Efficacy of vaccination on Staphylococcus aureus and coagulase-negative staphylococci intramammary infection dynamics in 2 dairy herds.

AbstractThe aim of this study was to evaluate vaccine efficacy of a commercial vaccine (Startvac, Hipra Spain) aimed at reducing intramammary infections (IMI) with Staphylococcus aureus and coagulase-negative staphylococci under field conditions. During the 21-mo duration of the study, 1,156 lactations from 809 cows were enrolled in 2 herds. During the first phase of the trial, all cows that were due to calve were vaccinated until approximately 50% of cows in the milking herd were vaccinated (at ~6mo). At that point, when 50% vaccination coverage was reached, cows that were due to calve were randomly assigned to be vaccinated or left as negative controls. Cure rate, rate of new infection, prevalence, and duration of infections were analyzed. Vaccination resulted in a moderate reduction in incidence of new staphylococcal IMI and a more pronounced reduction in duration of IMI associated with reduction of the basic reproduction ratio of Staph. aureus by approximately 45% and of coagulase-negative staphylococci by approximately 35%. The utilization of vaccine in combination with other infection-control procedures, such as excellent milking procedures, treatment, segregation, and culling of known infected cattle, will result in an important reduction in incidence and duration of intramammary staphylococcal infections

SUSCEPTIBILITY TO MAIN ANTIBIOTICS OF GRAM-NEGATIVE BACTERIA FROM BOVINE MASTITIS IN ITALIAN HERDS

Introduction .The incorrect use of antibiotics in veterinary medicine has contributed to reduce the pathogen susceptibility to antibiotics. Through direct contact or food chain the resistant bacteria can be transferred to humans (2). In dairy cows, differently from other production animals, milk discharge during antibiotic administration and related withdrawal time has a direct economical effect on production. This issue has determined a more responsible use of antibiotics. Moreover, in mastitis field antibiotics are used mainly to treat clinical cases and not for prophylaxis, except when blanket dry-cow therapy is applied. For this reason monitoring susceptibility to antibiotic-resistance in dairy cows could identify different trend respect to other food animals. Gram-negative bacteria are frequently cause of clinical mastitis and, as part of enteric flora, they are subjected to the selective pressure of systemic drug treatments. For this reason they are subjected to specific monitoring program for antibiotic resistance. This paper describes a study about in vitro antimicrobial susceptibility of Gram negative bacteria isolated from bovine clinical mastitis in Northern Italy. Materials and Methods Among Gram negative bacteria isolated from bovine clinical mastitis in Northern Italy during the years 2010/2011, 99 isolates were selected: 53 E.coli, 28 Klebsiella spp, 14 Serratia spp, 2 Enterobacter spp. e 2 Citrobacter spp. Pathogens isolation was carried out in milk samples following the National Mastitis Council guideline (3). Species identification was performed through commercial kits API 20 and API 20 NE (Biomerieux Marcy l\u2019Etoile, France). In vitro antimicrobial susceptibility was evaluated using minimal inhibitory concentrations (MICs) broth dilution test, according to the procedure described in Clinical and Laboratory Standards Institute (CLSI) guideline. CLSI resistance breakpoints were used (1). Sensititre susceptibility plates were used according to supplier instructions (Trek Diagnostics System, East Grinstead, UK). The antibiotics used are listed in table 1. After incubation the plates were manually read recording the last dilution able to inhibit bacterial growth. Results and Discussion The 36% of tested E. coli resulted resistant towards ampicillin, while using penicillins associated to clavulanic acid the percentage of resistant isolates declined to 7,5%. Serratia spp isolates demonstrated a higher resistance level to amoxicillin/clavulanic acid, with susceptibility reduced to 74%. Cephalosporins confirmed a very high efficacy in the regards of E coli, as 94,3% of isolates were susceptible to 1st generation cephalosporins and 100% to 3rd generation (ceftiofur and cefpodoxime). Similar results were obtained for Klebsiella spp, while all Serratia spp tested isolates revealed some resistance to 1st generation cephalosporins, maintaining susceptibility to 3rd generation cephalosporins. Among drugs active specifically towards Gram-negatives bacteria, chloramphenicol and sulfonamide associated with trimethoprim demonstrated high efficacy to all tested species. Average susceptibility was 85% for sulfonamide with trimethoprim, and 95% for chloramphenicol. Finally, only one E. coli isolate resulted resistant to fluoroquinolons with an intermediate MIC for marbofloxacin and enrofloxacin, while all the others 98 Gram-negative isolates tested were susceptible (MIC < 0,5 \uf06dg/mL). Complete data are shown in table 1. Table 1. In vitro susceptibility and resistance of E. coli and Klebsiella spp., Serratia spp., Enterobacter spp. and Citrobacter spp. (joined in \u201cother Gram-negatives\u201d) towards tested antibiotics. Antibiotics Sensible E. coli (%) Resistant E. coli (%) Sensible other Gram-negatives (%) Resistant other Gram-negatives (%) Ampicillin 64,2% 35,8% 30,4% 69,6% Amoxicillin/clavulanic acid 92,5% 7,5% 73,9% 26,1% Amikacin 100,0% 0,0% 100,0% 0,0% Cefpodoxime (3rd gen. Ceph.) 100,0% 0,0% 100,0% 0,0% Ticarcillin/clavulanic acid 94,3% 5,7% 89,1% 10,9% Sulfonamide/thrimethoprim 86,8% 13,2% 89,1% 10,9% Cefazolin (1\ub0st gen. Ceph.) 94,3% 5,7% 63,0% 37,0% Gentamicin 100,0% 0,0% 100,0% 0,0% Imipenem 100,0% 0,0% 100,0% 0,0% Penicillin 0,0% 100,0% 0,0% 100,0% Doxiciclin 75,5% 24,5% 71,7% 28,3% Ceftiofur (3rd gen. Ceph.) 100,0% 0,0% 100,0% 0,0% Marbofloxacin 98,1% 1,9% 100,0% 0,0% Enrofloxacin 98,1% 1,9% 100,0% 0,0% Chloramphenicol 94,3% 5,7% 97,8% 2,2% In conclusion, this study demonstrates that Gram-negative bacteria commonly isolable in case of mastitis are susceptible to most antibiotics, included fluoroquinolons, sulfonamide and chloramphenicol. Reduced susceptibility to some beta-lactams in E.coli are avoided associating clavulanic acid, an inhibitor of beta-lactamases. Serratia spp. is an exception probably due to specific beta-lactamases produced, which are resistant to inhibitors. This findings confirm the importance of milk culture in mastitis cases to achieve an etiological diagnosis, that allows to choose treatment or culling for chronically infected animals. The aims of treatment procedures in farm animal should be avoiding abuse of antibiotic therapy and reducing selection of resistant strains. Periodical survey and detection of resistance phenomenon are recommended. References 1. CLSI. (2008). Performances standards for antimicrobial disk and dilution susceptibility tests for bacteria isolated from animals: approved standard \u2013 third edition CLSI document M31-A3. CLSI Wayne, PA, (USA): Clinical and Laboratory Standard Institute. 2. Friedman D.B., Kanwat CP, Headrick ML, Patterson NJ, Neely JC, Smith LU. (2007) Importance of prudent antibiotic use on dairy farms in south carolina: a pilot project on farmers\u2019 knowledge, attitudes and practices. Zoonoses Public Health. 54, 366\u2013375. 3.NATIONAL MASTITIS COUNCIL (1999). Laboratory and field handbook on bovine mastitis. National Mastitis Council, Madison WI

NMR chemistry analysis of red blood cell constituents in normal subjects and lithium-treated psychiatric patients

Red blood cells from 18 lithium carbonate-treated patients with bipolar affective disorder and 12 normal volunteers were analyzed using 1H-nuclear magnetic resonance (NMR) spectroscopy. The spectra were analyzed for alanine, adenosine triphosphate (ATP), choline, 2,3-diphosphoglycerol, glucose, glutathione, glycine, and lactate. Significant elevations of choline and lactate were found in the lithium-treated patients compared with normal, unmedicated subjects. The elevation of lactate due to anaerobic metabolism in the red blood cells was further investigated via fluoremetric analysis and appears to be caused by blood standing at room temperature. The observed increases in red blood cell choline are sufficiently high and statistically significant to warrant additional studies on the dramatic effects of lithium on this red cell metabolite, which might be important for an understanding of its mechanism of action in psychiatric disorders.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25491/1/0000032.pd

Endocrine, cardiovascular, and behavioral responses to clonidine in patients with panic disorder

We examines adrenergic regulation in patients with panic disorder by challenging 10 patients and 14 age-matched and sex-matched controls with intravenous infusions of clonidine hydrochloride (2 [mu]g/kg), an alpha2-adrenoreceptor agonist. Growth hormone, 3-methoxy-4-hydroxyphenylglycol (MHPG), blood pressure, heart rate, and behavioral (anxiety, sedation) responses were monitored. The data replicated the previously reported finding of blunted growth hormone (GH) responses to clonidine in patients with panic disorder. Reported abnormalities in MHPG, cardiovascular, and behavioral responses of panic patients to clonidine infusion were not replicated. The robustly blunted GH response to clonidine in panic patients supports the adrenergic dysregulation hypothesis of panic disorder, but alternative interpretations of this finding are available and further study is needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29953/1/0000313.pd

Staphylococcus aureus Isolates from Bovine Mastitis in Eight Countries: Genotypes, Detection of Genes Encoding Different Toxins and Other Virulence Genes

Staphylococcus aureus is recognized worldwide as one of the major agents of dairy cow intra-mammary infections. This microorganism can express a wide spectrum of pathogenic factors used to attach, colonize, invade and infect the host. The present study evaluated 120 isolates from eight different countries that were genotyped by RS-PCR and investigated for 26 different virulence factors to increase the knowledge on the circulating genetic lineages among the cow population with mastitis. New genotypes were observed for South African strains while for all the other countries new variants of existing genotypes were detected. For each country, a specific genotypic pattern was found. Among the virulence factors, fmtB, cna, clfA and leucocidins genes were the most frequent. The sea and sei genes were present in seven out of eight countries; seh showed high frequency in South American countries (Brazil, Colombia, Argentina), while sel was harboured especially in one Mediterranean country (Tunisia). The etb, seb and see genes were not detected in any of the isolates, while only two isolates were MRSA (Germany and Italy) confirming the low diffusion of methicillin resistance microorganism among bovine mastitis isolates. This work demonstrated the wide variety of S. aureus genotypes found in dairy cattle worldwide. This condition suggests that considering the region of interest might help to formulate strategies for reducing the infection spreading

Prognostic value of DNA flow cytometry in stomach cancer: a 5-year prospective study

The role of DNA flow cytometry in the prediction of prognosis for patients with stomach cancer remains to be defined. Thus we studied prospectively the role of DNA flow cytometry as a prognosis indicator in stomach cancer patients in a high-incidence area. Between November 1990 and December 1992, primary stomach cancer tissues were obtained from the surgical specimens from 217 patients (148 male, 69 female). DNA flow cytometric analyses of DNA ploidy and S-phase fraction were performed and the results were correlated with patient survival. The median age of the patients was 55 years (range 24–78). Aneuploid cell population was found in 114 of 217 samples (53%). Tumour S-phase fraction was obtained in 96 of 103 diploid tumours (93%) and 61 of 114 aneuploid tumours (54%). After median follow-up of 66.1 months, the patients with tumours with an S-phase fraction over 17% had significantly worse survival rates than patients with tumours with S-phase fractions of lower than 8% or 8–17% (45% vs 59% and 63% of patients surviving, P = 0.007). Tumour ploidy status did not correlate with patient survival. Multivariate analyses showed that the TNM stage remained the most important prognostic indicator. The tumour S-phase fraction was also an independent prognostic indicator (relative risk 2.300, 95% CI, 1.252–4.223). Tumour S-phase fraction obtained by DNA flow cytometry is an independent prognostic indicator for the survival of the patients with stomach cancer. © 1999 Cancer Research Campaig