Detection of Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus and Listeria monocytogenes in kimchi by multiplex polymerase chain reaction (mPCR)

We developed an mPCR assay for the simultaneous detection, in one tube, of Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus and Listeria monocytogenes using species-specific primers. The mPCR employed the E. coli O157:H7 specific primer Stx2A, Salmonella spp. specific primer Its, S. aureus specific primer Cap8A-B and L. monocytogenes specific primer Hly. Amplification with these primers produced products of 553, 312, 405 and 210 bp, respectively. All PCR products were easily detected by agarose gel electrophoresis, and the sequences of the specific amplicons assessed. Potential pathogenic bacteria, in laboratory-prepared and four commercially available kimchi products, were using this mPCR assay, and the amplicons cloned and sequenced. The results correlated exactly with sequences derived for amplicons obtained during preliminry tests with known organisms. The sensitivity of the assay was determined for the purified pathogen DNAs from four strains. The mPCR detected pathogen DNA at concentrations ranging from approximately 0.45 to 0.05 pM/microl. Thus, this mPCR assay may allow for the rapid, reliable and cost-effective identification of four potentially pathogens present in the mixed bacterial communities of commercially available kimchi.     

Multiplex PCR assay for detection of four major bacterial pathogens causing rainbow trout disease

A multiplex PCR (mPCR) method was designed for the simultaneous detection of 4 major fish pathogens, Flavobacterium psychrophilum, Lactococcus garvieae, Pseudomonas aeruginosa, and P. putida. Each of the 4 pairs of oligonucleotide primers exclusively amplified the 16S rDNA gene of their targeted microorganism. The average detection limits for each organism amplified by mPCR were 2 colony-forming units (CFU) of F. psychrophilum, 3 CFU of L. garvieae, 3 CFU of P. aeruginosa, and 5 CFU of P. putida in mixed cultures. Multiplex PCR did not produce any nonspecific amplification products when tested against 28 related species of bacteria. High amounts of DNA from 1 bacterial species had a significant effect on the amplification sensitivity of the other bacterial species when these were present in lower concentrations in the multiplex reaction. The mPCR assay proved useful for the detection of the bacteria in naturally infected fish. The assay is a sensitive, specific, and reproducible diagnostic tool for the simultaneous detection of 4 pathogenic bacteria that cause disease in fish and offers a potentially useful alternative to the conventional culture-based method.     

Multiplex polymerase chain reaction to identify and determine the toxigenicity of Corynebacterium spp with zoonotic potential and an overview of human and animal infections

Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis constitute a group of potentially toxigenic microorganisms that are related to different infectious processes in animal and human hosts. Currently, there is a lack of information on the prevalence of disease caused by these pathogens, which is partially due to a reduction in the frequency of routine laboratory testing. In this study, a multiplex polymerase chain reaction (mPCR) assay that can simultaneously identify and determine the toxigenicity of these corynebacterial species with zoonotic potential was developed. This assay uses five primer pairs targeting the following genes: rpoB (Corynebacterium spp), 16S rRNA (C. ulcerans and C. pseudotuberculosis), pld (C. pseudotuberculosis), dtxR (C. diphtheriae) and tox [diphtheria toxin (DT) ]. In addition to describing this assay, we review the literature regarding the diseases caused by these pathogens. Of the 213 coryneform strains tested, the mPCR results for all toxigenic and non-toxigenic strains of C . diphtheriae, C. ulcerans and C. pseudotuberculosis were in 100% agreement with the results of standard biochemical tests and PCR-DT. As an alternative to conventional methods, due to its advantages of specificity and speed, the mPCR assay used in this study may successfully be applied for the diagnosis of human and/or animal diseases caused by potentially toxigenic corynebacterial species.     

Fabrication and optimization of the multiplex PCR-based oligonucleotide microarray for detection of Neisseria gonorrhoeae, Chlamydia trachomatis and Ureaplasma urealyticum

To detect and identify the pathogens responsible for sexually transmitted diseases (STDs) at the early stage of infection and with a high throughput, a new microarray with a bifunctional probe modification was prepared using Neisseria gonorrhoeae, Chlamydia trachomatis and Ureaplasma urealyticum as a model system. During the fabrication of the microarray, an asymmetric fluorescently labeled multiplex PCR was introduced. The fabrication optimization proved that the best hybridization results would be obtained by spotting N. gonorrhoeae probe at a position near the side of the fluorescently labeled reverse primer within its target gene and spotting each probe at a concentration of 50 microM onto the aldehyde-derived glass slides using spotting solution S1 and using hybridization solution H2 for hybridization. The probes designed by our laboratory could specifically discriminate the pathogens of N. gonorrhoeae, C. trachomatis and U. urealyticum in the presence of the internal control on the microarray simultaneously and separately. By incorporating the key features of DNA microarray with those of multiplex PCR, the microarray provides a fast high throughput platform for multiple infections and multiple samples to be detected and identified simultaneously for STD clinics. It also provides a new platform for other diseases and gene mutations to be detected and identified at a high throughput.     

检测PCV2、PPV、PRV疫苗株与野毒株的多重PCR方法

本文建立了一种同时检测猪圆环病毒2型（PCV2）、细小病毒（PPV）、及伪狂犬病毒（PRV）疫苗株与野毒株的多重PCR方法.根据GenBank上发表的PCV2、PPV和PRV gB、gE基因序列,针对各自保守区各设计一对特异性引物,用这四对引物对同一样品中的PCV2、PPV和PRV gB、gE进行检测,结果可同时扩增出269bp（PCV2）、581bp（PPV）、372bP（PRV gB）及147bp（PRV gE）四条特异性片段.对JEV、PRRSRV、大肠杆菌和双蒸水的PCR扩增结果均为阴性;敏感性测定结果表明,该多重PCR能检出10pg PCV2、PPV和PRV gB、gE检测敏感度分别为10^-6.2、10^-3.8、10^-5.8TCID50的模板.该方法的建立对临床上进行这三种疾病的鉴别诊断和混合感染的检测具有重要意义.     

转基因白桦外源基因的多重PCR快速检测

根据转化的载体序列上T-DNA中的目的基因bt,选择性筛选标记基因nptⅡ和报告基因gus设计三对特异性引物,PCR产物片断大小分别为247、449、668 bp,应用多重PCR (mutiplex-PCR)的方法同步检测18株转基因白桦中三个基因的整合状况;用阳性对照为模板,对单重PCR（simplex-PCR）和多重PCR的各项指标进行比较。结果表明多重PCR检测多个外源基因在敏感性方面与单重PCR相比并没有减弱,而且略有提高;对18株样品的多重PCR同步检测无假阳性出现,结果准确,同时在操作中具有减少污染,缩短时间和节约成本等优点。因此,在对转基因白桦的外源基因的定期检测中,多重PCR是一种非常有效而便捷的方法,可以为转基因的拷贝数,T-DNA旁侧序列特征等转基因整合特性方面的研究提供数据。     

基因芯片技术检测3种食源性致病微生物方法的建立

建立一种运用多重PCR和基因芯片技术检测和鉴定志贺氏菌、沙门氏菌、大肠杆菌O157的方法, 为3种食源性致病菌的快速检测和鉴定提供了准确、快速、灵敏的方法。分别选取编码志贺氏菌侵袭性质粒抗原H基因(ipaH)、沙门氏菌肠毒素(stn)基因和致泻性大肠杆菌O157志贺样毒素(slt)基因设计引物和探针, 进行三重PCR扩增, 产物与含特异性探针的芯片杂交。对7种细菌共26株菌进行芯片检测, 仅3种菌得到阳性扩增结果, 证明此方法具有很高的特异性。3种致病菌基因组DNA和细菌纯培养物的检测灵敏度约为8 pg。对模拟食品样品进行直接检测, 结果与常规细菌学培养结果一致, 检测限为50 CFU/mL。结果表明：所建立的基因芯片检测方法特异性好, 灵敏度高, 为食源性致病菌的检测提供了理想手段, 有良好的应用前景。     

Detection of toxigenic strains of <Emphasis Type="Italic">Aeromonas</Emphasis> species in foods by a multiplex PCR assay

Aeromonas hydrophila and other aeromonads are ubiquitous organisms found in meat, vegetables, drinking water and various other food items. They cause diarrhea and extra-intestinal infections in normal and immunocompromised patients. The aim of the study was to develop a multiplex PCR assay for the detection of virulence-associated genes of Aeromonas including hemolysin (hlyA), aerolysin (aerA), glycerophospholipid-cholesterol acyl transferase (GCAT) alongwith a 16S rRNA gene. Internal amplification control (IAC), which was coamplified with aerA primers, was also included in this study. The results showed that all cultures of Aeromonas were accurately identified by the assay without showing non-specificity. A. hydrophila could be detected at a range of 10–50 CFU ml⁻¹ from experimentally spiked fish, chicken and milk samples following overnight enrichment in alkaline peptone water supplemented with 10 μg/ml ampicillin (APW-A) by this multiplex PCR (mPCR). When evaluated on a total of 74 naturally occurring food samples, four samples were identified to contain Aeromonas by mPCR. All these results were compared to the conventional culture, isolation and biochemical identification procedures. The high throughput and cost-effective mPCR method developed in this study could provide a powerful tool for detection of pathogenic Aeromonas spp. from food and environmental samples and in addition, the method has advantages in terms of specificity, sensitivity and ease of use compared to other reported PCR methods and DNA hybridization assays.     

Rapid and sensitive detection of major uropathogens in a single-pot multiplex PCR assay

Urinary tract infection (UTI) is among the most common bacterial infections and poses a significant healthcare burden. Escherichia coli is the most common cause of UTI accounting for up to 70?% and a variable contribution from Proteus mirabilis, Pseudomonas aeruginosa and Klebsiella pneumoniae. To establish a complete diagnostic system, we have developed a single-tube multiplex PCR assay (mPCR) for the detection of the above-mentioned four major uropathogens. The sensitivity of the assay was found to be as low as 10(2)?cfu/ml of cells. The mPCR evaluated on 280 clinical isolates detected 100?% of E. coli, P. aeruginosa, P. mirabilis and 95?% of K. pneumonia. The assay was performed on 50 urine samples and found to be specific and sensitive for clinical diagnosis. In addition, the mPCR was also validated on spiked urine samples using 40 clinical isolates to demonstrate its application under different strain used in this assay. In total, mPCR reported here is a rapid and simple screening tool that can compete with conventional biochemical-based screening assays that may require 2-3?days for detection.     

Simultaneous detection and differentiation of pathogenic and nonpathogenic Leptospira spp. by multiplex real-time PCR (TaqMan) assay

Leptospirosis, caused by pathogenic Leptospira, is one of the most important zoonoses in the world. Several molecular techniques have been developed for detection and differentiation between pathogenic and saprophytic Leptospira spp. The aim of this study was to develop a rapid and simple assay for specific detection and differentiation of pathogenic Leptospira spp. by multiplex real-time PCR (TaqMan) assay using primers and probes targeting Leptospira genus specific 16S ribosomal RNA gene, the pathogen specific lig A/B genes and nonpathogen Leptospira biflexa specific 23S ribosomal RNA gene. Sixteen reference strains of Leptospira spp. including pathogenic and nonpathogenic and ten other negative control bacterial strains were used in the study. While the 16S primers amplified target from both pathogenic and non-pathogenic leptospires, the ligA/B and the 23S primers amplified target DNA from pathogenic and non-pathogenic leptospires, respectively. The multiplex real-time PCR (TaqMan) assay detection limit, that is, the sensitivity was found approximately 1 x 10(2) cells/ml for ligA/B gene and 23S ribosomal RNA gene, and 10 cells/ml 16S ribosomal RNA. The reaction efficiencies were 83-105% with decision coefficients of more than 0.99 in all multiplex assays. The multiplex real-time PCR (TaqMan) assay yielded negative results with the ten other control bacteria. In conclusion, the developed multiplex real-time PCR (TaqMan) assay is highly useful for early diagnosis and differentiation between pathogenic and non-pathogenic leptospires in a reaction tube as having high sensitivity and specificity.     

Detection of Pseudomonas aeruginosa from clinical and environmental samples by amplification of the exotoxin A gene using PCR.

PCR was used to detect Pseudomonas aeruginosa from water samples by amplifying a 396-bp region of the exotoxin A (ETA) structural gene sequence. The identify of the amplified 396-bp fragment was confirmed by digesting it with PvuI restriction endonuclease, which produced the predicted 246- and 150-bp fragments. Specific primers amplified ETA-positive P. aeruginosa DNA, whereas other species of Pseudomonas and GC-rich bacteria did not yield any 396-bp fragment. The specificity and sensitivity of the assay were 100 and 96%, respectively, which confirms the assay's reliability for diagnostic and epidemiological studies. The assay can detect as few as 5 to 10 cells in a 10-ml water sample or 0.1 pg of P. aeruginosa DNA per reaction mixture (5 microliters) by ethidium bromide staining of an agarose gel. Ten-times-lower concentrations were detected by hybridization with a digoxigenin-labeled oligonucleotide probe internal to the PCR product. With this PCR method, ETA-positive P. aeruginosa was detected in animal cage water samples at a level of 40 cells per ml. This method is rapid and less cumbersome than other diagnostic methods for the identification of P. aeruginosa strains. The method described can be used to detect a low level of P. aeruginosa from environmental and clinical samples without the use of selective media or additional biochemical tests.     

Evaluation of broiler litter with reference to the microbial composition as assessed by using 16S rRNA and functional gene markers

Very little is known about the microbial composition of animal bedding wastes, including poultry litter, and what is known has been deduced from standard culture methods, by which some fastidious organisms that exist in the environment may not be detected. We evaluated the bacterial composition of poultry litter by using a combination of culture and molecular detection. Total aerobic bacteria in poultry litter were detected by culture at 10(9) CFU/g of material. Enteric bacteria such as Enterococcus spp. and coliforms composed 0.1 and 0.01%, respectively, of the total aerobic cultivatable bacteria in poultry litter; no Salmonella strains were detected by culture. In order to characterize the most abundant bacterial groups, we sequenced 16S ribosomal DNA (rDNA) genes amplified by PCR with microbial community DNA isolated from poultry litter as the template. From the 16S rDNA library, 31 genera were identified. Twelve families or groups were identified with lactobacilli and Salinococcus spp. forming the most abundant groups. In fact, 82% of the total sequences were identified as gram-positive bacteria with 62% of total belonging to low G+C gram-positive groups. In addition to detection of 16S rDNA sequences associated with the expected fecal bacteria present in manure, we detected many bacterial sequences for organisms, such as Globicatella sulfidofaciens, Corynebacterium ammoniagenes, Corynebacterium urealyticum, Clostridium aminovalericum, Arthrobacter sp., and Denitrobacter permanens, that may be involved in the degradation of wood and cycling of nitrogen and sulfur. Several sequences were identified in the library for bacteria associated with disease in humans and poultry such as clostridia, staphylococci, and Bordetella spp. However, specific PCR targeting other human and veterinary pathogens did not detect the presence of Salmonella, pathogenic Escherichia coli, Campylobacter spp., Yersinia spp., Listeria spp., or toxigenic staphylococci. PCR and DNA hybridization revealed the presence of class 1 integrons with gene cassettes that specify resistance to aminoglycosides and chloramphenicol. Only from understanding the microbial community of animal wastes such as poultry litter can we manage animal disease and limit the impact of animal waste on the environment and human and animal health.     

Detection of Salmonella enterica serovar Typhi (S. Typhi) by selective amplification of invA, viaB, fliC-d and prt genes by polymerase chain reaction in mutiplex format

AIMS: Development of a PCR assay that can target multiple genes for rapid detection of Salmonella enterica serovar Typhi (S. Typhi) from water and food samples. METHODS AND RESULTS: PCR primers for invasion, O, H and Vi antigen genes, invA, prt, fliC-d and viaB were designed and used for the rapid detection of S. Typhi by multiplex PCR. Internal amplification control, which co-amplified with prt primers, was also included in the assay. The results showed that all cultures of Salmonella were accurately identified by the assay with no nonspecific amplification in other cultures. The assay had 100% detection probability when a cell suspension of 10(4) CFU ml(-1) (500 CFU per reaction) was used. Salmonella Typhi bacteria were artificially inoculated in the water and food (milk and meat rinse) samples and detected by mPCR after overnight pre-enrichment in buffered peptone water. No Salmonella bacteria could be detected from water samples collected from the field by mPCR or standard culture method. CONCLUSIONS: The developed mPCR assay provides specific detection of S. Typhi. SIGNIFICANCE AND IMPACT OF THE STUDY: Rapid methods for detection of S. Typhi from complex environmental matrices are almost nonexistent. The mPCR assay reported in this study can be useful to identify S. Typhi bacteria in field environmental samples.     

性传播疾病性尿道炎后慢性前列腺炎病原学分析

目的：了解性传播疾病(sexually transmitted disease,STD)性尿道炎后慢性前列腺炎患者前列腺液(expressed prostatic secretion,EPS)标本中病原体的感染状况及对常用抗菌药物的敏感性。方法：对性传播疾病后慢性前列腺患者的EPS进行病原体检测和药敏试验。结果：126例患者中96例分离出病原体115株,阳性率为76．2％。主要病原体为金黄色葡萄球菌(20．0％)、解脲支原体(18．3％)、表皮葡萄球菌(14．8％)和淋球菌(13．9％),混合感染率达15．1％。药敏试验显示解脲支原体对四环素、红霉素和氧氟沙星耐药,而对原始霉素、强力霉素和交沙霉素敏感。葡萄球菌属对万古霉素、呋喃妥因和头孢唑啉最为敏感。结论,提示EPS的病原体检测对临床诊断和治疗性传播疾病后慢性前列腺炎具有重要意义。     

Development of a combined PCR-culture technique for the rapid detection of Arcobacter spp. in chicken meat

A combined PCR-culture technique was developed to detect Arcobacter spp. in fresh chicken meat. Following a short selective enrichment of chicken samples, bacterial DNA was extracted and amplified using primers targeted at the genes encoding 16S rRNA of Arcobacter spp. The selected primers amplify a 181-bp fragment from all Arcobacter spp., whereas no PCR product is generated for other bacteria, including the closely related Campylobacter and Helicobacter species. The assay was used to screen 96 retail-purchased chicken samples for the presence of Arcobacter spp. Fifty-three percent of the samples analysed were positive for this micro-organism. The assay is simple and sensitive and reduces the amount of time required to positively detect Arcobacter spp. in poultry meat.     

PCR assay for discriminating between infectious hypodermal and hematopoietic necrosis virus (IHHNV) and virus-related sequences in the genome of Penaeus monodon

We developed a PCR assay that can detect infectious hypodermal and hematopoietic necrosis virus (IHHNV) but that does not react with IHHNV-related sequences in the genome of Penaeus monodon from Africa and Australia. IHHNV is a single-stranded DNA virus that has caused severe mortality and stunted growth in penaeid shrimp. Recently, IHHNV-related sequences were found in the genome of some stocks of P. monodon from Africa and Australia. These virus-related sequences have a high degree of similarity (86 and 92% identities in nucleotide sequence) to the viral genome, which has often generated false-positive reactions during PCR screening of these stocks. For this assay, a pair of IHHNV primers (IHHNV309F/R) was selected. The sequences of these primers match (100% of nucleotides) the target sequence in IHHNV, but mismatch 9 or 12 nucleotides of the genomic IHHNV-related sequences. This PCR assay was tested with various IHHNV isolates and with a number of samples of shrimp DNA that contained IHHNV-related sequences. This assay can reliably distinguish IHHNV DNA from shrimp DNA: it only detects IHHNV. Also, this pair of primers was included in a duplex PCR to detect IHHNV and simultaneously determine the presence of an IHHNV-related sequence. Using these primers, the PCR assay has a sensitivity equivalent to a PCR assay commonly used for detecting IHHNV in Litopenaeus vannamei, and can be used for routine detection.     

Detection of Fusarium wilt pathogens of Psidium guajava L. in soil using culture independent PCR (ciPCR)

Traditional culturing methods take a long time for identification of pathogenic isolates. A protocol has been developed for the detection of Fusarium from soil samples in the early stage of infection. Seventeen soil samples from different locations were collected before the onset of rains to find out the presence of Fusarium spp. population present in the soil of guava orchards and to correlate its presence with incidence of wilt. A PCR based method was developed for the molecular characterization of Fusarium using Fusarium spp. specific primer. DNA extracted by this method was free from protein and other contaminations and the yield was sufficient for PCR amplification. The primer developed in this study was amplifying ∼230 bp in all infected samples while not in healthy soil. The specificity and sensitivity of primer were tested on several Fusarium spp. and found that this primer was amplifying 10⁻⁶ dilution of the fungal DNA. The present study facilitates the rapid detection of Fusarium spp. from infected soil samples of guava collected from different agroclimatic regions in India. A rapid detection method for pathogens and a diagnostic assay for disease would facilitate an early detection of pathogen and lead to more effective control strategies.     

Multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB)--a practical epidemiological and diagnostic tool

Combining multiplex PCR, sequentially, with reverse line blot hybridization (mPCR/RLB) is a convenient, objective way to identify up to 43 targets in 43 individual specimens simultaneously (using a 45-lane membrane format). It is more flexible and less expensive than DNA microarray. The number of targets is adequate for epidemiological and most clinical diagnostic applications; based on the same target (43) and specimen numbers (43), it is much more practical than conventional uniplex PCR (uPCR) and mPCR. We have used the protocol to identify and subtype bacteria, viruses and fungi and identify pathogens in clinical specimens; potentially, it could be used for many other applications, such as detection of mutations in, or identification of alleles of, eukaryotic genes. Development of each assay involves (i) careful primer and probe design, based on literature and sequence database searches, which are critical to success of the assay; and (ii) bench-top evaluation, using known samples, controls and dilution series, to confirm sensitivity, specificity and reproducibility. The assay takes about one and half working days to complete; about 4 h for the mPCR and 6 h for the RLB, including a total of 4 h 'hands-on' time.     

Normal conjunctival flora in the North American opossum (Didelphis virginiana) and raccoon (Procyon lotor)

We documented the normal conjunctival bacterial flora from 17 opossums (Didelphis virginiana) and 10 raccoons (Procyon lotor) trapped in Manhattan, Kansas (USA) from November 1999 to January 2000. Both raccoons and opossums were free of apparent ocular disease. The inferior conjunctival sacs of each animal were swabbed for aerobic bacterial and Mycoplasma culture and polymerase chain reaction (PCR) for Mycoplasma and Chlamydia detection. All conjunctival samples were positive for one or more species of aerobic bacteria. The most common isolate from opossums was Staphylococcus spp. Other isolates included Streptococcus spp., Bacillus spp., Corynebacterium spp., and Enterococcus faecalis. The most common isolates in raccoons was Bacillus spp. Other isolates included Streptococcus spp., Staphylococcus spp., non-hemolytic Escherichia coli, and Enterococcus faecalis. Mycoplasma culture was negative in samples from opossums and raccoons. Evidence of Mycoplasma and Chlamydia presence was detected by PCR.     

PCR法快速鉴定眼源性蜡样芽胞杆菌

目的建立一种快速、灵敏、特异的眼源性蜡样芽胞杆菌PCR检测方法,为蜡样芽胞杆菌性眼内炎患者的快速诊断提供依据。方法选择编码蜡样芽胞杆菌细胞毒素的cytK为靶基因设计引物,建立检测眼源性蜡样芽胞杆菌PCR;PCR产物用琼脂糖凝胶电泳鉴定,基因序列与GenBank比对验证扩增产物;将计数过的5株蜡样芽胞杆菌菌悬液,梯度稀释后分别提取DNA进行PCR扩增,确定检测方法的灵敏度;分别用眼部常见感染菌金黄色葡萄球菌、表皮葡萄球菌、甲型溶血性链球菌、化脓性链球菌、藤黄微球菌、铜绿假单胞菌、大肠埃希菌、普通变形杆菌和白假丝酵母菌以及枯草芽胞杆菌DNA进行特异性试验;进一步将该方法应用到人工污染致病蜡样芽胞杆菌的房水标本中,并分析其灵敏度。结果5株分离自眼内炎患者标本中的蜡样芽胞杆菌均扩增出360bp左右的DNA片段,测序结果与GenBank比对一致;该法检测在5h内完成,方法灵敏度达7．5～15．0CFU／mL;其他菌株检测未出现非特异性扩增;对模拟感染房水标本的PCR鉴定结果与分离培养对比,二者符合率为100％,模拟标本的检测灵敏度与纯菌结果一致。结论cytK基因为靶基因的PCR用于眼源性蜡样芽胞杆菌的快速检测,具有简便、快速、敏感、特异等特点,为眼内炎患者的快速诊断提供依据,在实际检验工作中有良好的应用前景。