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Bovine mastitis, an evolving disease: Application of infrared thermography for the diagnosis of subclinical forms and presence of methicillin resistant Stahpylococcus aureus in dairy farms
Full text linkSubclinical mastitis in dairy cows is a big economic loss for farmers. The monitoring of subclinical mastitis is usually performed through Somatic Cell Count (SCC) in farm but there is the need of new diagnostic systems able to quickly identify cows affected by subclinical infections of the udder.
In the last years the fight against mastitis has seen the emergence of mastitis cases caused by multiresistant bacteria which poorly respond to antibiotic treatments. One of the most important pathogens because of this aspects of antimicrobial resistance and for its potential as zoonotic pathogen is the Methicillin Resistant Staphylococcus aureus (MRSA).
The aim of this thesis is to investigate two important aspects of bovine mastitis, in a first study we evaluated the potential of infrared thermography in the diagnosis of subclinical mastitis and in a second study it was investigated the presence and the prevalence of MRSA in the territory of the Veneto Region.
In the first study we evaluated the udder health status of 98 Holstein Friesian dairy cows with high SCC in 4 farms. From each cow a sample of milk was collected from all the functional quarters and submitted to bacteriological culture, SCC and Mycoplasma spp. culture. Thermographic images were taken from each functional udder quarter and nipple. Pearson’s correlations and Analysis of Variance were performed in order to evaluate the different diagnostic techniques. The most frequent pathogen isolated was Staphylococcus aureus followed by Coagulase Negative Staphylococci (CNS), Streptococcus uberis, Streptococcus agalactiae and others. The Somatic Cell Score (SCS) was able to discriminate (p<0.05) cows positive for a pathogen from cows negative at the bacteriological culture except for cows with infection caused by CNS. Infrared thermography was correlated to SCS (p<0.05) but was not able to discriminate between positive and negative cows. Thermographic imaging seems to be promising in evaluating the inflammation status of cows affected by subclinical mastitis but seems to have a poor diagnostic value.
In the second study we investigated the presence and prevalence of MRSA in the Veneto Region. In order to do that 70 farms holding at least 100 animals were selected. In each farm were collected composite milk samples and nasal swabs from lactating cows.
The samples collected were submitted for specific bacteriological culture for MRSA. The isolated strains were characterized to discover the presence of genes codifying for the resistance to several antimicrobial classes and to evaluate the epidemiological characteristics.
15 MRSA strains were isolated from 6 farms. 13 from milk samples and 2 from nasal swabs. The prevalence found was similar to what obtained in previous studies conducted in other European countries. The prevalence inside the farms was low and no farm was simultaneously positive for MRSA in milk and in nasal swabs. The low prevalence of colonization of the upper respiratory tract in somewhat surprising, considered the high prevalence of colonization in veal calves farms, in which are raised male calves coming from dairy farms.
The genetic characterization has determined the belonging of the isolated strains to well known clones (CC1, CC97, CC398) adapted to livestock (Livestock Associated MRSA) and different from the more dangerous strains associated to healthcare environment (Hospital Associated MRSA). The clones found has anyway already proven their zoonotic potential and represent not only a new challenge in the fight against bovine mastitis but also a risk for the exposed personnel
Survey of Methicillin-resistant coagulase positive Staphylococcus spp. carriage in healthy dogs and dogs with skin disease
Full text linkCanine skin diseases (SD) are very common in the veterinary practice and are often complicated by recurrent bacterial infection. Affected dogs usually need multiple cycles of antibiotic treatments (AT) that can lead to development of multidrug resistant strains [1]. Coagulase-positive staphylococci (CPS) are the most often isolated pathogens from canine SD.
The aim of this study is to assess the prevalence of multidrug and methicillin resistant coagulase-positive staphylococci (MRScp) isolated from healthy dogs and dogs with SD, and to evaluate the correlation with clinical scores and previous AT. Forty-nine dogs were enrolled: 25 healthy and 24 with SD. Clinical history and previous AT were recorded. After a complete physical examination, clinical scores (CADESI-3 and pruritus) were calculated. Skin swabs from mouth, ear, genitalia, axilla and skin lesions, when present, were cultured in a nutrient and in a selective medium for MRScp. Suspected Staphylococcus colonies were identified by Maldi-Tof MS and specific PCR; methicillin resistance was confirmed by a PCR targeting mecA gene. Susceptibility tests and genetic typing, including spa-typing, SCCmec-typing and MLST were performed on isolates. Normal distribution of data was tested with Shapiro-Wilk test. Data were analyzed using ANOVA and z-test if normally distributed, otherwise with Mann-Whitney Test. Correlations between bacterial resistance and clinical scores or previous AT were assessed by Spearman test. P-value <0.05 was considered significant.
Ninety-five strains of CPS were isolated from 229 samples. A total of 13/95 strains were MRScp and were identified as Staphylococcus pseudintermedius. Among them, 10 were multidrug resistant and two were isolated from healthy dogs. The Sequence Type 71, spa-type t02 e SCCmec type II-III, which represents the main clonal strain in Europe [2], was the most frequently identified genetic type (11/13) also in this study. Staphylococci were more commonly isolated from axilla, genitalia and ear conduct of dogs with SD compared with healthy dogs (p<0.001). Four out of the 6 MRScp positive dogs had received AT in the previous 6 months. No significant correlations between clinical scores or previous AT and methicillin resistance was found.
Although the low number of dogs included in the study could have affected the results of the investigated correlations, this study confirms the role of Staphylococcus pseudintermedius in canine pyoderma and shows that pet dogs may play a significant role as MRScp carriers. Furthermore, close attention should be also paid also to the control of healthy dogs
A systematic review of human coronaviruses survival on environmental surfaces
No full textThe current pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led people to implement preventive measures, including surface disinfection and use of alcohol-based hand gel, in order to avoid viral transmission via fomites. However, the role of surface transmission is still debated. The present systematic review aims to summarize all the evidence on surface survival of coronaviruses infecting humans. The analysis of 18 studies showed the longest coronavirus survival time is 28 days at room temperature (RT) on different surfaces: polymer banknotes, vinyl, steel, glass, and paper banknotes. Concerning SARS-CoV-2 human infection from contaminated surfaces, dangerous viral load on surfaces for up to 21 days was determined on polymer banknotes, steel, glass and paper banknotes. For viruses other than SARS-CoV-2, the longest period of survival was 14 days, recorded on glass. Environmental conditions can affect virus survival, and indeed, low temperatures and low humidity support prolonged survival of viruses on contaminated surfaces independently of surface type. Furthermore, it has been shown that exposure to sunlight significantly reduces the risk of surface transmission. Although studies are increasingly investigating the topic of coronavirus survival, it is difficult to compare them, given the methodology differences. For this reason, it is advisable to define a reference working protocol for virus survival trials, but, as an immediate measure, there is also a need for further investigations of coronavirus survival on surfaces
Inframed thermography as a diagnostic tool for early detection of subclinical mastitis in dairy cows.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Prevalence of SARS-CoV-2 RNA on inanimate surfaces: a systematic review and meta-analysis
No full textCoronavirus disease (COVID-19) is a respiratory disease affecting many people and able to be transmitted through direct and perhaps indirect contact. Direct contact transmission, mediated by aerosols or droplets, is widely demonstrated, whereas indirect transmission is only supported by collateral evidence such as virus persistence on inanimate surfaces and data from other similar viruses. The present systematic review aims to estimate SARS-CoV-2 prevalence on inanimate surfaces, identifying risk levels according to surface characteristics. Data were obtained from studies in published papers collected from two databases (PubMed and Embase) with the last search on 1 September 2020. Included studies had to be papers in English, had to deal with coronavirus and had to consider inanimate surfaces in real settings. Studies were coded according to our assessment of the risk that the investigated surfaces could be contaminated by SARS-CoV-2. A meta-analysis and a metaregression were carried out to quantify virus RNA prevalence and to identify important factors driving differences among studies. Thirty-nine out of forty retrieved paper reported studies carried out in healthcare settings on the prevalence of virus RNA, five studies carry out also analyses through cell culture and six tested the viability of isolated viruses. Overall prevalences of SARS-CoV-2 RNA on high-, medium- and low-risk surfaces were 0.22 (CI95 [0.152-0.296]), 0.04 (CI95 [0.007-0.090]), and 0.00 (CI95 [0.00-0.019]), respectively. The duration surfaces were exposed to virus sources (patients) was the main factor explaining differences in prevalence
Evaluation of the udder health status in subclinical mastitis affected dairy cows through bacteriological culture, somatic cell count and thermographic imaging.
No full textSubclinical mastitis in dairy cows is a big economic loss for farmers. The monitoring of subclinical mastitis is usually performed through Somatic Cell Count (SCC) in farm but there is the need of new diagnostic systems able to quickly identify cows affected by subclinical infections of the udder. The aim of this study was to evaluate the potential application of thermographic imaging compared to SCC and bacteriological culture for infection detection in cow affected by subclinical mastitis and possibly to discriminate between different pathogens. In this study we evaluated the udder health status of 98 Holstein Friesian dairy cows with high SCC in 4 farms. From each cow a sample of milk was collected from all the functional quarters and submitted to bacteriological culture, SCC and Mycoplasma spp. culture. A thermographic image was taken from each functional udder quarter and nipple. Pearson's correlations and Analysis of Variance were performed in order to evaluate the different diag..
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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