Aerobic and anaerobic bacteriology of cutaneous abscesses in children

Specimens from 209 cutaneous abscesses in children were cultured for aerobic and anaerobic microorganisms. Of these, nine (4%) were sterile and 51 (24%) yielded pure cultures that were predominantly Staphylococcus aureus. The rest of the abscesses yielded growth of two or more aerobic and/or anaerobic organisms. The data were organized according to these anatomic locations: head, neck, trunk, finger, nailbed, hand, leg, buttocks, perirectal, and vulvovaginal areas. Aerobic bacteria only were present in 92 specimens (46%), anaerobes only were isolated in 52 (26%), and mixed aerobic and anaerobic bacteria were present in 56 abscesses (28%). A total of 467 isolates (270 anaerobes and 197 aerobes) were recovered, accounting for 2.3 isolates per specimen (1.3 anaerobes and 1.0 aerobes). The presence of more than one anaerobe per abscess was obtained from the vulvo-vaginal, buttocks, perirectal, finger, nailbed, and head areas. Aerobes were more prevalent in the neck, hand, leg, and trunk areas. The predominant aerobes recovered were: S aureus (89 isolates), alpha- and nonhemolytic streptococci (29), group A beta-hemolytic streptococci (16), Enterobacter (10), and Escherichia coli (8). The predominant anaerobes recovered were anaerobic Gram-positive cocci (79 isolates), Bacteroides sp (116, including 31 B melaninogenicus group and 29 B fragilis group), and Fusobacterium sp (39). Our findings indicate the polymicrobial nature and predominance of anaerobes in cutaneous abscesses in children in perirectal, head, finger, and nailbed areas.     

Synthesis of novel cyclic protease inhibitors using Grubbs olefin metathesis

The microbiologic features of infected sinus aspirates in nine children with neurologic impairment were studied. Anaerobic bacteria, always mixed with aerobic and facultative bacteria, were isolated in 6 (67%) aspirates and aerobic bacteria only in 3 (33%). There were 24 bacterial isolates, 12 aerobic or facultative and 12 anaerobic. The predominant aerobic isolates were Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus (2 each) and Proteus mirabilis, Pseudomonas aeruginosa, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae (1 each). The predominant anaerobes were Prevotella sp. (5), Peptostreptococcus sp. (4), Fusobacterium nucleatum (2), and Bacteroides fragilis (1). Beta-lactamase-producing bacteria were isolated from 8 (89%) patients. Organisms similar to those recovered from the sinuses were also isolated from tracheostomy site and gastrostomy wound aspirates in five of seven instances. This study demonstrates the uniqueness of the microbiologic features of sinusitis in neurologically impaired children, in which, in addition to the organisms known to cause infection in children without neurologic impairment, facultative and anaerobic gram-negative organisms that can colonize other body sites are predominant.     

Efficacy of itraconazole in children with Trichophyton tonsurans tinea capitis

The microbiology of needle aspirates from 40 inflamed cervical lymph glands was studied for aerobic and anaerobic bacteria, fungi and mycobacteria. Forty-two bacterial, 11 mycobacterial and six fungal isolates were isolated. Aerobic bacteria only were recovered in 11 (27.5%), anaerobes alone in five (12.5%) and mixed aerobic and anaerobic bacteria in seven (17.5%). Mycobacterium sp. were recovered in 11 (27.5%) and fungi in six (15%). The recovery of anaerobes was associated with dental infection. Eighteen aerobic bacteria were isolated and the predominant ones were Staphylococcus aureus (eight isolates) and group A streptococci (four). Twenty-four anaerobic bacteria were recovered and the predominant ones were: Prevotella sp. (six), Peptostreptococcus sp. (five), Propionibacterium acnes (four) and Fusobacterium sp. (three). These findings demonstrate the role of anaerobic organisms in cervical lymphadenitis and the need to culture aspirated material from the glands for both aerobic and anaerobic microorganisms.     

Aerobic and anaerobic microbiology of surgical-site infection following spinal fusion

The aerobic and anaerobic microbiology of surgical-site infections (SSI) following spinal fusion was retrospectively studied. This was done by reviewing the clinical and microbiological records at the Naval Hospital in Bethesda, Md., from 1980 to 1992. Aspirates of pus from 25 infection sites showed bacterial growth. Aerobic bacteria only were recovered from 9 (36%) specimens, anaerobic bacteria only were recovered from 4 (16%), and mixed aerobic and anaerobic bacteria were recovered from 12 (48%). Sixty isolates were recovered: 38 aerobes (1.5 isolates per specimen) and 22 anaerobes (0.9 isolate per specimen). The predominant aerobes were Escherichia coli (n = 8) and Proteus sp. (n = 7). The predominant anaerobes were Bacteroides fragilis group (n = 9) and Peptostreptococcus sp. (n = 6) isolates. An increase in recovery of E. coli and B. fragilis was noted in patients with bowel or bladder incontinence. This study highlights the polymicrobial nature of SSI and the importance of anaerobic bacteria in SSI following spinal fusion.     

Aerobic and anaerobic microbiology of axillary hidradenitis suppurativa

A retrospective review of the microbiological and clinical data of 17 specimens obtained from axillary hidradenitis suppurativa (HS) over a period of 6 years was undertaken to study the aerobic and anaerobic microbiology of this condition. A total of 42 bacterial isolates (2.5 per specimen) were obtained, 12 aerobic or facultative (0.7 per specimen) and 30 anaerobic or micro-aerophilic (1.8 per specimen). Aerobic and facultative bacteria only were isolated in six (35%) cases, anaerobic bacteria only in seven (41%) and mixed aerobic and anaerobic bacteria in four (24%). The predominant aerobic bacteria were Staphylococcus aureus (six isolates), Streptococcus pyogenes (three) and Pseudomonas aeruginosa (two). The most frequently isolated anaerobes were Peptostreptococcus spp. (10), Prevotella spp. (seven), micro-aerophilic streptococci (four), Fusobacterium spp. (three) and Bacteroides spp. sensu stricto (three). This study highlights the polymicrobial nature and predominance of anaerobic bacteria in axillary HS and the need for antimicrobial thereby to reflect this.     

Microbiology of perianal cellulitis in children: comparison of skin swabs and needle aspiration

OBJECTIVE: To establish the aerobic and anaerobic microbiology of perianal cellulitis in children, comparing skin swab and needle aspirate methodology. METHOD: Swabs of involved skin and needle aspirates of cellulitis were studied for aerobic and anaerobic bacteria. RESULTS: Specimens obtained from 10 patients with perianal cellulitis showed bacterial growth. Polymicrobial aerobic-anaerobic flora was found in all skin surface cultures, where the predominate isolates were Peptostreptococcus spp., Escherichia coli, and alpha hemolytic streptococci. The number of isolates in needle aspirates varied between one and two. The predominant ones were E. coli (3), Peptostreptococcus spp. (3), Staphylococcus aureus (2), and Bacteroides fragilis group (2). Complete or partial concordance in microbiology between skin swabs and needle aspirates was present in six instances. In four instances, isolates recovered from needle aspirates were not isolated from the skin surface. CONCLUSIONS: This study demonstrates the diversity of aerobic and anaerobic organisms isolated from perianal cellulitis, and the superiority of needle aspirates in establishing the microbiology of the infection.     

Microbiology of liver and spleen abscesses

To study the aerobic and anaerobic microbiology of liver and spleen abscesses and correlate the results with predisposing factors, potential causes and routes of infection, clinical and laboratory data of 48 patients with liver abscesses and 29 with spleen abscesses treated between 1970 and 1990 were reviewed retrospectively. In liver abscesses, a total of 116 isolates (2.4 isolates/specimen) was obtained; 43 were aerobic and facultative species (0.9 isolates/specimen) and 73 were anaerobic species or microaerophilic streptococci (1.5 isolates/specimen). Aerobic bacteria only were isolated from 12 (25%) abscesses, anaerobic bacteria only from eight (17%), and mixed aerobic and anaerobic bacteria from 28 (58%); polymicrobial infection was present in 38 (79%). The predominant aerobic and facultative isolates were Escherichia coli (11 isolates), Streptococcus group D (8), Klebsiella pneumoniae (5) and Staphylococcus aureus (4). The predominant anaerobes were Peptostreptococcus spp. (18 isolates), Bacteroides spp. (13), Fusobacterium spp. (10), Clostridium spp. (10) and Prevotella spp. (4). There were 12 isolates of micro-aerophilic streptococci. S. aureus and beta-haemolytic streptococci were associated with trauma; Streptococcus group D, K. pneumoniae and Clostridium spp. with biliary disease; and Bacteroides spp. and Clostridium spp. with colonic disease. In splenic abscesses, a total of 56 isolates (1.9 isolates/specimen) was obtained; 23 were aerobic and facultative species (0.8 isolates/specimen), 31 were anaerobic species or micro-aerophilic streptococci (1.1 isolates/specimen) and two were Candida albicans. Aerobic bacteria only were isolated from nine (31%) abscesses, anaerobic bacteria from eight (28%), mixed aerobic and anaerobic bacteria from 10 (34%) and C. albicans in two (7%); polymicrobial infection was present in 16 (55%). The predominant aerobic and facultative isolates were E. coli (5 isolates), Proteus mirabilis (3), Streptococcus group D (3), K. pneumoniae (3) and S. aureus (4). The predominant anaerobes were Peptostreptococcus spp. (11 isolates), Bacteroides spp. (5), Fusobacterium spp. (3) and Clostridium spp. (3). S. aureus, K. pneumoniae and Streptococcus group D were associated with endocarditis, E. coli with urinary tract and abdominal infection, Bacteroides spp. and Clostridium spp. with abdominal infection and Fusobacterium spp. with respiratory infection.     

Mental illness in adults with fetal alcohol syndrome or fetal alcohol effects

PURPOSE: To investigate the aerobic and anaerobic microbiology of dacryocystitis. METHOD: Retrospective review of the 62 clinical and microbiologic records collected between 1980 and 1990. RESULTS: Aerobic or facultative bacteria were recovered in 32 cases (52%), anaerobic bacteria only in 20 cases (32%), mixed aerobic and anaerobic bacteria in seven cases (11%), and fungi in three cases (5%). A total of 94 organisms (1.5 per specimen), which included 56 aerobic or facultative anaerobic organisms, 35 anaerobic organisms, and three fungi, were recovered. The predominant aerobic and facultative bacteria were Staphylococcus aureus (15 isolates), Staphylococcus epidermidis (13 isolates), and Pseudomonas species (seven isolates). The most frequently recovered anaerobes were Peptostreptococcus species (13 isolates), Propionibacterium species (12 isolates), Prevotella species (four isolates), and Fusobacterium species (three isolates). The predominant fungus was Candida albicans (two isolates). Polymicrobial infection was present in 28 cases (45%). CONCLUSION: These data highlight the potential importance of anaerobic bacteria in dacryocystitis.     

Antimicrobial susceptibility of subgingival bacterial flora in dogs with gingivitis

The aerobic and anaerobic flora from gingival pockets of 49 dogs with severe gingivitis and periodontitis were cultured. The susceptibility of each isolate to four antimicrobial agents currently approved for veterinary use in the USA (amoxicillin-clavulanic acid; clindamycin; cefadroxil; and enrofloxacin) was determined. Amoxicillin-clavulanic acid (Clavamox Pfizer Animal Health) had the highest in-vitro susceptibility against all isolates (96%), all aerobes (94%) and all anaerobes (100%) tested. For gram-negative aerobes, enrofloxacin (Baytril, Bayer Corp.) had the highest in-vitro susceptibility activity. For bacteria associated with treatment of gingivitis, which typically are mixed aerobic/anaerobic and gram-positive/gram-negative organisms, the antimicrobial of choice for clinical use based on these susceptibility tests is amoxicillin-clavulanic acid.     

Anaerobes and fungi in chronic suppurative otitis media

Microbiology of 102 ears with chronic suppurative otitis media was studied for aerobes, anaerobes, and fungi. Forty-four percent were pure cultures, 33.3% were mixed, and 18.6% had no growth. Seventy-four percent were aerobes, 25% fungi, and only 0.9% anaerobes. Pseudomonas aeruginosa (22.5%) was the most common isolate, followed by Staphylococcus aureus and the Aspergillus species. The possible reasons for low yield of anaerobes and the pathogenic roles of anaerobes and fungi in chronic suppurative otitis media are discussed. It is advocated that in investigating pathogenic organisms in chronic suppurative otitis media, requests should include anaerobes and fungi.     

Intraocular pressure in snorkling and diving (author''s transl)]

The in vitro susceptibility of 145 anaerobic clinical isolates and 96 gram-positive aerobic clinical isolates to josamycin, a new macrolide antibiotic, was studied using the agar dilution technique. Ninety-five of the aerobes were susceptible to 1.56 mug or less of josamycin per ml. The median minimal inhibitory concentration of these organisms was 相似文献   

Aerobic and anaerobic microbiology of empyema. A retrospective review in two military hospitals

The microbiology and clinical features of empyema were studied retrospectively in 197 patients whose specimens yielded bacterial growth after inoculation for aerobic and anaerobic bacteria. Three hundred forty-three organisms (216 aerobic or facultative and 127 anaerobic organisms) were isolated. Aerobic bacteria were isolated in 127 (64 percent) patients, anaerobic bacteria in 25 (13 percent), and mixed aerobic and anaerobic bacteria in 45 (23 percent). The predominant aerobic or facultative organisms were Streptococcus pneumoniae (70 isolates), Staphylococcus aureus (58), Escherichia coli (17), Klebsiella pneumoniae (16), and Haemophilus influenzae (12). The predominant anaerobes were pigmented Prevotella and Porphyromonas species (24), Bacteroides fragilis group (22), anaerobic cocci (36), and Fusobacterium species (20). beta-Lactamase-producing organisms were recovered in 49 (38 percent) of 128 tested specimens. These included all 42 tested S aureus and 15 B fragilis group, 4 of 9 K pneumoniae, 3 of 9 H influenzae, 3 of 8 pigmented Prevotella and Porphyromonas species, and 2 of 6 E coli. Most patients from whom S pneumoniae and H influenzae were recovered had pneumonia, and most patients with S aureus had pneumonia, aspiration pneumonia, and lung abscesses. The recovery of anaerobic bacteria was mostly associated with the concomitant diagnosis of aspiration pneumonia, and lung, subdiaphragmatic, dental, and oropharyngeal abscesses. These data highlight the importance of anaerobic bacteria in selected cases of empyema.     

Otitis media: microbiology and management

Otitis media (OM) is a common childhood disease and one that can cause significant morbidity. A knowledge of the pathogens responsible for OM can assist in the selection of the most appropriate treatment regimen and can minimize complications that may require surgery. The microbiology of acute, serous, and chronic OM is reviewed. The major organisms recovered from about three quarters of acute OM and half of serous OM cultures are Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis. Streptococcus pyogenes, anaerobic cocci, and viruses can each be isolated in less than 5% of the patients with acute OM. The predominant organisms isolated from chronic OM are Staphylococcus aureus, Pseudomonas aeruginosa, and anaerobic bacteria. The predominant anaerobes are gram-positive cocci, pigmented Prevotella and Porphyromonas sp, Bacteroides sp, and Fusobacterium sp. Many of the aerobic and anaerobic organisms causing OM can produce beta-lactamase, rendering them resistant to many of the penicillins. The appropriate surgical and medical therapies for acute, serous, and chronic otitis media are discussed.     

Level of redox potential as a possible contributing influence in the pathogenicity of oral anaerobes

Dental plaque anaerobes may be associated with the etiology of periodontal disease. This has created an interest in the potential pathogenicity of oral anaerobes. We compared the metabolic activity of anaerobic corynebacteria (C. parvum, C. anaerobium) and corresponding aerobic species (C. diphtheriae, C. xerosis). The anaerobes exhibited lower levels of RNA synthesis, ranging from 5 to 10 fold over the aerobes. We further examined these anaerobes, plus Actinomyces naeslundi N16 (isolated from the anaerobic region of periodontally-diseased tissues), for the influence of redox potential on RNA level and antigenic function. Notable increases in RNA were found at specific Eh levels; the extent and direction of the changes varied with the different organisms. This environmental feature appeared to effect corresponding changes in agglutinability and PCA reactivity with antisera against the anaerobes cultured at different redox potentials. For example, while antisera against certain organisms (C. parvum, A. naeslundi) cultured under the most reuced conditions showed an intense PCA reaction, other antisera against the same organism cultured under less reduced conditions were non-reactive. Hence, alterations in redox potential may lead to alteredetabolism and to altered antigencity. Our results imply such a microbial response to environmental stress.     

Efficacy of cefditoren pivoxil in the treatment of acute otitis media due to benzylpenicillin-insensitive Streptococcus pneumoniae

Clinical and bacteriological studies were carried out on cefditoren pivoxil (CDTR-PI) granule in infantile purulent acute otitis media treated at general practice settings and the following findings were obtained: 1. Two hundred forty eight strains were isolated from 210 patients, almost all of which (81.1%) harbored the following two strains: Streptococcus pneumoniae (42.3%) and Haemophilus influenzae (38.8%). Among S. pneumoniae, benzylpenicillin (PCG)-insensitive S. pneumoniae, (PISP) or PCG-resistant S. pneumoniae (PRSP) was 36.2%, corresponding to 15.3% of all the isolates and found in 18% of all patients. 2. The bacteria in the middle ear discharge and the nasopharyngeal swabs were correlated with conformity rate of more than 80% with regard to Streptococcus pyogenes, S. pneumoniae and H. influenzae but no Staphylococcus aureus was detected simultaneously from the two sources in any of the patients. S. aureus and coagulase-negative staphylococci (CNS) were considered to be contaminants that were originated from the external auditory meatus at the time of sampling. 3. Frequencies of isolation of S. pneumoniae from different age groups were higher in a lower age group between 0 and 4 years and those of PISP or PRSP had the similar tendency. 4. Antibacterial activities were determined for CDTR and related oral antibiotics against the strains of S. pneumoniae and H. influenzae as representative isolates. CDTR had stronger antibacterial activities against both bacteria than the reference antibiotics. CDTR was found to be transferred into the otorrhea at a mean concentration of 0.58 micrograms/ml after single administration of CDTR-PI granule formulation at 3 mg(potency)/kg. 5. As for bacterial eradication efficacies in the middle ear cavity and the nasopharynx, eradication rates were higher than 80% in the middle ear cavity in all cases without large differences among bacterial species but eradication rate of PISP was 30% in the nasopharynx, and it was significantly lower than those of PSSP and other bacteria. 6. In view of clinical effectiveness, the efficacy rate was 89.4% and bacteriological effects was 92.2%; in view of safety, adverse reactions were; observed in 9.5% and the rate of usefulness was 89.4%. 7. From above-stated results, CDTR-PI was considered as a useful oral antibiotic for infantile acute otitis media including PISP infections.     

Observations on health care issues in the former Soviet Union

Bacteriologic samples from 31 young men were cultured quantitatively for aerobes and anaerobes; these samples included 31 specimens of tonsils (16 infected and 15 healthy), 16 specimens from pericoronal pockets of lower third molars (11 infected and 5 symptom-free), and 6 postoperative specimens from lower-third-molar extraction sockets. Anaerobes were isolated more often from infected third molars than from infected tonsils (14.5 isolates vs. 8.4 isolates, respectively; P < .001). Infected tonsil samples contained significantly more anaerobic species if an adjacent partly erupted lower third molar was present rather than absent (10.3 isolates vs. 6.9 isolates, respectively; P < .05). Eubacterium aerofaciens, Clostridium species, Peptostreptococcus micros, and Prevotella oris were frequently isolated. Streptococcus salivarius was found more frequently in tonsillar specimens, whereas Corynebacterium species, Prevotella denticola, Capnocytophaga species, Peptostreptococcus anaerobius, and Lactobacillus species were more common in pericoronal pocket samples. Thus, partial eruption of lower third molars increases the number of anaerobic bacterial species on tonsils and many species can be isolated simultaneously from both tonsils and lower third molars.     

Josamycin and rosamicin: in vitro comparisons with erythromycin and clindamycin

The macrolide antibiotics josamycin and rosamicin were compared in vitro with erythromycin for activity against Staphylococcus aureus, S. epidermidis, and enterococci and with clindamycin for activity against a variety of anaerobic organisms. Rosamicin and erythromycin were similar in activity and superior to josamycin against aerobic cocci. Most isolates of S. aureus (96%), S. epidermidis (79%), and the enterococci (87%) were inhibited by 1.56 mug of either of the new macrolide compounds per ml. Clindamycin was the most active compound against the anaerobic organisms.     

Significance of a diastolic notch in the uterine artery flow velocity waveform induced by uterine embolisation in the pregnant ewe

OBJECTIVE: To determine whether water exposure causes middle ear contamination in patients with collar button tympanostomy tubes (TTs). METHOD AND DESIGN: An in vitro model of a human head that contained an auricle, external auditory canal, tympanic membrane with TT, middle ear, eustachian tube, and mastoid cavity was developed. Two electrodes connected to an external ohmmeter resided in the middle ear to detect water entry. The model was tested with 4 types of water exposure: showering, bathing, hair rinsing, and swimming. Statistical analysis was performed by the Fisher exact test. MAIN OUTCOME MEASURES: A positive test result corresponded to water entering the middle ear via the TT, confirmed by a resistance reading of zero on the ohmmeter. A negative test result indicated no change in the initial high resistance reading. RESULTS: No positive test results were obtained for showering (0 of 60 tests), hair rinsing (0 of 60 tests), or head submersion (12.7 cm) in clean tap water (0 of 60 tests). Ten positive test results were obtained for head submersion in soapy water (10 of 97 tests), which was statistically different from clean water (P< or =.007). Swimming pool depths of 30, 45, 60, and 75 cm elicited positive test results in 2 of 16, 3 of 18, 2 of 20, and 11 of 20 tests, respectively. A higher incidence of water entry into the middle ear occurred at depths of more than 60 cm (P< or =.001). No statistical difference between depths of 60 cm or less occurred (P= .88). CONCLUSIONS: Showering, hair rinsing, and head submersion in clean tap water do not promote water entry into the middle ear. Submersion in soapy water increases the probability of water contamination. Pool water infrequently enters the middle ear with head submersion, but the incidence increases with deeper swimming (>60 cm). These data provide further evidence that many water precautions frequently advised in patients with TTs are unnecessary.     

Is gastrin trophic? Gastrin/ gastrin receptor "knockout" mice confirm the old hypothesis

Cerumen is the product of the secretion of the sebaceous, ceruminous or apocrine glands together with cells exfoliated from the cornified stratum of the epithelium of the external auditory canal (EAC). In the present study we identified and quantified common flora of human cerumen. The mean count obtained was 10(6) microorganisms per ml of cerumen suspension. In 24 pools of cerumen (33.3 per cent) the isolates were monomicrobial, Staphylococcus epidermidis (12), Corynebacterium spp (10), Staphylococcus aureus (1) and Streptococcus saprophyticum (1). In 48 pools (66.6 per cent) we found polymicrobial isolates. The most commonly isolated bacteria in these polymicrobial isolates were S. epidermidis (35) and Corynebacterium spp. (43). It is noteworthy that there were isolates of Candida albicans in three cases; in one case of Pseudomonas stutzeri, in one case of Pseudomonas aeruginosa, and, on seven occasions, of S. aureus. The organisms isolated as common bacterial components of human cerumen in our experience were similar to those found by other authors. However, the mean count was much higher. This could be related to climatic conditions and to the length of time the cerumen had remained in the external auditory canal.     

In vitro evaluation of activities of nitazoxanide and tizoxanide against anaerobes and aerobic organisms

The antibacterial activities of nitazoxanide and its main metabolite, tizoxanide, were tested against a broad range of bacteria, including anaerobes. Metronidazole, amoxicillin, amoxicillin-clavulanic acid, piperacillin, cefoxitin, imipenem, and clindamycin were used as positive controls. MICs were determined by reference agar dilution methods. The 241 anaerobes were all inhibited by nitazoxanide, with the MICs at which 90% of isolates are inhibited (MIC90S) being between 0.06 and 4 mg/liter with the exception of those for Propionibacterium species, for which the MIC90 was 16 mg/liter. The MIC90s of nitazoxanide were 0.5 mg/liter for the Bacteroides fragilis group (80 strains), 0.06 mg/liter for Clostridium difficile (21 strains), and 0.5 mg/liter for Clostridium perfringens (16 strains). Metronidazole showed a level of activity comparable to that of nitazoxanide except against Bifidobacterium species, against which it was poorly active, and Propionibacterium species, which were resistant to metronidazole. The other antibiotics showed various levels of activity against anaerobes, with imipenem along with nitazoxanide being the most active agents tested. Tizoxanide was less effective than nitazoxanide except against the B. fragilis group, against which its activity was similar to that of nitazoxanide. Under aerobic conditions, nitazoxanide demonstrated poor activity against members of the family Enterobacteriacae and Pseudomonas, Staphylococcus, and Enterococcus species. The same results were obtained when culture was performed under anaerobic conditions with the notable exception of the results against Staphylococcus aureus. The MICs of nitazoxanide were in the range of 2 to 4 mg/liter for 34 clinical isolates of S. aureus, 12 of which were methicillin resistant, while tizoxanide was not effective.