Anaerobic Plate Research Articles

Rapid method for selective enumeration ofBifidus essensisin ACTIVIA yogurts

The aim of this study was to develop simple, rapid and reliable methods for the selective determination of Bifidus essensis from ACTIVIA (Danone) yogurts. The methods are based on a modified MRS medium (B-broth), which does not contain inhibitory additives. The sugar source of the medium is maltose, which is metabolized by the bifidobacteria applied in the probiotic products, and not by the normal microflora of yogurt ( Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus ). The redox potential of the medium was reduced with cysteine-HCl. Due to its reduced redox potential, the new bouillon is suitable for aerobic cultivation of bifidobacteria, while in agar form it needs anaerobic incubation. In bouillon form (MPN method) the incubation time is only 2 days compared to the 5-day requirement of the classical anaerobic plate counting methods. The B-broth in diluted form was successfully used in a RABIT (Don Whitley) equipment for selective impedimetric determination of bifidobacteria i...

Use of Carbon Monoxide Combined with Carbon Dioxide for Modified Atmosphere Packaging of Pre- and Postrigor Fresh Pork Sausage To Improve Shelf Life

Fresh pre- and postrigor pork sausage patties were manufactured in the Iowa State University Meat Laboratory and packaged either in modified atmosphere (MAP) with 0.4% carbon monoxide (CO) and 99.6% carbon dioxide (CO2) or on foam trays overwrapped with oxygen-permeable film (OW). Packages were stored at 2 to 4°C under fluorescent lights for up to 31 days. Aerobic, anaerobic, and psychrotrophic plate counts, raw and cooked color, purge, and lipid oxidation were measured during storage. Results indicated that both pork sausage products in MAP had lower aerobic and psychrotrophic counts and less lipid oxidation throughout storage (P < 0.05). Raw color of both products in MAP was redder than the OW patties (P < 0.05), but the prerigor pork sausage in MAP benefited more from the CO atmosphere in terms of raw color than the postrigor pork sausage in MAP. Cooked color of the prerigor pork sausage in MAP was significantly redder than cooked color of the postrigor pork sausage. Both pork sausage products in MAP were also lighter (L* value) than the OW patties for raw and cooked color. Therefore, the combination of CO and CO2 in MAP was beneficial in extending the shelf life of preand postrigor fresh pork sausage by reducing aerobic and psychrotrophic microbial growth and improving oxidative stability and color, compared to conventional OW packaging. However, increased purge, increased anaerobic growth, and changes in cooking behavior were also observed for the products in MAP during storage (P < 0.05).

Clostridium tertium isolated from gas gangrene wound; misidentified as Lactobacillus spp initially due to aerotolerant feature

Clostridium tertium has been increasingly reported as a human pathogen. This organism is an aerotolerant Gram-positive rod that is often mistaken for other organisms, such as Lactobacillus or Bacillus species. We describe a case of a patient with a history of intravenous drug use presenting to UCLA-Olive View Medical Center with gas gangrene of both upper extremities. The organism was initially misidentified as a Lactobacillus species on aerobic culture plates. However, terminal spore formation was detected in this isolate on a sub-cultured anaerobic culture plate and this isolate was confirmed as C. tertium biochemically and genetically by 16S rDNA sequencing. Additional DNA cloning libraries made from the formalin-fixed specimen revealed Peptoniphilus species and an uncultured Clostridium clone, but not C. tertium. C. tertium might be a causative organism of gas-producing myonecrosis but such an association has never been described. Clinicians should be aware of the phenomenon of aerotolerance of some anaerobes and need to clarify the identification of organisms if the clinical picture does not fit the isolated organism.

A six-month audit of the isolation of Fusobacterium necrophorum from patients with sore throat in a district general hospital

Fusobacterium necrophorum is an obligate anaerobe believed to be a member of the normal flora of the human oropharangeal and urogenital tract. It has been associated with deep-seated infections and was first described in 1936 by Lemierre, a French microbiologist. There is now strong evidence to suggest that it is also a cause of recurrent sore throat and persistent sore throat syndrome (PSTS) without leading to full systemic infection. It is considered to be the second most common cause of sore throat after group A β-haemolytic streptococci. This study was performed over a six-month period (October 2004 to March 2005) at the Eastbourne District General Hospital. All throat swabs received in the laboratory are cultured routinely for haemolytic group A streptococci and pathogenic Corynebacteria spp. During the study period an extra fastidious anaerobic blood agar plate with neomycin was inoculated, with a 30 µg vancomycin disc placed at the junction of the second and third streaks. This was examined after 48 h for the presence of F. necrophorum. A total of 1157 swabs were processed during the study period: 156 were positive for haemolytic group A streptococci, 57 were positive for F. necrophorum, 47 for group C haemolytic streptococci, nine for group G haemolytic streptococci, and one was positive for C. ulcerans. Patient age ranged from less than a year old to 88. The majority of F. necrophorum isolates were from patients in the 11–25 age group, with an isolation rate of 9.48% (44/464). This age group accounted for 40% (464/1157) of the swabs received during the study period and 77% (44/57) of these were positive for F. necrophorum. Group A haemolytic streptococci showed an overall isolation rate of 13.5%, with peaks of 23% in the 0–10 and 26–35 age ranges. Together, these two organisms were responsible for 18.4% (213/1157) of all throat infections in this study. The results presented here indicate that F. necrophorum is second to group A haemolytic streptococci as a cause of sore throat, especially in the young adult, and introduction of routine culture should be considered.

Protease-Activated Receptor-2 Activation: A Major Role in the Pathogenesis of Porphyromonas gingivalis Infection

Protease-Activated Receptor-2 Activation: A Major Role in the Pathogenesis of Porphyromonas gingivalis Infection

Contaminación microbiológica y actividad antimicrobiana del azúcar de caña cristalizado sobre algunos agentes de interés médico en Costa Rica

Microbiological contamination and antimicrobial activity of cristalised cane sugar on some medically important microorganisms in Costa Rica. Unrefined cristalised cane sugar, obtained after the filtration and evaporation of sugar cane juice, is a nutritional product of traditional consumption in Costa Rica and other Neotropical countries. It has been used in the topic treatment of infected wounds, with satisfactory results even with some antibiotic-ressistant bacteria. We studied the microbiological quality of 50 commercial samples. The analyses included total aerobic and anaerobic bacteria plate count; aerobic and anaerobic spore count; mold and yeast count; total and fecal coliforms; and presence of Clostridium botulinum. The antimicrobial effect was tested for Staphylococcus aureus (ATCC 25923), S. epidermidis (UCR 2902), Pseudomonas aeruginosa (ATCC 9027), Escherichia coli (ATCC 25922), Salmonella enteritidis (ATCC 13076), Listeria monocytogenes (ATCC 19116) and Aspergillus niger (Asni 06). Most of the samples (76%) presented counts lower than 100 CFU/g especially for sporulated forms (90% lower than 20 CFU/g), the mold and yeast count was higher (38% higher than 10(2) CFU/g), demonstrating the importance of these microorganisms in the spoilage of the product; 76% of the samples presented fecal contamination; C. botulinum was not isolated with the methodology employed. No inhibitory effect was observed for A. niger, but all samples han an inhibitory effect over the other species, especially for P. aeruginosa and S. aureus.

Shelf-life and Microbiological Profiler of Chicken Wing Products Following Sous vide Treatment

Chicken wings were vacuum-packaged and cooked (sous vide) at 75 and 90 C until the internal o temperature reached 73.8 C was reached. The cooked samples were stored at 2 and 7 C, separately. The o o TBA values, aerobic plate count, aerobic and anaerobic plate counts and Warner-Bratzler (WB) shear force of the samples were evaluated weekly for 7 wk. The sous vide treatment chicken wings had lower TBA values, aerobic and anaerobic plate counts throughout the 7 wk of storage when compared with the control. The sous vide treatment did not affect the WB shear force of chicken wings. At 2 C, the sous vide cooked o chicken wings had a shelf life of at least 7 wk. Results demonstrate that sous vide treatment was an effective method to prevent lipid oxidation during storage and enhance shelf life of chicken wing products.

Inhibition of Nonproteolytic, Psychrotrophic Clostridia and Anaerobic Sporeformers by Sodium Diacetate and Sodium Lactate in Cook-in-Bag Turkey Breast ,

A nonproteolytic, psychrotrophic Clostridium isolate, designated strain OMFRI1, was recovered from cook-in-bag turkey breasts (CIBTB) that displayed an intense pink discoloration and an off-odor following extended refrigerated storage. The viability of strain OMFRI1 in CIBTB containing sodium diacetate (at 0, 0.25, and 0.5%) and/or sodium lactate (at 0, 1.25, and 2.5%) was subsequently evaluated. Raw CIBTB batter was inoculated with 9 to 30 spores of strain OMFRI1 per g, vacuum packaged, cooked to an instantaneous internal temperature of 71.1°C, chilled, and incubated at 4°C for up to 22 weeks. In the absence of food-grade antimicrobial agents, spoilage (i.e., an off-odor) occurred within 6 weeks, and anaerobic plate counts reached 6.6 log10 CFU/g. The CIBTB containing sodium diacetate (0.25%) and that containing sodium lactate (1.25%) required 12 weeks for spoilage to occur and for anaerobic plate counts to reach 7.0 and 6.0 log10 CFU/g, respectively. When sodium diacetate (0.25%) and sodium lactate (1.25%) were used in combination, no off-odor was detected and anaerobic plate counts did not exceed 2.3 log10 CFU/g over 22 weeks of storage at 4°C. In related experiments, sodium diacetate (at 0, 0.25, and 0.5%), sodium lactate (at 0, 1.25, and 2.5%), and combinations of both ingredients were evaluated in uninoculated CIBTB incubated at 25°C for up to 22 days. In the absence of antimicrobial agents and in CIBTB containing sodium diacetate (0.5%), spoilage occurred within 8 days and anaerobic plate counts reached 6.8 and 6.6 log10 CFU/g, respectively. Samples of CIBTB containing sodium lactate (2.5%) showed signs of spoilage within 22 days, and anaerobic plate counts for these samples ranged from ≤1.0 to 6.3 log10 CFU/g. In CIBTB containing both sodium lactate (2.5%) and sodium diacetate (0.25%), spoilage was not evident and anaerobic plate counts were ≤1.0 log10 CFU/g within 22 days. These data validate the efficacy of sodium lactate and sodium diacetate in extending the shelf life of CIBTB.

COMPARISON OF CULTURE OF SYNOVIAL FLUID, PERIPROSTHETIC TISSUE AND PROSTHESIS SONICATE FOR THE DIAGNOSIS OF KNEE PROSTHESIS INFECTION

Background. Synovial fluid and periprosthetic tissue specimens are the standard specimens cultured for the diagnosis of prosthetic joint infection (PJI). We hypothesize that ultrasonication of the explanted prosthesis may improve diagnosis of PJI by dislodging biofilm bacteria from the prosthesis surface and improve the sensitivity and specificity of diagnosis of PJI. Methods. Included were patients undergoing knee prosthesis exchange for septic or biomechanical failure and have not received antimicrobial therapy in the last 2 weeks prior specimen collection. Cultures of synovial fluid and periprosthetic tissue specimens were performed per the usual clinical practice. Additionally, explanted joint components were sonicated for 5 minutes at frequency 40 kHz in sterile Ringer’s solution; aliquots of 0.5 ml sonicate were plated onto five aerobic and five anaerobic blood agar plates, and incubated at 37 °C and examined for the next seven days. The number and identity of each colony morphology was recorded. Results. 35 patients undergoing knee replacement have been studied (24 for aseptic biomechanical failure and 11 for suspected PJI). In patients with PJI, coagulase-negative staphylococci (7 cases), Corynebacterium spp. (2 cases), Staphylococcus aureus (1 case), and viridans group streptococcus (1 case) were recovered. Culture sensitivity and specificity were for synovial fluid 88% and 100%, for periprosthetic tissue 83% and 81%, and for explant sonicate 91% and 100%, respectively. In sonicate cultures higher numbers of microorganisms than in periprosthetic tissue cultures were consistently detected. Conclusions. Using synovial fluid, periprosthetic tissue, and explant sonicate cultures, 12%, 17% and 9% of PJI were missed, respectively. Explant sonicate cultures were the most sensitive with respect to the diagnosis of PJI, indicating that explant ultrasonication may improve bacterial recovery. In sonicate cultures, infecting organisms were detected in high numbers, typically concentrated on only one of the prosthetic components. These findings indicate that explant ultrasonication may improve bacterial recovery and support the importance of biofilms in, and the focal nature of, PJI.

Comparative Evaluation of Anoxomat and Conventional Anaerobic GasPak Jar Systems for the Isolation of Anaerobic Bacteria

Objectives: To evaluate the performance of the Anoxomat, in comparison with the conventional anaerobic GasPak jar system, for the isolation of obligate anaerobes. Method: Anoxomat, model WS800, and anaerobic GasPak jar system (Oxoid) were evaluated. Anoxomat system utilized a gas mixture of 80% N₂, 10% CO₂ and 10% H₂, while the GasPak used a gas mixture of 90% H₂ and 10% CO₂. An anaerobic indicator within the jars monitored anaerobiosis. A total of 227 obligate anaerobic bacteria comprising 116 stock strains, 5 ATCC reference strains and 106 fresh strains, representing different genera, were investigated for growth on anaerobic agar plates and scored for density, colony sizes, susceptibility zones of antibiotic inhibition and the speed of anaerobiosis (reducing the indicator). Results: The results demonstrate that the growth of anaerobic bacteria is faster inside the Anoxomat jar than in the anaerobic GasPak jar system. Of the 227 strains tested, the colonies of 152 (67%) were larger (by size range of 0.2–2.4 mm) in the Anoxomat at 48 h than in the GasPak jar compared with only 21% (range 0.1–0.3 mm) that were larger in the GasPak than in the Anoxomat. The remaining 12% were equal in their sizes. There was no measurable difference in the colony sizes of the reference strains. The Porphyromonas asaccharolytica strains failed to grow within the GasPak system but grew inside the Anoxomat. With the Anoxomat, anaerobiosis was achieved about 35 min faster than in the GasPak system. The density of growth recorded for 177 (78%) strains was heavier in the Anoxomat than in the GasPak jar. The zones of inhibition of the antibiotics tested were not different in the two systems. Conclusion: The Anoxomat system provided superior growth, in terms of density and colony size, and achieved anaerobiosis more rapidly. Evidently, the Anoxomat method is more reliable and appears to support the growth of strict anaerobes better.

Screening and selection of Lactobacillus strains for use as adjunct cultures in production of semi-hard cheese.

Thirty-three Lactobacillus strains were tested as adjuncts in a cheese model system. Eighteen strains originated from cheese (nine Lactobacillus spp. and nine Lb. paracasei/casei) and 15 from human intestinal mucosa (11 Lb. rhamnosus; three Lb. paracasei; one Lb. plantarum). Model cheeses weighing 120 g were made of cheese grains from full-scale production of washed curd semi-hard cheese (Herrgård). The model system was reproducible and similar to full-scale production with respect to moisture, salt content, pH and microbial flora. The model cheeses were sampled for aerobic and anaerobic plate count and viable counts of Lactobacillus and Lactococcus. The presence of adjuncts in the model cheeses was confirmed by typing isolates with Randomly Amplified Polymorphic DNA (RAPD). The sensory properties of model cheeses were described. In a first trial 23 of the 33 adjuncts were re-isolated from the corresponding model cheeses after 9 or 13 weeks. Adjuncts of Lb. paracasei were re-isolated more frequently than adjuncts of Lb. rhamnosus. Nine strains were selected, on the basis of their ability to grow and be a dominating part of the microflora of model cheese with interesting sensory properties. These strains were further studied together with two commercial cultures. The sensory influences on model cheeses of six of the adjuncts were confirmed, and flavour scores were in the range of 2.9-7.1 for model cheeses with different adjuncts while the control had a flavour score of 5.6 (0-10 scale). Survival and growth of seven out of the nine strains correlated with the results of the first trial. Growth and influence on flavour of four adjunct cultures were confirmed in experimental cheese manufactured in a 400-1 open vat.

A semiconducting metal-oxide array for monitoring fish freshness

An array of semiconducting metal-oxide (SMO) chemiresistive sensors can quantitatively measure the freshness of Atlantic salmon ( Salmo salar), haddock ( Melanogrammus aeglefinus), and Atlantic cod ( Gadus morhua). A variety of SMO films were tested, including films containing oxides of copper and tin, and commercially available tin-based SMO films. Analytical testing of the fish samples was performed in conjunction with SMO sensor testing of the volatile gases emitted from the degrading fish. Testing included the use of a sensory evaluation panel and tests incorporating amine colorimetric methods, pH analyses, and bacterial aerobic and anaerobic plate counts. Sensory analysis, trimethylamine (TMA) content, pH, and aerobic and anaerobic plate counts provided results that correlated well with each other and with SMO sensor results. A radial basis function (RBF) neural network was designed and used to classify the day of fish degradation (1–15) from the SMO sensor array response.

Effect of dietary fish oil on fatty acid composition, lipid oxidation and sensory property of chicken frankfurters during storage

Broilers fed with three levels of fish oil (0, 2 and 4%) for 6 weeks were used in the manufacture of chicken frankfurters. The meat samples were vacuum-packed and stored at 0°C for 0, 10, 20 and 30 days. Cooking yield, proximate and fatty acid composition, lipid oxidation, microbial and sensory properties of the meat products were measured. Cooking yield, moisture, fat, protein, ash and cholesterol contents of frankfurters were not affected ( P>0.05) by levels of dietary fish oil. Frankfurters processed from chickens fed diets enriched with 2 and 4% of supplemental fish oil had a higher ( P<0.05) level of n-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid), but had a lower level of n-6 fatty acids ( P<0.05) than the controls (0% fish oil). TBA values and pH values of meat samples were not affected ( P>0.05) by levels of supplemental fish oil in the diets, however, pH values of the vacuum-packaged chicken frankfurters decreased ( P<0.05) as the storage time increased. No differences ( P>0.05) in total anaerobic plate counts were observed among the fish oil treatments during storage. Supplementation of 2 and 4% fish oil in the diets did not increase ( P>0.05) the intensity of fishy flavor in chicken frankfurters.

Pleural Effusion Due toCorynebacterium Propinquumin a Patient with Squamous Cell Carcinoma

Pleural Effusion Due to<i>Corynebacterium Propinquum</i>in a Patient with Squamous Cell Carcinoma

The predominant Actinomyces spp. isolated from infected dentin of active root caries lesions.

Actinomyces are Gram-positive pleomorphic rods (GPPR) which form a large proportion of the oral microflora of all mammals. They have been implicated in root caries, although their role in dental caries initiation and progression is not well-understood. Many studies have focused on Actinomyces naeslundii, but few reports have documented other members of the GPPR. Therefore, we investigated the GPPRs isolated from infected dentin of active root caries lesions (n = 9) to determine which species were the most frequently isolated. The GPPR were isolated under both aerobic and anaerobic conditions and identified by biochemical and physiological tests to the species level according to the new taxonomy. Of 654 GPPR isolates investigated, 607 were identified as belonging to the genus Actinomyces. Of these, 242 were identified as A. israelii, 225 as A. gerencseriae, 109 as A. naeslundii, 15 as A. odontolyticus, and 13 as A. georgiae. Individual strains of A. israelii (n = 56) and A. gerencseriae (n = 46) were also investigated at the DNA level by means of Repetitive Extragenic Palindromic polymerase chain-reactions (REP-PCR) for the study of clonal diversity. Although only a small number of isolates was investigated, REP-PCR showed that the genotypes of both A. gerencseriae and A. israelii populations were heterogeneous within individual root caries lesions. A. gerencseriae and A. israelii strains from the same lesions did not share the same REP-PCR patterns, showing the robustness of the identification scheme. A significantly greater proportion of A. gerencseriae was isolated from the aerobic plates (p < 0.05), while the proportion of A. israelii was significantly (p < 0.05) greater from anaerobic plates. The role of individual Actinomyces spp. in the root caries process remains unclear, since various populations of GPPRs were isolated from individual active root caries lesions.

Evaluation of Botulinal Toxin Production in Packaged Fresh-Cut Cantaloupe and Honeydew Melons

The ability of Clostridium botulinum to produce toxin on cubed, packaged melons was investigated relative to microbial spoilage at various incubation temperatures and in different packaging systems. Freshly cut cubes (approximately 2.5 cm3) of cantaloupe and honeydew melons were surface inoculated with a 10 strain mixture of proteolytic and nonproteolytic spores of C. botulinum (10 to 15 cubes per package; approximately 100 total spores per package). To initially evaluate toxin production and spoilage in a passively modified atmosphere, melon cubes were loosely packaged in air in polyethylene pouches, sealed, and incubated at 7 or 15°C for up to 21 days. At various sampling intervals, samples were tested for headspace oxygen and carbon dioxide levels, pH, presence of botulinal toxin, aerobic and anaerobic plate counts, and counts of yeasts and molds. During incubation, headspace oxygen levels decreased, headspace carbon dioxide levels increased, aerobic and anaerobic plate counts increased, and the pH remained constant or decreased slightly. Botulinal toxin was not detected in any cantaloupe samples or in honeydew samples incubated at 7°C. Botulinal toxin was detected in some honeydew samples at 15°C after 9 days of incubation, but the toxic honeydews were severely spoiled and considered organoleptically unacceptable. A similar second experiment was performed in which half of the melon cubes were treated with UV light to inactivate vegetative organisms before packaging, and these were incubated at 7, 15, or 27°C. In this second experiment, toxin production occurred in the UV-treated samples at 15°C with gross spoilage and at 27°C with only marginal spoilage. These data indicate that inhibition of spoilage organisms with UV light could result in botulinal toxin formation in packaged melons before overt spoilage.

Comparison of aerobic and anaerobic methods for the microbiological monitoring of chilled packaged meat during storage

Aerobic and anaerobic plate counts were compared for routine monitoring of the microflora, dominated by lactic acid bacteria, developing on vacuum- and carbon dioxide-packaged raw meat during chilled storage. No statistical differences were observed between aerobic and anaerobic enumerations, made on plate count and blood agar plates, of the microflora developing on beef striploins packaged under vacuum or carbon dioxide during 14 weeks' storage at 0 degree C. With both techniques the spoilage microflora development differed between the two packaging regimes. The results indicate that there is no necessity for aerobic plate counts to be replaced by anaerobic plate counts in the routine microbiological examination of the spoilage microflora developing on chilled meats packaged under anoxic modified atmospheres.

Monthly changes in the rate of recovery of penicillin-resistant organisms from children.

Monthly changes in the rate of recovery of penicillin-resistant organisms from children.

A COMPARISON STUDY BETWEEN OXYRASE ANAEROBIC AGAR PLATES AND CONVENTIONAL ANAEROBIC CHAMBER FOR THE ISOLATION AND IDENTIFICATION OF ANAEROBIC BACTERIA FROM CLINICAL INFECTIONS

Misplaced confidence in the broad‐spectrum antibiotics, increased resistance among previously predictable anaerobic antibiograms, and the push to maximize productivity of available space and downsizing trends has created a need for a simplified cost‐effective, and superior method for the isolation and identification of anaerobic bacteria. In this study, the Oxyrase anaerobic plate system which requires no extraneous apparatus to create an anaerobic environment was compared to an anaerobic chamber in the isolation of anaerobic bacteria from 212 consecutive wound specimens. Brucella blood agar and KVL agar plates were used in this comparison study. RapID ANA II, AP120A, special potency disks, and GLC were used for identification. Of the 212 specimens cultured, 87 yielded anaerobic bacteria comprising 182 strains. Thirty‐nine strains failed to grow in the anaerobic chamber but grew on the OxyPlates(TM). These strains were predominantly Peptostreptococcus species (28%), Eubacterium species (20%), and Propionibacterium species (20%). Fourteen strains failed to grow on the OxyPlates, but grew in the anaerobic chamber. No trend was noted and all organisms in this category grew on the OxyPlates from other specimens. In conclusion, the Oxyrases anaerobic plate system appears to be an excellent alternative to the conventional anaerobic chamber in the isolation and identification of clinically significant anaerobes found in human samples, obviating the need for separate anaerobic‐aerobic workstations, expensive anaerobic apparatus, and additional incubator space.

Frequency of isolation of Porphyromonas species from infected dog and cat bite wounds in humans and their characterization by biochemical tests and arbitrarily primed-polymerase chain reaction fingerprinting.

We isolated 40 strains of Porphyromonas (formerly Bacteroides) species from 29 of 102 cat and dog bite wounds in humans. P. salivosa, P. gingivalis, and P. canoris were the most frequent isolates. A comparison of the RapID ANA II system (Innovative Diagnostic Systems, Norcross, GA), An-IDENT panels (bioMérieux, St. Louis), and API ZYM strips (bioMérieux) showed that the latter kit best characterized these isolates because it included tests for trypsin and chymotrypsin activity; however, the tests for glycosidase activity in this kit were less sensitive than were those in the other kits. None of the biochemical systems was able to identify all species. Arbitrarily primed-polymerase chain reaction fingerprinting with a nonspecific single primer, T3B, yielded distinct profiles for type strains and for the clinical isolates, suggesting that some of the isolates represented previously undescribed species. Growth of these species took > or = 5 days; therefore, laboratories should incubate anaerobic plates from bite wound cultures for > or = 7 days to assure isolation of these common pathogens.