In vitro activity of Bay 12-8039, a new 8-methoxyquinolone, compared to the activities of 11 other oral antimicrobial agents against 390 aerobic and anaerobic bacteria isolated from human and animal bite wound skin and soft tissue infections in humans

The in vitro activity of Bay 12-8039, a new oral 8-methoxyquinolone, was compared to the activities of 11 other oral antimicrobial agents (ciprofloxacin, levofloxacin, ofloxacin, sparfloxacin, azithromycin, clarithromycin, amoxicillin clavulanate, penicillin, cefuroxime, cefpodoxime, and doxycycline) against 250 aerobic and 140 anaerobic bacteria recently isolated from animal and human bite wound infections. Bay 12-8039 was active against all aerobic isolates, both gram-positive and gram-negative isolates, at < or = 1.0 microg/ml (MICs at which 90% of isolates are inhibited [MIC90s < or = 0.25 microg/ml) and was active against most anaerobes at < or = 0.5 microg/ml; the exceptions were Fusobacterium nucleatum and other Fusobacterium species (MIC90s, > or = 4.0 microg/ml) and one strain of Prevotella loeschii (MICs, 2.0 microg/ml). In comparison, the other quinolones tested had similar in vitro activities against the aerobic strains but were less active against the anaerobes, including peptostreptococci, Porphyromonas species, and Prevotella species. The fusobacteria were relatively resistant to all the antimicrobial agents tested except penicillin G (one penicillinase-producing strain of F. nucleatum was found) and amoxicillin clavulanate.     

Venous blood arterialization and parameters from the minimal models of glucose disappearance and post-hepatic insulin delivery

A dot-blot hybridisation assay using high molecular weight DNA as whole chromosomal probes was used to differentiate Bacteroides tectum from Bacteroides fragilis. 32P-labelled probes were compared with digoxigenin (DIG)-labelled probes. The whole chromosomal probes were specific--differentiating B. tectum from B. fragilis and both from a variety of other species (including other members of the genera Bacteroides, Fusobacterium, Eubacterium, and Prevotella) found in normal and abnormal mouths of cats and horses. However, even at very high stringencies, B. tectum homology groups I, II and III were not distinguishable from one another using either 32P-labelled or DIG-labelled probes. Thus, DIG-labelled whole chromosome probes directed against cellular DNA released directly onto nitrocellulose membranes is considered a useful method for diagnostic veterinary laboratories wishing to identify B. tectum and distinguish it from B. fragilis and other oral anaerobic flora of cats.     

Investigations into the occurrence and the antibiotic susceptibility of gram negative anaerobes of the genera Bacteroides, Prevotella, Porphyromonas and Fusobacterium in specimens obtained from diseased animals

From different samples of 247 diseased animals (cattle, sheep, goat, horse, pig, dog, cat, rodent, zoo-animals), 410 strains of gram-negative anaerobes were cultured. 297 isolates (72.4%) could be differentiated to the species level by using cultural-biochemical methods, gaschromatography and cell-wall-lipidanalysis. They belonged to 29 different species. For an additional 113 strains (27.6%) only the genus could be determined. Bacteria belonging to the genus Fusobacterium occurred with the highest isolation rates (36% of all strains) in the samples examined, followed by Bacteroides spp. (26.1%), Prevotella spp. (19.9%) and Prophyromonas spp. (17.8%). Fusobacterium necrophorum was the single species isolated most frequently. Antibiotic susceptibility tests by E-test were performed on 100 strains belonging to the the above mentioned genera. Of these strains 18% were resistant to penicillin and 20% to tetracycline. The resistant strains belonged mainly to the Bacteroides fragilis-group. Resistant rates to most other antimicrobial agents tested were Amoxicillin in combination with clavulanic acid: 1%, Chloramphenicol: 3%, Clindamycin:8%. All 100 selected strains proved to be susceptible to Metronidazol.     

In vitro activity of fleroxacin against multiresistant gram-negative bacilli isolated from patients with nosocomial infections

In order to evaluate the in vitro activity of fleroxacin against nosocomial gram-negative organisms, 263 multiresistant gram-negative bacilli (203 Enterobacteriaceae and 60 non-fermenting gram-negative bacilli) were isolated from adult patients with nosocomial infections. The different patterns of resistance to eight different antimicrobial agents (ampicillin, carbenicillin, piperacillin, cephalothin, cefamandole, ceftazidime, gentamicin and amikacin) were determined by minimum inhibitory concentration (MIC), using the agar dilution method. The most prevalent multiresistant species isolated were Klebsiella pneumoniae (28.9%), Escherichia coli (24%) and Pseudomonas aeruginosa (12.2%). All these bacterial strains showed three to five resistance patterns to at least three different antibiotics. Resistance to ceftazidime was observed in at least one of the resistance patterns of isolated bacteria. The activity of fleroxacin against multiresistant enteric bacteria was excellent; these strains showed a susceptibility of 79-100%. The susceptibility of P. aeruginosa to antipseudomonal agents was low; however, the activity of fleroxacin against these strains was higher than 60% (MIC < or = 2 microg/ ml), broadly comparable with ciprofloxacin. The resistance to fluoroquinolones detected in this study was no cause for alarm (3%). Consequently, fleroxacin maintains a remarkable activity against Enterobacteriaceae and remains highly active against other gram-negative bacilli. Nevertheless, actions directed at preventing or limiting resistance will be crucial to maintain the viability of fluoroquinolones as important therapeutic agents.     

Organisms isolated from dogs and cats with anaerobic infections and susceptibility to selected antimicrobial agents

OBJECTIVE: To determine the prevalence of obligate anaerobic bacteria in bacterial infections in dogs and cats and susceptibility to selected antimicrobial agents. DESIGN: Case series. SAMPLE POPULATION: Specimens from 1,267 dogs and 243 cats. PROCEDURE: Standard anaerobic and aerobic bacterial culture methods were used. Anaerobic isolates were tested for susceptibility to selected antimicrobial agents. RESULTS: Obligate anaerobic bacteria were isolated from 199 (15.7%) and 69 (28.4%) specimens obtained from dogs and cats, respectively. More than half of the specimens that contained obligate anaerobic bacteria were from draining tracts (exclusively dogs), pleural fluid, abscesses, bones, the respiratory tract, or the abdominal cavity. The most commonly isolated obligate anaerobic bacteria (approx 70% of all isolates) were Bacteroides spp, Peptostreptococcus spp, Fusobacterium spp, and Porphyromonas spp. Eighty percent of the specimens that contained obligate anaerobic bacteria also contained facultative anaerobic or aerobic organisms. The organisms most commonly isolated in association with obligate anaerobic bacteria were members of the family Enterobacteriaceae (Escherichia coli was the most common), Pasteurella spp, and Staphylococcus intermedius. Ninety-seven obligate anaerobic isolates were tested for susceptibility to ampicillin, amoxicillin-clavulanic acid, chloramphenicol, clindamycin, and metronidazole. All were susceptible to amoxicillin-clavulanic acid and chloramphenicol, and most were susceptible to metronidazole. Only 71% of the Bacteroides isolates were susceptible to ampicillin, and only 83% were susceptible to clindamycin. Only 80% of the Clostridium isolates were susceptible to clindamycin, but all were susceptible to ampicillin. CLINICAL IMPLICATIONS: Data on sites and conditions from which anaerobic bacteria are commonly isolated, along with results of susceptibility testing, may be useful in designing antimicrobial treatment regimens.     

Susceptibility of anaerobic bacteria to 23 antimicrobial agents

The antimicrobial susceptibility of 492 anaerobic bacteria, the majority of which were recent clinical isolates, was determined by the agar dilution technique. Penicillin G was active against most of the strains tested at 32 U or less/ml, but only 72% of Bacteroides fragilis strains were susceptible at this level and 9% required 256 U or more/ml. Ampicillin was effective against most of the strains except B. fragilis at 16 mug or less/ml. Amoxicillin was active against only 31% of B. fragilis, 76% of other Bacteroides species, and 67% of Fusobacterium species at 8 mug/ml. Two new penicillins, mezlocillin and azlocillin, were similar to ampicillin in their activity. Carbenicillin and ticarcillin inhibited all but a few strains at 128 mug or less/ml. BLP 1654 was somewhat more active than penicillin G against B. fragilis but had similar activity against other anaerobes. Cephalothin was inactive against B. fragilis, and only 65% of other Bacteroides species were inhibited by 32 mug or less/ml. It was effective against all other anaerobes at that level. Cefamandole showed somewhat greater activity than cephalothin against B. fragilis but generally less activity against gram-positive organisms. Cefazaflur (SKF 59962) was comparable to cephalothin against B. fragilis. Cefoxitin was distinctly more active than cephalothin against B. fragilis. These latter two agents were less active than cephalothin against the gram-positive anaerobes. Chloramphenicol remains active against anaerobic bacteria at 16 mug or less/ml, with rare exceptions. Thiamphenicol was similar to chloramphenicol in its activity. Clindamycin was very active against most of the anaerobes at 8 mug or less/ml. Erythromycin and josamycin were also tested, with josamycin showing greater activity against B. fragilis than either erythromycin or clindamycin. A new oligosaccharide, everninomicin B, was less active than clindamycin against B. fragilis but more active against clostridia and some of the other strains tested. Most of the groups of bacteria tested demonstrated a trend toward resistance to tetracycline. Doxycycline and minocycline were somewhat more active than was tetracycline. Metronidazole was active against the majority of the anaerobes tested; resistance ws demonstrated by some of the gram-positive cocci and gram-positive, non-sporeforming bacilli.     

Erythromycin, clarithromycin, and azithromycin: use of frequency distribution curves, scattergrams, and regression analyses to compare in vitro activities and describe cross-resistance

MICs of erythromycin, clarithromycin, and azithromycin for 852 recent clinical isolates were determined by broth microdilution methods. Frequency distribution curves, scattergrams, and regression analyses were used to compare in vitro activities and describe cross-resistance. Clarithromycin was the most active drug against Bacteroides spp. but the least active against Haemophilus influenzae. Azithromycin was most active against H. influenzae, Moraxella catarrhalis, Pasteurella multocida, and Fusobacterium spp. but the least active against Streptococcus spp. and Enterococcus spp. All three drugs had equivalent activities against Staphylococcus spp. and gram-positive anaerobes. None of the three drugs was particularly active against members of the family Enterobacteriaceae or nonfermentative gram-negative bacilli, although concentrations of 4 micrograms of azithromycin per ml inhibited some strains of the family Enterobacteriaceae (particularly Escherichia coli and Citrobacter diversus) and Acinetobacter baumannii. Although relative drug activities varied by organism, organisms relatively susceptible to one were relatively susceptible to all and organisms relatively resistant to one were relatively resistant to all; an exception was fusobacteria, which were usually susceptible only to azithromycin. Cross-susceptibility and cross-resistance were, therefore, the rule (except for Fusobacterium spp.), although the percentage of susceptible organisms could be varied considerably on the basis of the selection of breakpoints.     

Transformation of vibrios with R factors from enterobacteria

The microflora of normal skin in 16 patients with repeated staphylococcal and streptococcal skin infections was examined to determine whether abnormalities existed which would indicate a protective role for the indigenous flora against colonization by pathogens. Five sites-hands, feet, axilla, groin and back-were examined quantitatively and qualitatively and compared with a control group. Total populations of indigenous flora were significantly higher from patients with repeated skin infections of the back, axillae and feet. The frequency of isolation of different species from normal skin was comparable between the control and experimental groups, with the exception of the incidence of Staphylococcus aureus and Proteus species which were isolated only from patients with repeated skin infections. Gram-negative bacteria were isolated with comparable frequency between the two groups, but patients with repeated skin infections tended to carry gram-negative bacteria on multiple sites. It was concluded from the high population of indigenous flora and the types of microogranisms present that the microflora of normal skin did not appear to protect patients with repeated skin infections against colonization by pathogens. The presence of high populations of Staphylococcus aureus on the normal skin of patients with repeated skin infections would appear to be the most important contributing factor.     

In vitro activity of rosamicin and erythromycin against a group of nonfermenting gram-negative bacilli

The in vitro inhibitory activity of rosamicin and erythromycin against 283 strains of nonfermenting, gram-negative bacilli was determined by using a broth dilution procedure. Rosamicin demonstrated greater activity than erythromycin against most strains tested. A number of species demonstrated significantly lower minimum inhibitory concentrations to rosamicin and would fall within the therapeutic range of the drug based on current pharmacological data.     

Investigations of the normal stability of Chopart''s joint (author''s transl)

A total of 132 strains of anaerobic bacteria were tested for susceptibility to josamycin, using a broth dilution technique. All strains of Peptococcus species, Peptostreptococcus species, and Bacteroides fragilis were inhibited by 2 mug or less per ml. Seventy percent of these susceptible strains were also killed by 2 mug or less of josamycin per ml. However, 2 of 12 Clostridium species and 6 of 10 Fusobacterium species had minimum inhibitory concentrations of 32 mug or more per ml.     

Topical antimicrobial prophylaxis of nosocomial pneumonia in mechanically ventilated patients. Microbiological observations

Generally, reduction of colonization and infection with potentially pathogenic microorganisms in intensive care units (ICU) is attempted by a combination of antimicrobial agents administered topically in the digestive tract and systematically. We tested the efficacy of topical antimicrobial prophylaxis of the oropharynx and stomach administered in combination with sucralfate without systemic prophylaxis in 25 mechanically ventilated ICU patients. The regimen successfully reduced colonization with potentially pathogenic microorganisms in the oropharynx and trachea without modifying the intestinal flora. However, colonization and infections with gram-positive cocci and gram-negative rods other than Enterobacteriaceae and Pseudomonadaceae and resistant to one or both the antimicrobial agents used were observed.     

Increasing ciprofloxacin resistance among prevalent urinary tract bacterial isolates in Bangladesh

Ciprofloxacin was evaluated along with other commonly used antibiotics against a total of 425 clinical isolates obtained from urine samples. Samples were collected from outdoor patients from different parts of Dhaka city. Susceptibility tests were done by the standardized disk diffusion method. Among the tested drugs, the percent susceptible rates observed were: ciprofloxacin (74%), ampicillin (29%), cephalexin (54%) and trimethoprim-sulfamethoxazole (43%) tested against all organisms; gentamicin (73%) tested against gram-negative organisms and erythromycin (72%) tested against gram-positive organisms. Ciprofloxacin showed better activity against gram-negative isolates (80%) compared to the other antibiotics. However, strains highly resistant to ciprofloxacin were detected among commonly isolated gram-negative urinary pathogens: Escherichia coli (18%), Klebsiella species (19%) and Pseudomonas species (30%). Overall susceptibility rate for gram-positive cocci was significantly low for all the antibiotics tested including ciprofloxacin (62%). Minimal inhibitory concentration (MIC) of ciprofloxacin was measured for all resistant and susceptible urinary tract infection (UTI) isolates. This study indicates emerging ciprofloxacin resistance among most UTI bacterial pathogens. Increasing resistance against ciprofloxacin demands coordinated monitoring of its activity, and rationale use of the antibiotic in UTI.     

Urinary tract infections in the first three months following kidney transplantation

Eighty kidney transplants were examined. During the first three months following transplantation, urinary tract infections occurred in 68 patients (85%). Fifty patients (74%) have had a few episodes of infections in the form of either suprainfection or recurrence whereas in the remaining patients there was only one episode of urinary infection. No difference in infection incidence was noted in both men and women. Ninety percent of urinary infections occurred within the first 4 weeks following transplantation. The most frequent cause of the urinary tract infections were gram-negative bacilli of Enterobacteriaceae family. In case of multiple infections there was a high percentage of gram-positive cocci.     

In vitro and in vivo antibacterial activities of T-3761, a new quinolone derivative

T-3761, a new quinolone derivative, showed broad and potent antibacterial activity. Its MICs for 90% of the strains tested were 0.20 to 100 micrograms/ml against gram-positive bacteria, including members of the genera Staphylococcus, Streptococcus, and Enterococcus; 0.025 to 3.13 micrograms/ml against gram-negative bacteria, including members of the family Enterobacteriaceae and the genus Haemophilus; 0.05 to 50 micrograms/ml against glucose nonfermenters, including members of the genera Pseudomonas, Xanthomonas, Acinetobacter, Alcaligenes, and Moraxella; 0.025 micrograms/ml against Legionella spp.; and 6.25 to 25 micrograms/ml against anaerobes, including Bacteroides fragilis, Clostridium difficile, and Peptostreptococcus spp. The in vitro activity of T-3761 against these clinical isolates was comparable to or 2- to 32-fold greater than those of ofloxacin and norfloxacin and 2- to 16-fold less and 1- to 8-fold greater than those of ciprofloxacin and tosulfoxacin, respectively. When administered orally, T-3761 showed good efficacy in mice against systemic, pulmonary, and urinary tract infections with gram-positive and gram-negative bacteria, including quinolone-resistant Serratia marcescens and Pseudomonas aeruginosa. The in vivo activity of T-3761 was comparable to or greater than those of ofloxacin, ciprofloxacin, norfloxacin, and tosufloxacin against most infection models in mice. The activities of T-3761 were lower than those of tosufloxacin against gram-positive bacterial systemic and pulmonary infections in mice but not against infections with methicillin-resistant Staphylococcus aureus. The activities of T-3761 against systemic quinolone-resistant Serratia marcescens and Pseudomonas aeruginosa infections in mice were 2- to 14-fold greater than those of the reference agents.     

Amikacin therapy of severe infections produced by gram-negative bacilli resistant to gentamicin

Amikacin is a new aminoglycoside antibiotic related chemically to kanamycin. It has broad spectrum activity against most gram-negative bacilli. The most important advantage of this aminoglycoside is its activity against gram-negative bacilli which are resistant to gentamicin. Amikacin was given to 22 cancer patients with 24 serious infections produced by gram-negative bacilli resistant to gentamicin and 13 (54 per cent) were cured. Response to amikacin was related to the patients's neutrophil count at the time of infection; neutropenic patients having a lower response rate (30 per cent vs 71 per cent). Side effects included nephrotoxicity (12 per cent) and audiotoxicity (5 per cent). Amikacin is an effective new antibiotic for patients with severe infections produced by gram-negative bacilli resistant to gentamicin.     

Antimicrobial susceptibility patterns of Aeromonas jandaei, A. schubertii, A. trota, and A. veronii biotype veronii

Fifty-six isolates of four Aeromonas species, which have been documented as causative agents of human infections or isolated from human clinical specimens, were subjected to antimicrobial susceptibility testing using a MicroScan WalkAway conventional (overnight incubation) gram-negative panel. The four species tested and the number of isolates of each were as follows: Aeromonas jandaei, 17; A. schubertii, 12; A. trota, 15; and A. veronii biotype veronii, 12. All isolates of A. trota were susceptible to all antimicrobial agents tested, except cefazolin (20% of isolates were resistant) and cefoxitin (13% of isolates were resistant). All isolates of A. schubertii and A. veronii biotype veronii, as well as 88% of A. jandaei isolates, were resistant to ampicillin. Resistance to ampicillin-sulbactam ranged from 25% of A. schubertii strains to 100% of A. veronii biotype veronii strains. Cefazolin resistance ranged from 17% of A. veronii biotype veronii isolates to 59% of A. jandaei isolates. Imipenem resistance was detected in 65% of A. jandaei strains and 67% of A. veronii biotype veronii strains. A. jandaei displayed resistance to piperacillin and ticarcillin in 53 and 71% of the isolates, respectively. A. veronii biotype veronii strains were 100% susceptible to piperacillin and 100% resistant to ticarcillin. These antibiogram data may be useful in establishing the identification of these four species when members of the genus Aeromonas are isolated from human clinical sources.     

Gram-positive anaerobic cocci

Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of organisms defined by their morphological appearance and their inability to grow in the presence of oxygen; most clinical isolates are identified to species in the genus Peptostreptococcus. GPAC are part of the normal flora of all mucocutaneous surfaces and are often isolated from infections such as deep organ abscesses, obstetric and gynecological sepsis, and intraoral infections. They have been little studied for several reasons, which include an inadequate classification, difficulties with laboratory identification, and the mixed nature of the infections from which they are usually isolated. Nucleic acid studies indicate that the classification is in need of radical revision at the genus level. Several species of Peptostreptococcus have recently been described, but others still await formal recognition. Identification has been based on carbohydrate fermentation tests, but most GPAC are asaccharolytic and use the products of protein degradation for their metabolism; the introduction of commercially available preformed enzyme kits affords a physiologically more appropriate method of identification, which is simple and relatively rapid and can be used in routine diagnostic laboratories. Recent reports have documented the isolation in pure culture of several species, notably Peptostreptococcus magnus, from serious infections. Studies of P. magnus have elucidated several virulence factors which correlate with the site of infection, and reveal some similarities to Staphylococcus aureus. P. micros is a strongly proteolytic species; it is increasingly recognized as an important pathogen in intraoral infections, particularly periodontitis, and mixed anaerobic deep-organ abscesses. Comparison of antibiotic susceptibility patterns reveals major differences between species. Penicillins are the antibiotics of choice, although some strains of P. anaerobius show broad-spectrum beta-lactam resistance.     

A study of the structure and functions of the submandibular ganglion

This study examines the prevalence of coagulase-negative Staphylococcus species in normal and mildly inflamed conjunctiva, their sensitivity to antibiotics, and their relationship to the remaining flora. PATIENTS AND METHODS: In 99 patients including 9 HIV-positives in an early stage of the infection, 100 conjunctival swabs were taken and microbiologically investigated for bacteria and fungi. Thirty-four were from healthy eyes. 40 were from patients with chronic (n = 28) and unspecific (n = 12) conjunctivitis, 17 were from patients with a variety of outer inflammatory ocular conditions, and 9 were from the HIV group from uninfected (n = 6) and infected (n = 3) conjunctivae. Samples from each patient were collected with three moistened cotton swabs and directly inoculated onto five different agars, followed by immersion into three specific culture broths. Staphylococci were identified species-wise, the other microorganisms genus-wise. Sensitivity to a broad spectrum of antibiotics was determined by agar diffusion tests. OUTCOME: Staphylococci were found in 89%, which was the highest prevalence genus-wise. Of those, coagulase-negative species accounted for 86%, while coagulase-positive Staphylococcus aureus was isolated in 12% of all swabs. In the 86 smears positive for coagulase-negative staphylococci, 151 different strains were isolated. In these strains, resistance to the 13 tested antibiotics varied from 0% for vancomycin to 66% for penicillin. Strains which were isolated from patients with chronic conjunctivitis showed a greater range of resistance than those from normal flora, with significant levels for ciprofloxacin, gentamycin and kanamycin (Mann-Whitney) U-test: P < 0.05). All except six strains of staphylococci were identified strains represented ten species, of which Staphylococcus epidermidis was most prevalent (74%), but only made up 70% of all isolated strains of the coagulase-negative staphylococci. Staphylococcus aureus and gram-negative bacteria were found significantly more commonly in patients which chronic conjunctivitis than in healthy eyes, while coagulase-negative species of the Micrococcaceae family were significantly more prevalent in the healthy than in the chronically inflamed conjunctiva (chi-square: P < 0.05). CONCLUSION: The conjunctiva can simultaneously host several stems of coagulase-negative staphylococci, which differ in regard to species and resistance to antibiotics. This variety might indicate a microbiological balance of the conjunctiva and be reduced in chronic inflammatory conditions. In patients with chronic conjunctivitis the risk for multiresistant coagulase-negative staphylococci is increased.     

Dental plaque flora of the dog with reference to fastidious and anaerobic bacteria associated with bites

Animal bite wounds are amongst the most common types of traumatic injuries in humans. The organisms isolated from these wounds generally reflect the oral flora of the biting animal, and may be fastidious in nature and difficult to identify. This study was undertaken to determine the prevalence of Eikenella corrodens, Actinobacillus actinomycetemcomitans, Porphyromonas and Prevotella spp. in supragingival dental plaque collected from the right maxillary canine and carnassial teeth and the right mandibular canine tooth of dogs. In part one of the study, 30 dogs were used. E. corrodens was found in 62% of these dogs and 44% of individual plaque samples. A. actinomycetemcomitans was not detected in any of the dogs sampled. In part two, 34 dogs were used to determine the prevalence of the black pigmented anaerobic bacilli (Porphyromonas and Prevotella spp.). Porphyromonas gingivalis was present in 68% of these dogs and 47% of individual plaque samples. Prevotella intermedia was present in 44% of the dogs and 23% of individual plaque samples. The recently described Porphyromonas canoris, Porphyromonas salivosa, Porphyromonas cangingivalis, Porphyromonas cansulci, Porphyromonas crevioricanis and Prevotella denticola species were isolated from only 9%, 6%, 3%, 3%, 3% and 3% of dogs respectively. Porphyromonas gingivicanis was not isolated from any of the animals sampled. In conclusion, black-pigmented anaerobic bacilli were isolated from 91% of the animals sampled and therefore constitute a significant risk with respect to bite wound infections. It is also suggested that the prevalence of E. corrodens in wound infections has been underestimated in previous reports because of use of inappropriate techniques for detecting this organism.     

Antimicrobial activity of the new carbapenem biapenem compared to imipenem, meropenem and other broad-spectrum beta-lactam drugs

The in vitro activity of biapenem was compared to that of imipenem, meropenem and other broad-spectrum beta-lactams. A total of 716 isolates from recent cases of clinical septicemia and an additional 137 stock strains possessing known beta-lactamases or other well-characterized resistance mechanisms were tested. The minimal concentrations inhibiting 90% of strains (MIC90) of Enterobacteriaceae species were for biapenem 0.03 to 1 mg/l and for imipenem 0.25 to 2 mg/l. No member of the Enterobacteriaceae was found to be resistant to biapenem. Biapenem and meropenem were the most active drugs against Pseudomonas aeruginosa, with an MIC90 of 1 mg/l. Biapenem was more active than ceftazidime against most gram-negative and gram-positive bacteria tested. Biapenem was as potent as imipenem against anaerobic bacteria (including Bacteroides fragilis), with an MIC90 of 0.25 mg/l. High MICs of biapenem were demonstrated for Xanthomonas maltophilia, oxacillin-resistant Staphylococcus spp. and Enterococcus spp. These species have demonstrated resistance to other carbapenems and to most of the newer cephalosporins. The results of this study, coupled with previously documented favorable qualities of biapenem, endorse further investigation of this broad-spectrum antibacterial agent for clinical use.