Biomedical subjects

D M Citron

Publications and source records attributed to D M Citron.

107 records · Page 6Linked to original sources

PubMed1982

Impact of cefoperazone therapy on fecal flora.

To evaluate the effects of parenteral cefoperazone therapy upon human fecal flora, fecal specimens obtained from four patients before and during therapy (as well as after therapy for one patient) were cultured quantitatively for facultative, aerobic, and anaerobic bacteria and for fungi. Cefoperazone therapy was associated with major changes in fecal flora. There was suppression to undetectable levels or an appreciable reduction in all anaerobic bacteria as well as suppression of all initially detected Enterobacteriaceae. During therapy, there was acquisition or an increase in counts of Candida spp., so that these became the most numerous fecal microorganisms in all patients. In addition, Pseudomonas spp. and coagulase-negative Staphylococcus sp. were acquired by three patients. These marked alterations in flora have potentially important consequences.

Adult↗

PubMed1981

Toxin-producing bacteria in infants. Lack of an association with sudden infant death syndrome.

After finding enterotoxigenic (ET) Escherichia coli in two consecutive cases of sudden infant death syndrome (SIDS), we initiated a prospective search for ET E coli in SIDS in Manitoba; in addition, we looked for toxigenic Clostridium botulinum and C difficile. In a 21-month period, small- and large-bowel contents were obtained in 33 cases of SIDS, from 32 control subjects, and in ten suspected cases of SIDS. Neither C botulinum nor ET E coli was isolated from any of these; C difficile was cultured from postmortem bowel contents of two SIDS and seven control cases. The overall isolation rate of C difficile was 17%. Despite the fact that two of these cases had toxin detectable in the bowel contents, no evidence of colitis was found in any of the cases with C difficile. We conclude that C botulinum or ET E coli have only a small role, if any, in the etiology of SIDS, and that C difficile is found relatively commonly in the gastrointestinal tract of infants without apparent local or systemic effects.

Aeromonas↗

PubMed1981

New medium selective for Fusobacterium species and differential for Fusobacterium necrophorum.

Fusobacterium egg yolk agar is a new medium selective for Fusobacterium species and differential for Fusobacterium necrophorum. The medium is a Brucella Agar base (Difco Laboratories, Detroit, Mich.) containing vancomycin, neomycin, josamycin, and egg yolk. All species of fusobacteria grew with only minimal inhibition. The mean log difference in counts between Fusobacterium egg yolk agar and control media for 30 strains of seven species of fusobacteria was 0.1922. F. necrophorum typically showed a strong lipase reaction. Most other organisms were significantly inhibited by the medium.

Agar↗

PubMed1980

Serious infection with Leptotrichia buccalis. Report of a case and review of the literature.

Leptotrichia buccalis is an obligately anaerobic, gram-negative rod classified as a member of the family Bacteroidaceae. Organisms found in this family (Bacteroides and Fusobacteria) are frequent causes of severe infection in human beings. L. buccalis is a constituent of normal oral flora. Leptotrichia has rarely been recovered from mixed infections primarily of the head and neck. It has not previously been reported as a cause of serious infection in man. We report a case of cavitary pneumonia and septicemia caused by L. buccalis. The colonial morphology and gram stain of L. buccalis are characteristic. Definitive identification is made by gas-liquid chromatography. Leptotrichia have been shown to contain potent endotoxin. L. buccalis has the potential to be a virulent, pathogenic microorganism, especially in the compromised host.

Bacterial Infections↗

PubMed1980

Dog bite wounds and infection: a prospective clinical study.

We prospectively studied 26 patients with 27 dog bite wounds who sought medical attention in the emergency department. Two distinct populations were found (Fishers Exact Test, P less than or equal to 0.001): 1) those who presented 8 hr to 12 hr post-injury were concerned about rabies or tetanus or surgical wound repair; and 2) those who presented more than 12 hr post-injury were concerned with infection. There was no difference (P > 0.05) in the bacteriology of the two groups. Of all wounds, 74% had aerobic pathogens isolated, including Streptococcus viridans (12 strains), Staphylococcus aureus (five strains), and Pasteurella multocida (eight strains); 41% had anaerobic pathogens isolated, including Bacteriodes species (five strains) and Fusobacterium species (five strains). Gram stains made from wound swabs were specific but insensitive predictor for bacterial growth. Empiric outpatient therapy with oral penicillin (17 patients) and/or dicloxacillin (four patients) was effective.

Animals↗

PubMed1980

The non-value of preoperative and intraoperative cultures in predicting the bacteriology of subsequent wound infection in patients undergoing major head and neck cancer surgery.

A prospective study of patients undergoing major head and neck cancer surgery was undertaken to define the value of preoperative and intraoperative cultures in identifying the patient at "high risk" of wound infection and in predicting the bacteriology of wound infection. One or two days before surgery, the skin of the operative site on the neck, the oropharynx and anterior nares were swabbed. an intraoperative wound culture was obtained after the pharyngeal defect was closed and the wound irrigated with water. All cultures were processed for aerobes in the Anaerobic Bacteriology Research Laboratory at Wadsworth Hospital Center. Wound infections developed in 10 of 31 patients who received cefazolin prophylactically and 21 of 25 patients who received no perioperative antibiotics. Fifty-five percent of infected patients and 68% of noninfected patients demonstrated potential pathogens preoperatively. A potential pathogen isolated preoperatively or intraoperatively was subsequently recovered from 35% of infected wounds. The majority of infected wound cultures grew one or more additional pathogens. A poor correlation was also noted between preoperative nasal Staphylococcus aureus isolation and subsequent recovery from wound infections. We conclude that preoperative and intraoperative aerobic wound cultures are not predictive of the "high risk" patient or of the bacteriology of subsequent wound infection in major head and neck cancer surgery.

Bacteriological Techniques↗

PubMed1979

Bacteriology of rattlesnake venom and implications for therapy.

Although the incidence of infection secondary to the bites of venomous snakes remains unknown, the routine use of prophylactic antimicrobial therapy is advocated. In this study, the venom from 15 rattlesnakes was cultured, and 58 aerobic and 28 anaerobic strains of bacteria were isolated. The most common species isolated were Pseudomonas aeruginosa, Proteus species, coagulase-negative staphylocci, and Clostridium species. Bacteroides fragilis was also recovered. When the fang sheaths of four additional rattlesnakes were retracted and the fangs of these snakes decontaminated, 50% of the samples of venom had no bacterial growth (P = 0.035). Until a clinical study is performed, the use of antimicrobial therapy that reflects that complex oral flora of rattlesnakes is still recommended in most cases of envenomization.

Alcaligenes↗

PubMed1978

Infections following clenched-fist injury: a new perspective.

Fifteen cases of clenched-fist injury were studied by aerobic, anaerobic, and 10% CO2 cultures. Anaerobic bacteria and Eikenella corrodens were prominent pathogens, being recovered in 60% and 20% of cases, respectively. These organisms are more susceptible to penicillin than to penicillinase-resistant penicillins or cephalosporins. All clenched-fist injuries should be cultured in aerobic, anaerobic, and 10% CO2 atmospheres. We recommend the use of both penicillin and a penicillinase-resistant penicillin as initial empiric therapy.

Bacteriological Techniques↗

PubMed1978

Bacteriology of human and animal bite wounds.

Seventy-three patients with bite wounds (16 patients with clenched-fist injuries, 18 with human bite wounds, and 39 with animal bites) were cultured aerobically and anaerobically. A total of 33 of 34 patients with human bites and clenched-fist injuries and 33 of 39 patients with animal bites had aerobic or facultative bacteria isolated from their wounds. A total of 224 strains of aerobic or facultative bacteria were isolated, the most frequent isolate being alpha-hemolytic streptococci (50 strains). Staphylococcus aureus was isolated from 18 wounds. Penicillin-resistant gram-negative rods were infrequently isolated (12 strains). Anaerobic bacteria were isolated in 18 of 34 human bite wounds and clenched-fist injuries and 16 of 39 animal bite wounds. A total of 88 anaerobic strains was isolated, the most common being various Bacteroides species (36 strains).

Aerobiosis↗

PubMed1978

Animal bites.

Explore the source record for details and available documents.

Animals↗

PubMedDate not supplied

Cefoxitin for treatment of infections due to anaerobic bacteria.

Twenty-seven patients with 29 infections due to anaerobic or mixed anaerobic-aerobic bacteria were treated with cefoxitin. From the 27 patients 99 isolates of anaerobic bacteria and 70 isolates of aerobic bacteria were recovered. Twelve pleuropulmonary infections, 12 soft tissue infections, three bone infections, and two intraabdominal infections were treated. Twenty-six of the 29 infections were completely or partially eradicated; the remaining three infections were unchanged. One-third of the patients experienced phlebitis; in two instances severe phlebitis caused discontinuation of therapy. In this study cefoxitin appeared to be an effective single agent for the therapy of infections due to specific anaerobic bacteria or to a mixed flora of anaerobic and aerobic bacteria.

Adult↗

PubMedDate not supplied

Gram-negative anaerobic bacilli: their role in infection and patterns of susceptibility to antimicrobial agents. I. Little-known Bacteroides species.

The role in infection and the patterns of susceptibility to antimicrobial agents of 17 infrequently reported species of Bacteroides were studied. The findings of this research are summarized, and the literature dealing with recovery of these species from both the normal flora and infections of humans is reviewed. During a six-year period, 22% of 679 specimens from infections due to anaerobic bacteria that were studied by the authors yielded one or more of these "other Bacteroides species" (OBS). The most commonly isolated OBS were Bacteroides ruminicola subspecies brevis (63 patients), Bacteroides ureolyticus (38), Bacteroides bivius (26), and Bacteroides disiens (17). Appreciable resistance of some isolates to the beta-lactam antibiotics, erythromycin, and the tetracyclines was noted, whereas all strains were inhibited by chloramphenicol and metronidazole and almost all were inhibited by clindamycin. The data indicate that OBS are present in infection much more often than has been reported previously. The resistance of certain strains to some commonly used antimicrobial agents may necessitate a reassessment of the initial, empiric therapy of infections due to anaerobic bacteria.

Abdomen↗

PubMedDate not supplied

Gram-negative anaerobic bacilli: Their role in infection and patterns of susceptibility to antimicrobial agents. II. Little-known Fusobacterium species and miscellaneous genera.

Twenty infrequently reported species of gram-negative anaerobic bacilli other than Fusobacterium nucleatum, Fusobacterium necrophorum, and members of the genus Bacteroides were studied with regard to their role in infection and their susceptibility to antimicrobial agents. In addition, the literature regarding the recovery of these organisms from both the normal flora and infections of humans was reviewed. During a six-year period at the Wadsworth Clinical Anaerobic Bacteriology Research Laboratory (Veterans Administration Wadsworth Medical Center, Los Angeles, Calif.), 39 (6%) of 679 specimens obtained from anaerobic infections yielded "other gram-negative anaerobic bacilli" (OGNAB). Fusobacterium naviforme, Fusobacterium gonidiaformans, Fusobacterium varium, Fusobacterium mortiferum, and Fusobacterium russii were the most commonly isolated OGNAB. Most of the OGNAB tested were resistant to erythromycin, and most strains, except for F. varium, were susceptible to beta-lactam antibiotics and clindamycin. Chloramphenicol and metronidazole were active against all strains of OGNAB tested. Certain Fusobacterium species are undoubtedly previously unrecognized members of the normal flora of the oropharynx, upper respiratory tract, or urogenital tract and may be present in infections derived from these floras.

Adult↗

PubMedDate not supplied

Brain abscess and cerebritis.

Eighteen consecutive cases of brain abscess or cerebritis seen at the Veterans Administration Wadsworth Medical Center (Los Angeles, Calif.) during 1970-1982 were analyzed. Fifteen occurred after the computerized axial tomographic (CT) scanner for diagnosis and follow-up became available in 1976. The patient population included 14 individuals with significant underlying medical problems and with a clearly identifiable contiguous or distant source. Four patients had multiple brain abscesses; the most common site of involvement in the remaining 14 patients was the parietal lobe. Microorganisms were isolated from 14 patients and included a variety of aerobic and anaerobic bacteria. Of the 27 isolates, 12 were microaerophilic species or strictly anaerobic bacteria. Therapy was most often a combination of surgical drainage and antimicrobial agents. Usually the drug regimen included penicillin and chloramphenicol and, more recently, the combination of penicillin and metronidazole. One of the two patients with brain abscess treated with antimicrobial agents alone died. Two patients with presumed bacterial cerebritis improved with chemotherapy alone. This study reaffirms the important role of anaerobes in brain abscess. The advent of the CT scanner appears to have been a valuable development in both diagnosis and monitoring of therapy, but mortality (22%) still remains relatively high. Although metronidazole will likely prove to represent a significant advance in antimicrobial therapy, surgical drainage still appears to be the mainstay of therapy for treatment of established abscesses.

Adolescent↗

PubMedDate not supplied

Role of anaerobic bacteria in bite-wound infections.

The etiologic agents usually involved in wound infections due to human or animal bites are the aerobic skin flora of the victim, e.g., Staphylococcus aureus, and/or the aerobic oral flora of the biter, e.g., Pasteurella multocida. While anaerobic bacteria are predominant in the normal oral flora of humans and animals, their importance in the pathogenesis of bite-wound infections has not been stressed. Most investigators in this field have either not cultured these wounds for anaerobic bacteria or not utilized optimal culture techniques. In a series of studies on human and animal bite wounds, methods that are optimal for recovery of anaerobic bacteria were used. Anaerobes were found in significant quantities in 39% of animal bite wounds, 50% of human bite wounds, and 56% of clenched-fist injuries. Several species of anaerobes usually were present in the wounds and always were present in mixed culture with aerobic oral flora. The anaerobes most commonly isolated included Bacteroides asaccharolyticus, Bacteroides bivius, Bacteroides disiens, Bacteroides melaninogenicus, Bacteroides oralis, Bacteroides ruminicola, Bacteroides pneumosintes, Bacteroides ureolyticus, Fusobacterium nucleatum, Fusobacterium russii, Peptococcus species, Peptostreptococcus species, and Veillonella species. Initial, empiric antimicrobial therapy for bite wounds should be directed against potential anaerobic as well as aerobic pathogens.

Animals↗

PubMedDate not supplied

Specimen collection and transport, anaerobic culture techniques, and identification of anaerobes.

Excellent progress has been made in recent years in the development and refinement of technical materials used for transporting specimens and growing and identifying anaerobes. Several good systems for maintaining swabs and vials for transporting liquid specimens are commercially available. Anaerobic bags are useful for transporting unusual specimens, such as tissue or bone, and are also a convenient way to incubate small numbers of plates. Several different types of anaerobic chambers, with or without gloves, and separately enclosed incubators are being used by an increasing number of laboratories. Prereduced anaerobically sterilized plates and biochemicals in tubes are available from several commercial sources. A new rapid identification microsystem based on tests for performed enzymes permits identification of many clinically significant anaerobes to the species level in 4 hr.

Actinomyces↗

PubMedDate not supplied

Susceptibility testing of anaerobes--fact, fancy, and wishful thinking.

Some of the problems encountered in anaerobic bacteriology and anaerobic susceptibility testing are reviewed. These include the lack of identification of Bacteroides fragilis group species, standardization of test media, methodology, and clinically relevant minimum inhibitory concentration breakpoints. Methodologic variations may lead to marked differences in the degree of activity reported, especially for newer antimicrobial agents. Studies on the correlation of clinical efficacy and in vitro susceptibility data performed by the various techniques are needed.

Anti-Bacterial Agents↗