Sydney M. Finegold

"The bacteria typically described from biliary tract infection include Escherichia coli, Klebsiella, Enterobacter, and enterococci. It has also been recognized for some time that Clostridium perfringens may occasionally be involved in serious complications of biliary tract infection such as sepsis and emphysematous cholecystitis. Other anaerobes, including various Bacteroides and Fusobacterium sp, clostridia other than C perfringens, anaerobic cocci and streptococci, and Actinomyces have been reported from a variety of biliary tract infections, usually as single case reports ... More recently, several reports indicate that anaerobes, and especially B fragilis, may be more common in biliary tract infections than had been appreciated ... Anaerobes have been recovered in approximately 40% of such infections; B fragilis is the most common anaerobe encountered. Anaerobes may also be found, as aerobes are, in asymptomatic bactibilia."

"Anaerobic bacteria produce many different enzymes that are of importance in providing nutrients to the bacterial cell, as virulence factors, and in permitting organisms to colonize or survive under adverse conditions (including exposure to antimicrobial agents). Some enzymes effect several types of modifications to bile acids, neutral steroids, and corticosteroids. Anaerobes are clearly important in a variety of infections in humans and animals as well as in various other types of pathologic processes."

"There is an impressive incidence of anaerobes in major infections involving the lung and pleural space, intra-abdominal sites, and the female genital tract. Almost all anaerobic infections are endogenous in origin. Therapy consists of making the environment such that anaerobes find it difficult to proliferate, checking the spread of anaerobes into healthy tissues, and neutralizing the toxins of anaerobes."

"The field of infectious diseases covers many entities that can be considered true medical emergencies. Included are meningitis, brain abscess, spinal epidural abscess, epiglottitis, pneumonia, bacteremia, endocarditis, certain intraabdominal infections, gas gangrene, and necrotizing fasciitis. Because emergencies related to infectious agents are potentially the most readily reversible of all medical emergencies, it behooves us to diagnose them as rapidly and specifically as possible so that appropriate life-saving therapy may be begun expeditiously."

"Anaerobes are prevalent on all mucosal surfaces and virtually all anaerobic infections are endogenous. Two thirds of anaerobic infections involve five anaerobic organisms or groups—the Bacteroides fragilis group, the Bacteroides melaninogenicus-Bacteroides asaccharolyticus group, Fusobacterium nucleatum, the anaerobic cocci, and Clostridium perfringens. Conditions that lower the oxidation-reduction potential and disrupt the mucosal surface (eg, vascular problems, malignant neoplasms, and surgery) lead to infection with anaerobes. Clues to anaerobic infection include foul odor, gas, tissue destruction, underlying malignant neoplasms, and the unique appearance of certain anaerobes on Grams stain. Specimens must be collected to avoid normal flora and transported to the laboratory under anaerobic conditions. Therapy involves surgical débridement and drainage and the use of various antimicrobial agents. Antimicrobial agents must be used for extended periods to avoid relapse."

"Several classes of antimicrobial agents (e.g., penicillins, cephalosporins, tetracyclines, chloramphenicol, and clindamycin) are useful in treatment of infections due to anaerobic bacteria. However, certain anaerobic bacteria have shown a striking resistance to antimicrobial agents. In vitro susceptibility tests are useful for selection of optimal therapy. The choice of agent depends, to some extent, on the organisms responsible for the infection. Bacteroides fragilis is the most commonly encountered anaerobe, and it is also the most resistant to antimicrobial agents. Other factors influencing the selection of therapy include pharmacologic characteristics, degree of bactericidal activity, and toxicity. Proper therapy for anaerobic infections often requires intensive antimicrobial therapy for a prolonged period. Surgical intervention, including drainage of abscesses and excision of necrotic tissue, is important."