scholarly journals Diagnostic Findings in a Confirmed Outbreak of Brucella ovis Infection in a Traditional Sheep Farm in Sicily (South-Italy)

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1472
Author(s):  
Paola Galluzzo ◽  
Sergio Migliore ◽  
Silvana Cascio ◽  
Santino Barreca ◽  
Marilena Alfano ◽  
...  

Aim of this study is to report a laboratory investigation performed following the isolation of Brucella ovis, causing ovine epididymitis, in a traditional sheep farm in Sicily (South Italy). This disease represents a newly emerging risk for Italian livestock and is listed among diseases of EU priority (EU Reg 2016/429). Blood samples from 56 rams and 143 ewes were analyzed by both Enzyme-Linked Immunosorbent Assay (ELISA) and Complement Fixation Test (CFT). Genital swabs from all rams and 15 lactating ewes were collected to perform real-time PCR. Eighteen serologically positive rams were slaughtered and postmortem-inspected. Samples of testicle, epididymis, lymph nodes, and urine were also collected in order to perform microbiological, molecular, and histopathological analysis. Twelve slaughtered rams showed anatomo-pathological lesions. Real-time PCR for B. ovis BOV_A0504 gene was positive for 13 testicles and epididymis and 11 urine while B. ovis was isolated from epididymis and testicles of 7 slaughtered rams. This is the first exhaustive laboratory report of a microbiological, molecular, and serological pattern of the disease in sheep in Italy. Despite the impact on health and animal welfare, the epidemiology of B. ovis infection is still unknown, particularly in our country where the disease is considered endemic.

2003 ◽  
Vol 69 (6) ◽  
pp. 3350-3358 ◽  
Author(s):  
Brett R. Baldwin ◽  
Cindy H. Nakatsu ◽  
Loring Nies

ABSTRACT Our abilities to detect and enumerate pollutant-biodegrading microorganisms in the environment are rapidly advancing with the development of molecular genetic techniques. Techniques based on multiplex and real-time PCR amplification of aromatic oxygenase genes were developed to detect and quantify aromatic catabolic pathways, respectively. PCR primer sets were identified for the large subunits of aromatic oxygenases from alignments of known gene sequences and tested with genetically well-characterized strains. In all, primer sets which allowed amplification of naphthalene dioxygenase, biphenyl dioxygenase, toluene dioxygenase, xylene monooxygenase, phenol monooxygenase, and ring-hydroxylating toluene monooxygenase genes were identified. For each primer set, the length of the observed amplification product matched the length predicted from published sequences, and specificity was confirmed by hybridization. Primer sets were grouped according to the annealing temperature for multiplex PCR permitting simultaneous detection of various genotypes responsible for aromatic hydrocarbon biodegradation. Real-time PCR using SYBR green I was employed with the individual primer sets to determine the gene copy number. Optimum polymerization temperatures for real-time PCR were determined on the basis of the observed melting temperatures of the desired products. When a polymerization temperature of 4 to 5�C below the melting temperature was used, background fluorescence signals were greatly reduced, allowing detection limits of 2 � 102 copies per reaction mixture. Improved in situ microbial characterization will provide more accurate assessment of pollutant biodegradation, enhance studies of the ecology of contaminated sites, and facilitate assessment of the impact of remediation technologies on indigenous microbial populations.


2003 ◽  
Vol 69 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Merete Lunde ◽  
Janet Martha Blatny ◽  
Dag Lillehaug ◽  
Are Halvor Aastveit ◽  
Ingolf F. Nes

ABSTRACT Bacteriophages are a common and constant threat to proper milk fermentation. It has become evident that lysogeny is widespread in lactic acid bacteria, and in this work the temperate lactococcal bacteriophage φLC3 was used as a model to study prophage stability in lactococci. The stability was analyzed in six φLC3 lysogenic Lactococcus lactis subsp. cremoris host strains when they were growing at 15 and 30°C. In order to perform these analyses, a real-time PCR assay was developed. The stability of the φLC3 prophage was found to vary with the growth phase of its host L. lactis IMN-C1814, in which the induction rate increased during the exponential growth phase and reached a maximum level when the strain was entering the stationary phase. The maximum spontaneous induction frequency of the φLC3 prophage varied between 0.32 and 9.1% (28-fold) in the six lysogenic strains. No correlation was observed between growth rates of the host cells and the spontaneous prophage induction frequencies. Furthermore, the level of extrachromosomal phage DNA after induction of the prophage varied between the strains (1.9 to 390%), and the estimated burst sizes varied up to eightfold. These results show that the host cells have a significant impact on the lytic and lysogenic life styles of temperate bacteriophages. The present study shows the power of the real-time PCR technique in the analysis of temperate phage biology and will be useful in work to reveal the impact of temperate phages and lysogenic bacteria in various ecological fields.


2014 ◽  
Vol 35 (6) ◽  
pp. 667-673 ◽  
Author(s):  
Hoonmo L. Koo ◽  
John N. Van ◽  
Meina Zhao ◽  
Xunyan Ye ◽  
Paula A. Revell ◽  
...  

Objective.To evaluate the accuracy of real-time polymerase chain reaction (PCR) for Clostridium difficile–associated disease (CDAD) detection, after hospital CDAD rates significantly increased following real-time PCR initiation for CDAD diagnosis.Design.Hospital-wide surveillance study following examination of CDAD incidence density rates by interrupted time series design.Setting.Large university-based hospital.Participants.Hospitalized adult patients.Methods.CDAD rates were compared before and after real-time PCR implementation in a university hospital and in the absence of physician and infection control practice changes. After real-time PCR introduction, all hospitalized adult patients were screened for C. difficile by testing a fecal specimen by real-time PCR, toxin enzyme-linked immunosorbent assay, and toxigenic culture.Results.CDAD hospital rates significantly increased after changing from cell culture cytotoxicity assay to a real-time PCR assay. One hundred ninety-nine hospitalized subjects were enrolled, and 101 fecal specimens were collected. C. difficile was detected in 18 subjects (18%), including 5 subjects (28%) with either definite or probable CDAD and 13 patients (72%) with asymptomatic C. difficile colonization.Conclusions.The majority of healthcare-associated diarrhea is not attributable to CDAD, and the prevalence of asymptomatic C. difficile colonization exceeds CDAD rates in healthcare facilities. PCR detection of asymptomatic C. difficile colonization among patients with non-CDAD diarrhea may be contributing to rising CDAD rates and a significant number of CDAD false positives. PCR may be useful for CDAD screening, but further study is needed to guide interpretation of PCR detection of C. difficile and the value of confirmatory tests. A gold standard CDAD diagnostic assay is needed.Infect Control Hosp Epidemiol 2014;35(6):667–673


2015 ◽  
Vol 154 (1) ◽  
pp. 109-117 ◽  
Author(s):  
H. M. N. CHEEMA ◽  
A. A. KHAN ◽  
M. I. KHAN ◽  
U. ASLAM ◽  
I. A. RANA ◽  
...  

SUMMARYGenetically modified (GM) plants expressing Bt toxin provide protection against lepidopteran pests. The only GM crop in Pakistan is Bt cotton, which was illegally imported and adopted rapidly by cotton producers. Farmers gained access to the seed of many unapproved Bt genotypes before the matter was picked up and formal approval granted by the relevant governmental agencies. The present study was conducted to evaluate the samples of Bt cotton, collected from farmers and seed dealer, for transgene integration and expression. Seeds of 52 cotton genotypes, labelled as Bt, were collected from various farmers and seed dealers. An immunoblot strip test was carried out, which showed that only 0·86 of the samples collected were synthesizing Cry1Ac toxin. According to multiplexed polymerase chain reaction (PCR) results, 0·86 of the genotypes tested were positive for the Mon531 event (an ‘event’ is a specific genetic modification in a specific species) and 0·14 were negative for any transgene. Transcript analysis of transgenes in positive genotypes by real-time Rt-PCR confirmed the synthesis of mRNA in all genotypes but with significant variation. The concentration of Bt toxin revealed by enzyme linked immunosorbent assay (ELISA) showed that only 0·02 genotypes had the reported optimum level. The real-time PCR and ELISA results further confirmed the attenuation of transgene expression at transcriptional and translational level by various internal and external factors. The same type of event was found in all genotypes, with significant variation in toxin level, revealing the impact of genetic background on transgene expression. The findings support the recommendation to improve the existing quality criteria for transgenic cotton variety approval and certification in Pakistan, with the inclusion of toxin concentration in the list of parameters to be considered.


2012 ◽  
Vol 11 (2) ◽  
pp. 1
Author(s):  
B. A. Jarullah, J. Aed Gati, and A. Saleh

The current study was conducted to investigate the prevalence of BVD virus in Basrah and Nassirya city by using ELISA and RT-PCR. Two hundreds and eighty two samples of non vaccinated cattle sera samples collected from two regions of Iraq (188 samples from Nassirya city and 92 samples from Basrah city). Samples tested by Enzyme Linked Immunosorbent Assay (ELISA) antigen capture. Positive results were 20 samples ( 8 sample in Thi-Qar and 12 positive samples from Basrah). All samples submitted to indirect ELISA(IDEXX HerdCheck ELISA )for detect BVDV antibodies .Genotyping of all 20 positive samples to antigen detection were tested by Real time PCR, using Cador BVDV ½ kit, after extraction of virus RNA by QIAamp mini kit. The results revealed that there were 20 positive sample according to direct ELISA(Ag detection), while 66 sample were positive to indirect ELISA, as well as, the result of RT-PCR showed that there were two sample positive to BVDV type-1 (one sample form each city).Key words: BVDV, Genotype, ELISA, Iraq, Real time PCR.


2021 ◽  
Vol 15 (1) ◽  
pp. e0008926
Author(s):  
Raphael Awah Abong ◽  
Glory Ngongeh Amambo ◽  
Ali Ahamat Hamid ◽  
Belinda Agbor Enow ◽  
Amuam Andrew Beng ◽  
...  

Background The impact of large scale Mass Drug Adminstration (MDA) of ivermectin on active onchocerciasis transmission by Simulium damnosum, which transmits the parasite O. volvulus is of great importance for onchocerciasis control programmes. We investigated in the Mbam river system area, the impact of MDA of ivermectin on entomological indices and also verify if there are river system factors that could have favoured the transmission of onchocerciasis in this area and contribute to the persistence of disease. We compared three independent techniques to detect Onchocerca larvae in blackflies and also analyzed the river system within 9 months post-MDA of ivermectin. Method Simulium flies were captured before and after 1, 3, 6 and 9months of ivermectin-MDA. The biting rate was determined and 41% of the flies dissected while the rest were grouped into pools of 100 flies for DNA extraction. The extracted DNA was then subjected to O-150 LAMP and real-time PCR for the detection of infection by Onchocerca species using pool screening. The river system was analysed and the water discharge compared between rainy and dry seasons. Principal findings We used human landing collection method (previously called human bait) to collect 22,274 adult female Simulium flies from Mbam River System. Of this number, 9,134 were dissected while 129 pools constituted for molecular screening. Overall biting and parous rates of 1113 flies/man/day and 24.7%, respectively, were observed. All diagnostic techniques detected similar rates of O. volvulus infection (P = 0.9252) and infectivity (P = 0.4825) at all monitoring time points. Onchocerca ochengi larvae were only detected in 2 of the 129 pools. Analysis of the river drainage revealed two hydroelectric dams constructed on the tributaries of the Mbam river were the key contributing factor to the high-water discharge during both rainy and dry seasons. Conclusion Results from fly dissection (Microscopy), real-time PCR and LAMP revealed the same trends pre- and post-MDA. The infection rate with animal Onchocerca sp was exceptionally low. The dense river system generate important breeding sites that govern the abundance of Simulium during both dry and rainy seasons.


2005 ◽  
Vol 12 (11) ◽  
pp. 1322-1327 ◽  
Author(s):  
Jennifer M. Scotter ◽  
Stephen T. Chambers

ABSTRACT The performance of different in vitro diagnostic tests for the diagnosis of invasive aspergillosis (IA) was investigated in a transiently neutropenic rat model. Rats were immunosuppressed with cyclophosphamide and then inoculated intravenously with 1.5 × 104 CFU Aspergillus fumigatus spores. Animals were then either treated with caspofungin acetate, 1 mg/kg/day for 7 days, or not treated. PCR-enzyme-linked immunosorbent assay (ELISA), real-time PCR, and galactomannan (GM) detection were performed on postmortem blood samples, along with culture of liver, lung, and kidney homogenate. Caspofungin-treated animals showed a decrease in residual tissue burden of  A. fumigatus from organ homogenate compared to untreated animals (P < 0.002). PCR-ELISA returned positive results for 11/17 animals treated with antifungal agents and for 10/17 untreated animals. Galactomannan was positive in 8/17 caspofungin-treated animals and 4/17 untreated animals. Real-time PCR was positive in 2/17 treated and 3/17 untreated animals. This study demonstrates that PCR-ELISA is a more sensitive test than either GM detection (P = 0.052) or real-time PCR (P < 0.01) for diagnosis of IA but that any of the three tests may return false-negative results in cases of histologically proven disease. Galactomannan indices from animals treated with antifungal agents showed a trend (P = 0.1) towards higher levels than those of untreated animals, but no effect was observed with PCR-ELISA indices (P = 0.29). GM detection, as previously described, may be enhanced by the administration of caspofungin, but PCR-ELISA appears not to be affected in the same way. We conclude that PCR-ELISA is a more sensitive and reliable method for laboratory diagnosis of IA.


Plant Disease ◽  
2009 ◽  
Vol 93 (6) ◽  
pp. 649-659 ◽  
Author(s):  
Neil C. Gudmestad ◽  
Ipsita Mallik ◽  
Julie S. Pasche ◽  
Nolan R. Anderson ◽  
Kasia Kinzer

Clavibacter michiganensis subsp. sepedonicus, causal agent of bacterial ring rot (BRR) of potato (Solanum tuberosum), is a globally important quarantine pathogen that is managed in North America using zero tolerance regulations in the certified seed industry. C. michiganensis subsp. sepedonicus is well documented to cause symptomless infections in potato, contributing to its persistence in certified seed stocks. Reliable laboratory methods to detect symptomless infections with a high degree of sensitivity could assist in the reduction of inoculum in certified seed potato stocks. A real-time polymerase chain reaction (PCR) assay was developed using the cellulase A (CelA) gene sequence as the basis for primer design. CelA primers were specific to C. michiganensis subsp. sepedonicus grown in vitro and did not detect any other coryneform bacteria or potato pathogenic bacteria but did detect 69 strains of C. michiganensis subsp. sepedonicus. The CelA real-time PCR assay was more sensitive than immunofluorescence (IFA) and Cms50/72a PCR assays in detecting C. michiganensis subsp. sepedonicus in infected potato tuber cores blended with healthy tuber cores in simulated seed lot contamination experiments. CelA primers detected nonmucoid and mucoid strains with equivalent sensitivity. In naturally infected seed lots, CelA PCR primers also were more sensitive in detecting symptomless infections of C. michiganensis subsp. sepedonicus in seed tubers prior to planting compared to Cms50/72a PCR primers, IFA, and enzyme-linked immunosorbent assay. A real-time PCR format using the newly developed CelA primers proved to be a very robust detection tool for C. michiganensis subsp. sepedonicus with the added advantage of detecting only virulent strains of the ring rot bacterium.


2009 ◽  
Vol 75 (19) ◽  
pp. 6331-6339 ◽  
Author(s):  
Amanda B. Herzog ◽  
S. Devin McLennan ◽  
Alok K. Pandey ◽  
Charles P. Gerba ◽  
Charles N. Haas ◽  
...  

ABSTRACT Used for decades for biological warfare, Bacillus anthracis (category A agent) has proven to be highly stable and lethal. Quantitative risk assessment modeling requires descriptive statistics of the limit of detection to assist in defining the exposure. Furthermore, the sensitivities of various detection methods in environmental matrices are vital information for first responders. A literature review of peer-reviewed journal articles related to methods for detection of B. anthracis was undertaken. Articles focused on the development or evaluation of various detection approaches, such as PCR, real-time PCR, immunoassay, etc. Real-time PCR and PCR were the most sensitive methods for the detection of B. anthracis, with median instrument limits of detection of 430 and 440 cells/ml, respectively. There were very few peer-reviewed articles on the detection methods for B. anthracis in the environment. The most sensitive limits of detection for the environmental samples were 0.1 CFU/g for soil using PCR-enzyme-linked immunosorbent assay (ELISA), 17 CFU/liter for air using an ELISA-biochip system, 1 CFU/liter for water using cultivation, and 1 CFU/cm2 for stainless steel fomites using cultivation. An exponential dose-response model for the inhalation of B. anthracis estimates of risk at concentrations equal to the environmental limit of detection determined the probability of death if untreated to be as high as 0.520. Though more data on the environmental limit of detection would improve the assumptions made for the risk assessment, this study's quantification of the risk posed by current limitations in the knowledge of detection methods should be considered when employing those methods in environmental monitoring and cleanup strategies.


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