Occurrence and characterization of methicillin-resistant staphylococci from bovine mastitis milk samples in Finland

Background: Methicillin-resistant staphylococci (MRS) are increasingly being isolated in bovine mastitis. The aim of our study was to evaluate the occurrence of MRS in Finnish mastitis milk samples and characterize the MRS isolates using molecular methods. Results: Methicillin-resistant S. aureus (MRSA) was a rare finding in bovine mastitis in Finland. Only two out of 135 (1.5%) S. aureus isolates were positive for mec genes. One of these carried mecA and was of spa type t172, SCCmec type IV and ST375, and the other harboured mecC, being spa type t3256, and ST130. MRSA ST375 is common among human MRSA isolates in Finland, but this is the first report in the country of bovine mecC MRSA. In coagulase-negative staphylococci (CoNS) originating from bovine mastitis, methicillin resistance was more common. In the two CoNS collections studied, 5.2% (17/324) and 1.8% (2/110) of the isolates were mecA positive. Eighteen of these were methicillin-resistant S. epidermidis (MRSE), which were divided into 6 separate PFGE clusters. One pulsotype was detected in different parts of the country, indicating clonal spread. Most MRSE (13/18) were of SCCmec type IV, one was of type V and four were non-typeable. Comparison with a human staphylococcal database indicated that bovine MRSE strains were not closely related to human MRSE isolates. Conclusions: The occurrence of MRS, especially MRSA, in bovine mastitis in Finland was low. Most methicillinresistant bovine CoNS are MRSE, and we found evidence of a bovine MRSE strain that may spread clonally. This is the first report of a Finnish bovine isolate of MRSAmecC ST130. The study provides a baseline for further MRS monitoring

Occurrence of antimicrobial resistance among bacterial pathogens and indicator bacteria in pigs in different European countries from year 2002 – 2004 : the ARBAO-II study

Background: The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II) was funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003–05. The aim of this project was to establish a program for the continuous monitoring of antimicrobial susceptibility of pathogenic and indicator bacteria from food animals using validated and harmonised methodologies. In this report the first data on the occurrence of antimicrobial resistance among bacteria causing infections in pigs are reported. Methods: Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were collected from fifteen European countries in 2002–2004.Results: Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low frequency of resistance to tetracycline and trimethoprim – sulphonamide. Data for S. suis were obtained from six countries. In general, a high level of resistance to tetracycline (48.0 – 92.0%) and erythromycin (29.1 – 75.0%) was observed in all countries whereas the level of resistance to ciprofloxacin and penicillin differed between the reporting countries. Isolates from England (and Wales), France and The Netherlands were all susceptible to penicillin. In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004) and to penicillin from 8.1 – 13.0% (2004) in Poland and Portugal. Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas in healthy pigs the frequency of resistance was lower. Conclusion: Bacterial resistance to some antimicrobials was frequent with different levels of resistance being observed to several antimicrobial agents in different countries. The occurrence of resistance varied distinctly between isolates from healthy and diseased pigs, with the isolates from healthy pigs generally showing a lower level of resistance than those from diseased pigs. The study suggests that the choice of antimicrobials used for the treatment of diseased animals should preferably be based on knowledge of the local pattern of resistance

Occurrence of antimicrobial resistance among bacterial pathogens

Background: The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II) was funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003–05. The aim of this project was to establish a program for the continuous monitoring of antimicrobial susceptibility of pathogenic and indicator bacteria from food animals using validated and harmonised methodologies. In this report the first data on the occurrence of antimicrobial resistance among bacteria causing infections in pigs are reported. Methods: Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were collected from fifteen European countries in 2002–2004.Results: Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low frequency of resistance to tetracycline and trimethoprim – sulphonamide. Data for S. suis were obtained from six countries. In general, a high level of resistance to tetracycline (48.0 – 92.0%) and erythromycin (29.1 – 75.0%) was observed in all countries whereas the level of resistance to ciprofloxacin and penicillin differed between the reporting countries. Isolates from England (and Wales), France and The Netherlands were all susceptible to penicillin. In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004) and to penicillin from 8.1 – 13.0% (2004) in Poland and Portugal. Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas in healthy pigs the frequency of resistance was lower. Conclusion: Bacterial resistance to some antimicrobials was frequent with different levels of resistance being observed to several antimicrobial agents in different countries. The occurrence of resistance varied distinctly between isolates from healthy and diseased pigs, with the isolates from healthy pigs generally showing a lower level of resistance than those from diseased pigs. The study suggests that the choice of antimicrobials used for the treatment of diseased animals should preferably be based on knowledge of the local pattern of resistance

Mikrobilääkeresistenssi ja -jäämät nautatilalla - vaikutukset ympäristöön ja terveyteen (NAMI)

Tässä Ruokaviraston (ennen Elintarviketurvallisuusvirasto Evira), Luken ja SYKEn yhteisprojektissa tutkittiin mikrobilääkejäämien ja resistenttien suolistobakteerien kulkeutumista lääkityistä lypsylehmistä navettaympäristön kautta lantavarastoihin. Lisäksi arvioitiin niiden leviämistä lannan peltolevitysten välityksellä luonnon eliöihin sekä elintarviketuotantoketjussa. Projektissa tutkittiin myös anaerobisen mesofiilisen mädätyksen vaikutuksia lannassa oleviin mikrobilääkejäämiin ja resistentteihin suolistobakteereihin sekä toisaalta lannan mikrobilääkejäämien vaikutusta mädädysprosessin toimintaan. Lisäksi arvioitiin erilaisten lannan prosessointitapojen elinkaarisia ympäristövaikutuksia sekä vaikutuksia mikrobilääkejäämiin ja -resistenssiin. Resistentit ja moniresistentit suolistobakteerit kulkeutuivat lypsykarjatilalla lantavarastoihin, mutta ne eivät rikastuneet lantaketjussa. Lypsykarjan lietelannasta mitattiin hyvin pieniä pitoisuuksia mikrobilääkkeitä. Lääkittyjen eläinten sonnasta ja virtsasta taas mitattiin hoidon aikana hyvin korkeita pitoisuuksia mikrobilääkejäämiä, jolloin niistä muodostuvissa (kuivissa) lannoissa voi olla korkeita paikallisia pitoisuuksia mikrobilääkkeitä. Suomessa myös mikrobilääkkeillä lääkittyjen eläinten lannat levitetään pääosin käsittelemättöminä kasvinravinteiksi pelloille, jolloin lannan mukana voi levitä mikrobilääkejäämiä ja resistenttejä suolistobakteereita. Luonnon eliöt voivat altistua lannassa oleville mikrobilääkkeille ja resistenteille suolistobakteereille myös Suomen olosuhteissa. Lääkittyjen eläinten lantojen lannoitekäyttöä käsittelemättömänä tulisi arvioida kriittisesti. Mesofiilinen anaerobinen mädätys voi vähentää mikrobilääkejäämiä lannasta, mutta ei välttämättä hajota niitä. Se vähentää elävien suolistobakteerien määrää lannassa, mutta merkittävää vaikutusta resistenttien E. coli -bakteerien osuuteen ei havaittu. Erilaiset lannankäsittelytavat voivat kuitenkin soveltua – ravinteiden kierrätyksen ja energiantuoton lisäksi – mikrobilääkejäämien ja resistenssin torjumiseen, ja niitä tulisikin tässä tarkoituksessa tutkia tarkemmin Suomessa.I detta samprojekt mellan Livsmedelsverket (före detta Livsmedelssäkerhetsverket Evira), Luke och SYKE undersöktes spridningen av resthalter av antimikrobiella läkemedel och resistenta tarmbakterier från behandlade mjölkkor till gödsellager via ladugårdsmiljön. Därtill uppskattades spridningen till organismer i naturen via gödselspridning på åkrar samt i livsmedelskedjan. I projektet undersöktes även effekten av anaerob mesofil rötning på resthalter av antimikrobiella medel i gödsel och resistenta tarmbakterier samt även effekten av resthalter av antimikrobiella medel på rötningsprocessen. Dessutom analyserades livscykeln för miljöpåverkan av de olika gödselbearbetningsmetoderna samt effekterna på resthalter av antimikrobiella medel och resistens. Resistenta och multiresistenta tarmbakterier spreds på mjölkgården till gödsellagren, men anrikades inte i gödselkedjan. Mycket små halter av antimikrobiella medel uppmättes i mjölkkornas flytgödsel. Men mycket höga resthalter av antimikrobiella medel uppmättes i gödsel och urin medan djuren behandlades, och då kan det finnas höga lokala halter av antimikrobiella medel i deras (torr)gödsel. I Finland sprids gödsel även av antibiotikabehandlade djur till största delen obehandlad som växtnäring på åkrar, och då kan resthalter av antimikrobiella medel och resistenta tarmbakterier spridas med gödseln. Organismer i naturen kan utsättas för antimikrobiella medel i gödsel och resistenta tarmbakterier även i finländska förhållanden. Användningen av obehandlad gödsel från medicinerade djur borde utvärderas kritiskt. Mesofil anaerob rötning kan minska på mängden resthalter av antimikrobiella medel i gödseln, men bryter inte nödvändigtvis ned dem. Den minskar på mängden levande tarmbakterier i gödseln, men ingen betydande effekt på andelen resistenta E.coli-bakterier påvisades. Olika sätt att behandla gödsel kan ändå, utöver återvinning av näringsämnen och energiproduktion, lämpa sig för bekämpning av antimikrobiella resthalter och resistens, och de borde undersökas mera detaljerat i Finland i det syftet.This study was conducted by Finnish Food Authority (formerly Finnish Food Safety Authority Evira), Natural Resources Institute Finland Luke and Finnish Environment Institute SYKE in 2015–2018. The aims of the study were to examine how antimicrobial residues and antimicrobial-resistant E. coli bacteria spread via the manure chain from the dairy cows treated with antimicrobials to the farm environment and manure storages. Furthermore, the dissemination routes to the surrounding environment, ecosystems and back to the food chain in Finnish conditions were profiled. The effect of mesophilic anaerobic digestion process on the level of antimicrobial residues and antimicrobial-resistant E. coli was examined and, conversely, the effect of antimicrobial residues on the process as well. Finally, the life-cycle of different manure handling and processing methods, and their potential effects on nutrient recycling, energy production, antimicrobial residues and resistant bacteria were evaluated. Resistant and multi-resistant E. coli spread to the manure storages, although enrichment in their proportion over the manure chain was not detected. Only minor concentrations of antimicrobial residues were measured from the liquid manure. Instead, very high concentrations of antimicrobial residues were measured from the faeces, urine and milk of dairy cows medicated with antimicrobials, which may lead to high local concentrations in (dry) manures composed of them. In Finland, there is no withdrawal period for manure of medicated animals to be used as a fertilizer. Therefore, manures may contain antimicrobial residues, as well as resistant bacteria, which disseminate to the environment when applied to the fields. Animals and plants may be exposed to antimicrobial residues and resistant bacteria in agricultural and natural ecosystems in Finnish conditions as well. Therefore, fertilizer usage of faeces, urine and milk excreted by animals treated with antimicrobials should be subjected to critical assessment. Treating the manure with mesophilic anaerobic digestion may reduce the concentration of antimicrobial residues but does not necessarily destroy them. Furthermore, the process reduced the number of total E. coli bacteria, although it did not have an effect on the proportion of resistant E. coli. Along with energy production and nutrient recycling, different manure handling and processing methods may, however, be suitable for destroying and reducing antimicrobial residues and resistant bacteria from manure, and substantially reduce the emission of antimicrobial residues and resistant bacteria to the environment, as well as to the food chain. The aspect of tackling the spread of antimicrobial resistance is to be considered when manure processing methods are developed in Finland

Privacy-preserving 802.11 access-point discovery

It is usual for 802.11 WLAN clients to probe actively for access points in order to hasten AP discovery and to find "hidden" APs. These probes reveal the client's list of preferred networks, thus, present a privacy risk: an eavesdropper can infer attributes of the client based on its associations with networks. We propose an access-point discovery protocol that supports fast discovery and hidden networks while also preserving privacy. Our solution is incrementally deployable, efficient, requires only small modifications to current client and AP implementations, interoperates with current networks, and does not change the user experience. We note that our solution is faster than the standard hidden-network discovery protocol based on measurements on a prototype implementation. Copyright 2009 ACM

Comparison of Tests for Detection of β-Lactamase-Producing Staphylococci▿

Penicillin resistance identification tests are important in veterinary medicine. Six enzyme assays and a PCR test were compared for the detection of β-lactamase production or the β-lactamase gene in 175 staphylococcal isolates. We conclude that the PCR test and two nitrocefin-based assays can be recommended for routine clinical use