Eradication of the carrier state and other strategies to control the spread ofC. difficileare the major goals in reducing the morbidity and mortality associated with this organism.

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Campylobacter jejuni(and alsoCampylobacter coli) are currently thought to be the number one cause of sporadic bacterial gastrointestinal infection in the United States. Complications do occur, although infrequently, and recent studies suggest a strong association of Campylobacter infection with Guillain-Barré syndrome. There are no specific clinical findings that differentiateCampylobacterspecies from other causes of infection, and diagnosis is dependent on laboratory testing. There are still many clinical laboratories that do not routinely look forC. jejuniin routine stool cultures as should be standard practice. New species ofCampylobacterassociated with gastrointestinal infections have been recently identified that may not be recovered by methods used for the more commonC. jejuni.Clinical studies on antimicrobial therapy of Campylobacter infections show variable effects on symptoms but ensure microbiologic cure. New studies suggest that development of quinolone resistance during therapy is common withCampylobacterspecies, which may limit quinolone therapy in the future.

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Various aspects of gastrointestinal infections caused byCandida, Cryptosporidium, andBlastocystisorganisms remain controversial. WhetherCandidaspecies can serve as etiologic agents of enteritis remains debatable despite a recent prospective study of antibiotic-associated diarrhea. Also questionable is whether benign esophageal disease can be caused byCandidaspecies. These studies are reviewed in context with studies concerning the pathogenicity ofCandida albicans.Cryptosporidiosis is an acquired immunodeficiency syndrome-defining illness but it also occurs in a self-limiting form in normal individuals. Epidemiologic evidence suggests that asymptomatic cryptosporidiosis occurs in children and can be a zoonosis. New antiparasitic therapies are under investigation. These therapies are discussed along with recent observations concerning the immunology of this disease. Enteritis due toBlastocystis hominisremains enigmatic. Evidence continues to accumulate suggesting thatBlastocystisspecies can act as etiologic agents. Improved methods for visualizing organisms in stool suggests that the organism is more abundant than previously believed.

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Rotavirus is probably the single most important cause of severe pediatric gastroenteritis, although pathogenicEscherichia colimay be more important in some parts of the developing world. Progress in rotavirus vaccine development has been somewhat disappointing in the past year. Efforts to better understand the role of cell-and antibody-mediated immunity to rotavirus disease may ultimately prove useful in vaccine design. Astrovirus has proven to be an important cause of pediatric gastroenteritis in both the developed and developing world. The production of recombinant Norwalk virus capsids should facilitate the production of greatly improved diagnostic reagents and could serve as a possible vaccine. The role ofHelicobacter pyloriin childhood disease is beginning to be explored. Likewise, vertical transmission of hepatitis C and the prognoses of neonatal and childhood hepatitis C infection are under active investigation.

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

74 years of age). Food (chicken, eggs, fish, and unpasteurized milk) and water are the main vehicles. Risk factors include malnourishment, extremes of age, travel, antimicrobial therapy, and underlying illness (eg, human immunodeficiency virus). Diarrhea has the broadest differential of pathogens of any common infectious syndrome. Nearly one third of cases of diarrhea in the United States are caused by viruses. Bacteria, protozoa, and algae account for the remaining infectious cases. The incubation period, fever, microscopic examination of the stool, and characterization of the host are important in the initial diagnostic evaluation. Antimicrobial therapy may shorten the clinical illness by 1 to 3 days in select settings.

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:0951-7375    

出版商:OVID    

年代:1993

数据来源: OVID