Evaluation of the API 20E system for the identification of gram-negative nonfermenters from animal origin.

The API 20E system was evaluated on isolates from animals of aerobic nonfermentative and cytochrome oxidase positive Gram-negative rods. An accuracy of identification of 80% (214/268 isolates) was achieved for those organisms included in the 1976-1977 API profile index. Members of the genera Pseudomonas and Acinetobacter were identified with 100% accuracy. Organisms not included in the API profile gave either an unacceptable profile number or were incorrectly identified as Moraxella spp. When the inoculum size was increased there was better identification.     

Evaluation of different API systems for identification of porcine Pasteurella multocida isolates

An exhaustive biochemical characterisation of 60 porcine Pasteurella multocida clinical isolates recovered from lesions indicative of pneumonia, previously confirmed by PCR and all belonging to the capsular serogroup A, was performed by means of four commercial systems. The API 20NE correctly identified almost all isolates (95%), but only 60% could be ascribed to this species by the API 20E method. The high diversity exhibited by the API 50CHB/E system, with six different patterns, does not advise its use as additional system for a definitive identification at the species level, but this method could be a potential tool for characterising P. multocida isolates below this level. The more uniform reactions yielded by the API ZYM test make this system helpful in the confirmatory identification of this organism. The high variability (20 profiles) obtained when the four systems are taken together also suggests their usefulness for epidemiological purposes in order to sub-type P. multocida isolates.     

Evaluation of API 20E System and Encise Enterotube for the identification of Enterobacteriaceae of animal origin.

The API 20E System and the Encise Enterotube were evaluated for the identification of the Enterobacteriaceae isolated from clinical specimens of animal origin at a veterinary diagnostic laboratory. Compared to conventional tubed media, the API 20E System identified 235 of 240 isolates (97.9%) correctly. The Encise Enterotube correctly identified 229 of the 240 isolates (95.4%). Thus, both these identification systems could be used to replace conventional methods for identifying members of this family isolated from animal origin.     

Comparison of the API 20E and BBL Crystal E/NF Identification Systems for Differentiating Bacterial Isolates from Apparently Healthy Reared Sea Bass (Dicentrarchus labrax)

The ability of two commercial rapid identification systems, API 20E and BBL Crystal E/NF, to reliably identify bacterial isolates from the internal organs of reared sea bass were compared. The tests gave different results: API 20E identified bacteria as Pseudomonas spp. with 37% accuracy, while BBL Crystal E/NF identified them as Flavobacterium odoratum with 99% accuracy. Although F. odoratum is not a marine fish pathogen, conventional tests conducted with the same isolates were more indicative of them being Flavobacterium spp. than Pseudomonas spp., suggesting that BBL Crystal E/NF was more reliable in this identification. Both systems were found to be applicable for diagnostics of marine fish pathogens, but should be used with caution because of possible misinterpretation.     

Comparison of phenotypic and genotypic methods for the species identification of coagulase-negative staphylococcal isolates from bovine intramammary infections

Coagulase-negative staphylococci (CNS) are the most frequently isolated pathogens from cows with intramammary infection (IMI). Although API STAPH ID 20, a commercially available identification system, and PCR-restriction fragment length polymorphism (PCR-RFLP) of the gap gene (gap PCR-RFLP) have been successfully applied for the identification of CNS isolates from human specimens, their accuracy in the identification of veterinary isolates has not been fully established. In this study, we identified 263 CNS isolates from bovine IMI at species level by partial 16S rRNA gene sequence analysis as the definitive test. Species identification obtained using partial 16S rRNA gene sequence analysis was compared to results from the API STAPH ID 20 and gap PCR-RFLP analysis. Eleven different CNS species were identified by partial 16S rRNA gene sequence analysis. Only 76.0% (200/263) of the species identification results obtained by API STAPH ID 20 matched those obtained by partial 16S rRNA gene sequence analysis, whereas 97.0% (255/263) of the species identification results obtained by the gap PCR-RFLP analysis matched those obtained by partial 16S rRNA gene sequence analysis. The gap PCR-RFLP analysis could be a useful and reliable alternative method for the species identification of CNS isolates from bovine IMI and appears to be a more accurate method of species identification than the API STAPH ID 20 system.     

Comparison of Two Biochemical Test Systems with Conventional Methods for the Identification of Bacteria Pathogenic to Warmwater Fish

Abstract

One hundred seven Aeromonas spp., 26 Edwardsiella ictaluri, 6 E. tarda, 12 Plesiomonas shigelloides, and 6 Pseudomonas spp. (131 piscine isolates and 26 reference isolates) were studied with 36 biochemical tests from the Minitek system, 20 tests from the API 20E system, and corresponding standard tube tests. Isolates were incubated at 25°C. Arginine dihydrolase, ornithine decarboxylase, mannose, and citrate showed less than 95% agreement between the Minitek system and the tube tests. Arginine dihydrolase, lysine decarboxylase, nitrite reductase, Voges-Proskauer, and citrate showed less than 95% agreement between the API 20E system and the tube tests. The 26 reference isolates were examined with the three systems and were incubated at both 25 and 37°C. There were no major differences between tests run at 25 and 37°C except with nine Aeromonas spp. that did not grow well at 37°C. Both the Minitek and API 20E systems will reproduce standard biochemical tube test results with at least 95% accuracy when used to test warmwater fish pathogens incubated at 25°C. However, the numerical identification databases for both the Minitek and API 20E systems were not usable for identifying fish pathogens.     

Evaluation of a multi-test microtube system for the identification of veterinary isolates of Enterobacteriaceae

Four hundred and twenty-two isolates of Enterobacteriaceae from veterinary sources were used to evaluate the API20E system. The accuracy of the individual tests, compared to the conventional equivalent was established at a minimum of 88%. The identification level of the system was determined to be 86%, a level considerably lower than that recorded for human clinical and food based studies. If the API20E system is adopted for use in veterinary laboratories, then the limitations of the system must be clearly understood.     

Biotyping of clinical isolates of Escherichia coli of animal origin, using the Analytab API 20E system.

Using the Analytab (API 20E) Enterobacteriaceae system of biochemical identification, a total of 506 Escherichia coli isolates from different animal species were coded numerically or biotyped. Fifty-four different biotypes were identified, 11 accounting for 83.1% of the isolates examined. Three of these profiles accounted for 65.3% of the isolates and were found in almost all animal species. Some of the biotypes were found in only one animal species: six in cattle, five in horses, 15 in pigs, two in sheep, two in birds, one in dogs and one in a porpoise. Biotypes, as determined here, could not be related to a particular pathology and more work is needed to assess the extent and significance of this relative biotype specificity among animal species. The use of other, more sophisticated, typing systems, i.e. plasmid "fingerprinting", or restriction endonuclease analysis of chromosomal DNA, would have to be investigated.     

An evaluation of the API ZYM system as a means of identifying Haemophilus somnus and related taxa.

The commercially available API ZYM microbiological identification system was evaluated for the rapid identification of Haemophilus somnus. Eighty-seven isolates of the organism had API ZYM profiles which were characteristic. The API ZYM profiles demonstrate clear differences between H. somnus and other genera but suggest a close association to three related organisms. Enzyme activity of H. somnus isolates were similar to organisms identified as Histophilus ovis, Haemophilus agni and strains UQV of Actinobacillus actinoides and Actinobacillus seminis but was clearly different from isolates of Pasteurella haemolytica, Pasteurella multocida, Bordetella bronchiseptica and group EF4. The API ZYM system allowed more rapid identification of H. somnus than conventional biochemical tests and may be a useful adjunct to conventional methods used for identification of H. somnus isolates. The test did not reveal obvious differences between isolates from various anatomic locations.     

Efficacy of the API Staph-Ident system for identification of Staphylococcus species from milk

A total of 524 staphylococcal isolates from bovine milk were identified, using the API Staph-Ident system and conventional biochemical methods. The API Staph-Ident system correctly identified 192 of 201 (95.5%) Staphylococcus aureus isolates, but was correct on only 23 of 323 (7.1%) non-S aureus isolates.     

Some features of coagulase positive staphylococci from bovine milk. II. Comparison of conventional techniques and the API Staph system

A total of 150 isolates of Staphylococcus aureus were subjected to the tests on the API Staph system. Of these, 50 were also tested by conventional methods, using the same tests as those found on the API Staph strips. Applying the principles of numerical taxonomy, the relationship between these isolates was 82% and more. Tests for the metabolism of sucrose and N-acetyl-glucosamine and for the production of argenine dihydrolysate and urease appear to be superfluous in the identification of S. aureus in this system.     

The Automicrobic System (AMS)--a new test method for the classification and susceptibility testing of bovine mastitis streptococci

In the period of January 1987 to March 1988 15,800 quarter milk samples from cows of Lower Austrian problem herds were collected and 744 streptococci strains isolated. These 744 isolates were identified by means of the AUTO-MICROBIC-SYSTEM (AMS). As comparative methods the test system API 20 STREP as well as the comparison with the agar-diffusion test. Due to AMS 360 (=48.4%) of the 744 isolates examined could be identified as streptococci and referred to following species: 16 (=4.4%) Sc. agalactiae, 205 (=56.9%) Enterococci; 74 (=20.5%) Sc. uberis; 61 (=16.9%) Sc. of the viridans streptococci and 4 (=1.1%) Sc. pneumoniae. Both test systems AMS and API 20 STREP showed a coincidence of 91.6%.     

The biochemical, morphological and virulence profiles of Bacillus anthracis isolated in the Kruger National Park

The biochemical, morphological and virulence profiles of 44 Bacillus anthracis isolates, obtained from various localities and carcass remains of wild animals in the Kruger National Park, South Africa, were examined. The morphological characteristics tested for included: the formation of capsules on bicarbonate agar, the motility of the vegetative organism, the presence of haemolysis on blood tryptose agar, the sensitivity of the vegetative organism to bacteriophage, the production of lecithinase on egg yolk agar, the liquefaction (hydrolysis) of gelatine and the capability of each isolate to produce mucoid colonies when grown on bicarbonate agar with horse serum in an atmosphere containing CO2. The API 50CHB and 20E systems were used to evaluate the biochemical activity of each isolate. The virulence of each isolate was determined by its LD50, using an inbred line of Balb/C mice. A clear pattern in the biochemical reactions emerged that appeared to be specific for each isolate. On the API 50CHB test strip, only 2 of the 44 isolates gave a 100% positive reaction to all 10 of the biochemical substances to which it was supposed to react, 9 gave positive results to 90%, 19 were positive to 80%, and 14 were positive to 70%. The reactions on the API 20E were completely different from what was expected, with only 1 of the biochemical activities (gelatinase production) showing a positive reaction to all the isolates. The virulence test indicated that 27/44 isolates could be regarded as highly virulent with a LD50 of less than 1,000 organisms, and the rest of the isolates as virulent with a LD 50 of 1,001-10,000 organisms.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rapid identification of Haemophilus somnus, Histophilus ovis and Actinobacillus seminis using the API ZYM system

The API ZYM system, a commercially-available technique that measures bacterial enzyme activity was used to test 43 isolates identified as H. somnus, H. ovis or A. seminis and 19 from related genera. The enzyme patterns resulting from the API ZYM differentiated H. somnus and H. ovis from A. seminis and related genera but not from each other. An identification scheme based on 9 of the enzymes in the API ZYM and a few simple biochemical tests is proposed for the rapid and reliable identification of these bacteria in a diagnostic bacteriology laboratory.     

Fimbriae and enterotoxins associated with Escherichia coli serogroups isolated from pigs with colibacillosis

A comprehensive study of 223 Escherichia coli isolates from pigs with colibacillosis included determination of O serogroups, detection of heat-labile enterotoxin, heat-stable enterotoxin (STa and STb), and identification of K88, K99, 987-P, F-41, and type 1 fimbriae. The incidence of the various E coli types among isolates of pigs of different ages was also determined. Escherichia coli bearing K88 fimbriae accounted for 48% of all isolates studied, were most often of serogroup O157, O149, or O8, and usually produced labile toxin alone or in combination with STa or STb. These E coli were commonly isolated from pigs in each age group studied (0 to 5 days, 6 to 10 days, 11 to 24 days, and greater than 24 days). Escherichia coli bearing 987-P accounted for 30% of the isolates, were most often of serogroup O141 or O20, and usually produced STa. Escherichia coli bearing K99 accounted for 13% of the isolates, usually were of serogroup O101 or O8, and almost always produced STa. Escherichia coli bearing 987-P or K99 were most often isolated from pigs less than 6 days of age. Fimbriae F-41, when identified, were usually on E coli of serotype O101:K99. Although infrequently found, type 1 fimbriae were on E coli of most of the serogroups identified in this study.     

Identification of Yersinia enterocolitica in minced meat: a comparative analysis of API 20E, Yersinia identification kit and a 16S rRNA-based PCR method

The isolation and identification of Yersinia enterocolitica from minced meat on CIN agar medium is still one of the major problems in food microbiology because of the low selectivity of cefsulodin-irgasan-novobiocin (CIN) agar. A total of 198 minced meat samples were collected from commercial establishments (butcher shops and supermarkets) in seven German cities in order to investigate the sensitivity and specificity of three identification techniques suitable for the differentiation of Y. enterocolitica within the rich background flora on CIN agar plates. As expected isolation of Y. enterocolitica from minced meat on CIN agar medium after 72 h enrichment in peptone, sorbitol and bile salts (PSB) broth was difficult because all plates were abundantly covered with numerous 'typical'Yersinia-like colonies of bull's eye appearance as well as with atypical colonies. Based on the phenotype of the colonies it was possible to detect colonies showing Yersinia-like growth on CIN agar in 52 samples (26%). For identification of Y. enterocolitica the API 20E system (bioMerieux, Nürtingen, Germany), the Yersinia identification kit (Merlin, Bornheim-Hersel, Germany) and a 16S rRNA based PCR assay were compared. Only in one sample (0.5%) a Y. enterocolitica strain was detected by all methods. Of the three identification systems tested for routine laboratory diagnostics the API 20E system was found to be the most suitable tool to identify Y. enterocolitica colonies within the rich background flora from minced meat samples on CIN agar plates.     

动物性食品源大肠杆菌O血清型鉴定及其K88菌毛基因检测

本研究对河北省冀东地区农贸市场和超市采集的生猪肉、生鸡蛋和生羊肉等分离得到的20株大肠杆菌进行大肠杆菌血清型鉴定;并检测不同血清型大肠杆菌的K88菌毛基因。采用常规方法进行大肠杆菌的O血清型鉴定,用PCR方法检测K88菌毛基因。分离鉴定的20株大肠杆菌有7种血清型,包括O38、O78、O88、O11、O107、O91、O9,其中O38、O78为优势血清型菌,均占分离菌株的25%(5/20)。在分离的动物性食品源大肠杆菌中有30%(6/20)的菌株K88菌毛基因扩增呈阳性。结果表明,O78、O38为冀东地区动物性食品源大肠杆菌常见血清型,30%(6/20)的菌株K88菌毛基因扩增阳性。     

Sero-prevalence and identification of <Emphasis Type="Italic">Ornithobacterium rhinotracheale</Emphasis> in broiler flocks in south-eastern Iran

Ornithobacterium rhinotracheale is a gram negative bacterial pathogen causing respiratory tract infections in poultry. Tracheal, lung and serum samples were obtained from 21 broiler flocks of 8 farms from a slaughterhouse located in south-eastern of Iran. Among 630 tracheal and lung samples from samples resulting from 315 chickens, 11 (3.5%) ORT isolates were identified using biochemical tests. The isolates originated from 9 (42.9%) flocks out of 4 farms. All of the isolates were recovered from tracheal swabs and showed an API 20NE identification biocode 0-2-2-0-0-0-4. Of the 420 serum samples examined by ELISA, 134 (31.9%) sera from 17 (81.0%) flocks were positive for ORT antibodies. These results indicate that ORT is present in most broiler flocks with respiratory disorders in southeast Iran.     

Isolation and characterisation of Bordetella avium and related species and an evaluation of their role in respiratory disease in poultry

A total of 24 Gram negative non fermentative bacteria obtained from poultry were compared with reference strains of Bordetella avium, Alcaligenes faecalis, Bordetella bronchiseptica and a Bordetella avium-like organism. Thirteen isolates were identified as B. avium and 11 were identified as B. avium-like. A commercial microidentification kit (the API2ONE) did not identify the field isolates but did separate them correctly into the 2 groups. A practical identification scheme, suitable for diagnostic laboratories, is proposed for these organisms. The available clinical histories suggest that B. avium is associated with upper respiratory tract disease in turkeys.     

The usefulness of the API 20 E classification system in the identification of Actinobacillus actinomycetem comitans, Actinobacillus seminis and Pasteurella haemolytica

The prepuces of lambs aged 6--8 months and semen of 2 adult rams were found to be infected with gram negative, non-motile, non-haemolytic, pleomorphic bacilli. These organisms were compared with those of known strains of actinobacillus actinomycetem comitans. Actinobacillus seminis and Pasteurella haemolytica, using the API 20 E classification system. Applying the principles of numerical taxonomy, the majority of suspected strains of A. seminis could be classified as A. actinomycetem comitans and 3 examples as Histophilus ovis. Although some of the suspected strains of A. seminis could be classified as P. haemolytica, obvious differences between the genera Actinobacillus and Pasteurella were evident.