322,953 research outputs found
Diarrea neonatale bovina : Escherichia coli e il fenomeno dell’antibiotico-resistenza
No full textEscherichia coli is a normal inhabitant of the gastrointestinal tract of humans and animals. Several highly adapted clones have acquired specific virulence characters and have become pathogenic. Pathotypes of E.coli represent the main cause of health problems and economical losses in calves. In the last years E. coli strains resistant to multiple drugs have been found, especially in calves affected by neonatal diarrhoea. Aim of the work was to evaluate the trend of antibiotic resistance of some E. coli strains isolated from calves. Results show a significant prevalence of multi antibiotic resistance in E. coli strains. Furthermore, the increasing level of resistance to antimicrobial agents important in treating human diseases, such as cephalospotins and fluoroquinolones, may represent a significant public health concern
Prevalence of feline bartonellosis and multilocus sequence typing of Bartonella henselae isolates in urban stray cats living in Milan, Italy
No full textCat scratch disease is a worldwide zoonosis caused predominatly by Bartonella henselae and in a lesser extent by B. clarridgeiae. Cats are the natural reservoir and vectors for B. henselae and B. clarridgeiae infections in humans. Genetic heterogeneity of B. henselae strains has been reported and multiple sequence types (STs) have been identified by the use of multilocus sequence typing (MLST). Particular sequence types have been more frequently associated with zoonosis than others. The aim of this study was to evaluate the prevalence of B. henselae and B. clarridgeiae infection in stray cats from Milan, Italy and to explore the genotypes of the B. henselae population for the evaluation of the potential risk of transmission to humans. Whole blood samples collected from 89 stray cats were cultured and analyzed by PCR. Sequence types of the feline B. henselae isolates were delineated using MLST. Bartonella henselae was detected in four (4.5%) cats and B. clarridgeiae was detected in one (1.1%) cat by PCR on blood samples. Coinfection by B. henselae type I and type II was identified in one cat. Four B. henselae isolates were cultured and were characterized as ST1 (2/4), ST5 (1/4) and ST8 (1/4), that are more commonly regarded as human associated or zoonosis associated STs. Typical feline associated B. henselae STs were not observed. Despite the low prevalence of B. henselae infection in stray cats from Milan, further investigation are needed to assess the risk for human health
Clinicopathological and Molecular Analysis of Aqueous Humor for the Diagnosis of Feline Infectious Peritonitis
No full textBackground: This study was designed to assess the diagnostic utility for FIP of cytology, protein measurement and RT-PCR for feline coronaviruses (FCoV) on aqueous humor (AH), since little information is currently available. Methods: AH samples (n = 85) were collected post-mortem from 13 cats with effusive FIP (E-FIP), 15 with non-effusive FIP (NE-FIP) and 16 without FIP, to perform cytology (n = 83) and RT-PCR (n = 66) and to calculate their sensitivity, specificity and positive and negative likelihood ratios (LR+ and LR-). The protein concentration was measured on 80 fluids. Results: The proportion of RT-PCR positive samples did not differ among groups, while positive cytology was more frequent in samples with FIP (p = 0.042) or positive RT-PCR (p = 0.007). Compared with other groups, the protein concentration was higher in samples with NE-FIP (p = 0.017), positive RT-PCR (p = 0.005) or positive cytology (p < 0.001). The specificity of cytology together with RT-PCR, cytology alone, RT-PCR alone and cytological proteinaceous background were 90.0%, 84.6%, 70.0%, 61.5%, and the LRs 3.48, 2.65, 1.83, 1.64, respectively. However, their sensitivities were low (34.8-63.0%) and their LR- high (0.60-0.72). Conclusions: Based on the LR+, cytology and/or RT-PCR may support the diagnosis when the pre-test probability of FIP is high. The concentration of intraocular protein is a promising marker, especially in NE-FIP
A Reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for feline coronavirus
No full textBACKGROUND
Loop-mediated isothermal amplification (LAMP) is a gene amplification technique that amplifies DNA in only one hour and under isothermal conditions, using a DNA polymerase with strand displacement activityand six primers targeting eight regions of the template sequence.
AIM OF THE WORK
The aim of this study was to develop a reverse transcription loop-mediated isothermal amplification assay for a rapid and inexpensive detection of feline coronavirus (FCoV).
METHODS
Six primers binding the 3' untranslated region (3'UTR) of the FCoV were designed. Thirty-two samples of RNA from cats (11 feces, 8 effusions, 9 blood samples and 4 tissues) were analyzed and a nested reverse transcription polymerase chain reaction (nRT-PCR) targeting the 3'UTR was also performed. The reaction mixture was incubated in a thermocycler at 63°C for 1 hour followed by 10 minutes at 80°C. LAMP results were evaluated both after electrophoresis migration on agarose gel stained with ethidium bromide and by naked eye after the addition of the hydroxynaphtol blue (HNB) dye. Results were compared with the nRTPCR, considered the gold standard.
RESULTS
The specificity was 100% on all specimens, while the sensitivity was 100% only on tissues. The overall sensitivity was 52.4% and 50% with gel electrophoresis and HNB, respectively. Discrepant results between the two visualization methods were recorded.
DISCUSSION/CONCLUSIONS
Except for tissues, the low sensitivity of the LAMP assay for FCoV limits a clinical application of this method. Additional experiments are needed in order to assess the analytical sensitivity and to develop a quantitative visualization technique
Feline infectious peritonitis (FIP) and coronavirus disease 19 (COVID-19): Are they similar?
No full textSARS-CoV-2 has radically changed our lives causing hundreds of thousands of victims worldwide and influencing our lifestyle and habits. Feline infectious peritonitis (FIP) is a disease of felids caused by the feline coronaviruses (FCoV). FIP has been considered irremediably deadly until the last few years. Being one of the numerous coronaviruses that are well known in veterinary medicine, information on FCoV could be of interest and might give suggestions on pathogenic aspects of SARS-CoV-2 that are still unclear. The authors of this paper describe the most important aspects of FIP and COVID-19 and the similarities and differences between these important diseases. SARS-CoV-2 and FCoV are taxonomically distant viruses, and recombination events with other coronaviruses have been reported for FCoV and have been suggested for SARS-CoV-2. SARS-CoV-2 and FCoV differ in terms of some pathogenic, clinical and pathological features. However, some of the pathogenic and immunopathogenic events that are well known in cats FIP seem to be present also in people with COVID-19. Moreover, preventive measures currently recommended to prevent SARS-CoV-2 spreading have been shown to allow eradication of FIP in feline households. Finally, one of the most promising therapeutic compounds against FIP, GS-441524, is the active form of Remdesivir, which is being used as one therapeutic option for COVID-19
Reverse transcriptase loop-mediated isothermal amplification for the detection of feline coronavirus
No full textThe Feline coronavirus (FCoV) is the etiological agent of feline infectious peritonitis (FIP), a lethal disease of felids. The role of molecular methods is controversial for the diagnosis of FIP, while essential for the identification of the shedders. Thus, a fast and inexpensive method for the detection of FCoV could be beneficial, especially in multicat environments. A reverse transcription loop mediated isothermal amplification (RT-LAMP) assay was developed. RNA extraction and RT-nPCR for FCoV were performed on thirty-two samples (11 faeces, 9 blood, 8 effusions, and 4 lymph nodes) collected from 27 cats. Six RT-LAMP primers were designed from the same conserved region of RT-nPCR, and the assay was run at 63 °C for one hour. Results were evaluated through both agarose gel run and hydroxynapthol blue (HNB) dye and then compared with RT-nPCR results for the assessment of sensitivity and specificity. The overall specificity was 100%, but the sensitivity was 50% and 54.5% for agarose gel and HNB respectively. Therefore, RT-LAMP seems optimal to confirm the presence of the virus, but not applicable to exclude it
Microarray per l'identificazione simultanea di Equid herpesvirus, West Nile virus e Borna disease virus in equini
No full textTransition cow: non-specific immune response
No full textThe immune system consists of cells and their products, whose prime function is the protection of the host against pathogens and it can also acts as an accommodation device to facilitate the development of relatively peaceful associations with foreign organisms which, in some instances and especially in ruminants, could be or could become symbiotic. The immune system during pregnancy and the exchange of immunity from mother to newborn are unique events in immunological physiology. The peripartum hormonal changes contribute to impaired immune function. The physical and metabolic stresses of pregnancy, calving and lactation contribute to the decrease of host resistance and the subsequent increase in disease incidence. Pregnancy and peripartum period result in nonspecific immunosuppression of the dairy cow. The magnitude and timing of this reduction depend on many factors such as not adequate hygienic and sanitary management, not appropriate feed and housing and genetic differences. In this paper we deal with the evaluation of some parameters of non-specific immunity in dairy cattle in order to depict important features of the immune reactivity during the transition period and to make possible a preventive treatment. Lysozime concentration, serum bactericidal activity, serum proteins elettrophoretic profile, aptoglobin and complement with further analysis of non specific cellular immunological parameters could determine the effects of pregnancy, parturition and lactation on non-specific immune response especially during the peripartum period and may suggest the presence of not adequate hygienic and sanitary condition of the herd and/or not appropriate feed and management approach
Antibiotic resistance and patogenicity in Escherichia coli
No full textEscherichia Coli is a Gram negative bacterium, widely studied because it represents an integrating part of the human enteric flora, even if various strains are pathogen. Moreover such strains are zoonotic agents and they can be isolate also in ruminants in which cause diarrhoea and edema. Human infection occurs via fecal-oral pathway and animals are reservoirs for this human pathogen. Lesions are characterized by intimate bacterial attachment to the host cell membrane and the destruction of microvilli at the site of bacterial adherence, caused by the accumulation of signal proteins leading to the rearrangement of cytoskeletal proteins, in particular, filamentous actin, resulting in pedestal formation at the apical cell membrane.
In recent data, the evaluation of membrane proteins, phosphoproteome and the study of
oxidative stress, can contribute to understanding the phenomenon of antibiotic resistance to
molecular level and to define new strategies for the design of highly selective therapeutic
agents.
Evaluation of protein profiles respect to various mechanisms of stress, i.e. the resistance to
antibiotics or the modification related to the antibiotic resistance, represents a valid and
integrating approach for the study of new therapeutic strategies.
In the current study, comparative proteomics was applied to identify changes in proteins
responsible for antibiotic resistance in different in vivo isolates Escherichia coli. In particular
it has been studied strains with same virulence factors, but an antibiotic profile completely
different, isolates from different organs of the same animal
Caratterizzazione genotipica e sensibilità agli antibiotici degli isolamenti di Escherichia coli da infezioni urinarie (UTI) delle scrofe
No full textI ceppi di E. coli isolati da UTI delle scrofe sono stati analizzati in PCR per l’identificazione di diversi fattori di virulenza e del gruppo filogenetico di appartenenza. La
maggior parte dei ceppi è stata positiva per le fimbrie tipo 1 e per l’aerobactina. Gli isolamenti
differiscono da quelli dell’uomo per il profilo di adesione e per l’emolisina: le fimbrie tipo
P e tipo S, così come l’emolisina, sono meno frequenti nei ceppi suini che, a differenza di
quelli umani sono, per lo più, classificati nei gruppi filogenetici A e B1. Di tutti gli isolamenti
è stata verificata l’antibiotico-sensibilità nei confronti dei principi attivi più frequentemente
utilizzati per la terapia delle UTI nelle scrofe.Porcine E. coli strains have been analyzed by PCR for the presence of several
virulence factors and identified with regard to placement in the phylogenetic groups. The
majority of the tested strains harboured type 1 fimbriae and aerobactin. The strains were quite
different from human uropathogenic ones about the adhesion profile and haemolysin, since P
and S fimbriae were significantly lower in porcine strains as was haemolysin. Differences with
human strains were also observed related to phylogenetic groups, since our strains belonged
to E. coli clonal groups A and B1. All isolates were tested for sensitivity to antibiotics most
frequently used in the treatment of UTI in sows
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