Resistance Monitoring Program Research Articles

P2.089 Antimicrobial Susceptibility Profile of Neisseria Gonorrhoeae Isolates in the Province of Québec: 2012

BackgroundSince 1988, the LSPQ (Laboratoire de santé publique du Québec) coordinates the Neisseria gonorrhoeae antimicrobial resistance programme,to support treatment guidelines updates. In the context of decreasing susceptibilities to 3rd generation...

Analysis of extended-spectrum- -lactamase-producing Escherichia coli isolates collected in the GERM-Vet monitoring programme

The aims of this study were (i) to detect extended-spectrum β-lactamase (ESBL) genes among 1378 Escherichia coli isolates from defined disease conditions of companion and farm animals and (ii) to determine the localization and organization of ESBL genes. E. coli isolates from the German resistance monitoring programme GERM-Vet were included in the study. Plasmids were transferred by conjugation or transformation and typed by PCR-based replicon typing. ESBL genes were detected by PCR; the complete ESBL genes and their flanking regions were sequenced by primer walking. Phylogenetic grouping and multilocus sequence typing (MLST) were performed for all ESBL-producing E. coli isolates. Of the 27 ESBL-producing E. coli isolates detected, 22 carried blaCTX-M-1 genes on IncN (n = 16), IncF (n = 3), IncI1 (n = 2) or multireplicon (n = 1) plasmids. A blaCTX-M-3 gene was located on an IncN plasmid and a blaCTX-M-15 gene was located on an IncF plasmid. A multireplicon plasmid and an IncHI1 plasmid harboured blaCTX-M-2. A blaTEM-52c gene was identified within Tn2 on an IncI1 plasmid. The blaCTX-M genes located within the same or related genetic contexts showed differences due to the integration of insertion sequences. Various MLST types were detected, with ST10 (n = 7), ST167 (n = 4) and ST100 (n = 3) being the most common. This study showed that the blaCTX-M-1 gene is the predominant ESBL gene among E. coli isolates from diseased animals in Germany and a considerable structural heterogeneity was found in the regions flanking the blaCTX-M-1 gene. Insertion sequences, transposons and recombination events are likely to be involved in alterations of the ESBL gene regions.

Pan-European resistance monitoring programmes encompassing food-borne bacteria and target pathogens of food-producing and companion animals

Antimicrobial resistance is a concern both for animal and human health. Veterinary programmes monitoring resistance of animal and zoonotic pathogens are therefore essential. Various European countries have implemented national surveillance programmes, particularly for zoonotic and commensal bacteria, and the European Food Safety Authority (EFSA) is compiling the data. However, harmonisation is identified as a weakness and an essential need in order to compare data across countries. Comparisons of resistance monitoring data among national programmes are hampered by differences between programmes, such as sampling and testing methodology, and different epidemiological cut-off values or clinical breakpoints. Moreover, only very few valid data are available regarding target pathogens both of farm and companion animals. The European Animal Health Study Centre (CEESA) attempts to fill these gaps. The resistance monitoring programmes of CEESA have been a collaboration of veterinary pharmaceutical companies for over a decade and include two different projects: the European Antimicrobial Susceptibility Surveillance in Animals (EASSA) programme, which collects food-borne bacteria at slaughter from healthy animals, and the pathogen programmes that collect first-intention target pathogens from acutely diseased animals. The latter comprises three subprogrammes: VetPath; MycoPath; and ComPath. All CEESA projects include uniform sample collection and bacterial identification to species level in various European Union (EU) member states. A central laboratory conducts quantitative susceptibility testing to antimicrobial agents either important in human medicine or commonly used in veterinary medicine. This ‘methodology harmonisation’ allows easy comparisons among EU member states and makes the CEESA programmes invaluable to address food safety and antibiotic efficacy.

Resistance to conventional insecticides in Pakistani populations of Musca domestica L. (Diptera: Muscidae): a potential ectoparasite of dairy animals

The house fly, Musca domestica L., is an important hygienic pest of humans and dairy animals with the potential to develop resistance to most chemical classes of insecticides. Six adult house fly strains from dairy farms in Punjab, Pakistan were evaluated for resistance to selected insecticides from organochlorine, organophosphate, carbamate and pyrethroid classes. For a chlorocyclodiene and two organophosphates tested, the resistance ratios (RR) at LC50 were in the range of 5.60-22.02 fold for endosulfan, 7.66-23.24 fold for profenofos and 2.47-7.44 fold for chlorpyrifos. For two pyrethroids and one carbamate, the RR values at LC50 were 30.22-70.02 for cypermethrin, 5.73-18.31 for deltamethrin, and 4.39-15.50 for methomyl. This is the first report of resistance to different classes of insecticides in Pakistani dairy populations of house flies. Regular insecticide resistance monitoring programs on dairy farms are needed to prevent field control failures. Moreover, integrated approaches including the judicious use of insecticides are needed to delay the development of insecticide resistance in house flies.

A survey of antimicrobial usage in animals in South Africa with specific reference to food animals

The purpose of this study was to set a benchmark for a monitoring and surveillance programme on the volumes of antimicrobials available and consumed by animals for the benefit of animal health in South Africa. This survey was collated from data available from 2002 to 2004. The authorised antimicrobials available in South Africa were firstly reviewed. The majority of available antimicrobials were registered under the Stock Remedies Act 36 1947. Secondly, volumes of antimicrobials consumed were then surveyed and it was found that the majority of consumed antimicrobials were from the macrolide and pleuromutilin classes, followed by the tetracycline class, the sulphonamide class and lastly the penicillin class.Results showed that 68.5% of the antimicrobials surveyed were administered as in-feed medications. 17.5% of the total volume of antimicrobials utilised were parenteral antimicrobials, whereas antimicrobials for water medication constituted 12% of the total and 'other' dosage forms, for example the topical and aural dosage forms, constituted 1.5% of the total. Intramammary antimicrobials represented 0.04% of the total. The surveillance systems for veterinary antimicrobials used by other countries were scrutinised and compared. It was concluded that a combination of the surveillance systems applied by Australia and the United Kingdom is the best model (with modifications) to apply to the animal health industry in South Africa. Such a surveillance system, of the volumes of veterinary antimicrobials consumed, should ideally be implemented in conjunction with a veterinary antimicrobial resistance surveillance and monitoring programme. This will generate meaningful data that will contribute to the rational administration of antimicrobials in order to preserve the efficacy of the existing antimicrobials in South Africa.

Sensitivity of Cercospora sojina isolates to quinone outside inhibitor fungicides

Frogeye leaf spot, caused by Cercospora sojina, causes yield reductions to soybean (Glycine max) grown worldwide. Quinone outside inhibitor (QoI) fungicides have been effective in managing frogeye leaf spot, but the risk of selecting C. sojina strains with resistance to this class of fungicides is considered high. A QoI fungicide resistance monitoring program was initiated, in which sensitivities to azoxystrobin, pyraclostrobin, and trifloxystrobin were determined in C. sojina isolates collected prior to QoI fungicide use on soybean (baseline group) and C. sojina isolates collected from soybean fields in 2007, 2008 and 2009. For the baseline group, the mean effective fungicide concentration at which 50% of the conidial germination was inhibited (EC50) was determined to be 0.01287, 0.00028 and 0.00116 μg ml−1 for azoxystrobin, pyraclostrobin and trifloxystrobin, respectively. When mean EC50 values of 2007, 2008 and 2009 C. sojina isolates were compared to baseline C. sojina EC50 values, a small but statistically significant (P ≤ 0.05) shift towards less sensitivity was observed for trifloxystrobin in 2009. Although small (<1.5-fold), this shift in sensitivity indicates a risk of selecting for C. sojina strains with reduced sensitivity to QoI fungicides, and fungicide sensitivities should continue to be monitored in the future.

Materials Educate Patients to Make Wise Choices on Tests and Procedures

appropriate, she said. “Antibiotics should be the last tool in the toolbox, starting with better farm practices,” Rogers said. “But the FDA doesn’t regulate farm practices.” Taylorexplainedthattheagencychose to pursue a voluntary phase-out over an outright ban because the agency felt it would require less time and fewer resources to work with industry groups than to pursue the legal course necessary to ban such antibiotic use. He emphasized that producers and industry groups have expressed willingness to make changes quickly. “We’d rather get to [a reduction in antibiotic use] over the next 2 years rather than litigate over the next 2 decades,” he said. Additionally, Taylor said, the agency hopes tominimize thepotentialnegative effect of these changes on the industries involved and on animal health by workingwithproducers,veterinarians,andindustry representatives. In particular, he acknowledgedthatcertainproducerswho havemore limitedaccess toveterinarians and other resources may have a difficult timecomplyingwithsomeofthechanges. “We know that change will be more challengingforsmall-scaleandgeographically remote producers,” he said. “We won’t forget about these special needs.” Ultimately, the success of this effort may be measured in 2 ways: by monitoring antibiotic resistance levels through the CDC’s National Antibiotic Resistance Monitoring Program and by tracking sales of these antibiotics, which are expected to decrease as use of these drugs for animal growth promotion decreases, according to the FDA. “If these guidelines do not bring down antibiotic use and drug-resistant bacteria, then the FDA will have to take additional steps,” Rogers said in a statement.

Baseline susceptibility to chlorantraniliprole of Brazilian populations of Plutella xylostella

Chlorantraniliprole, a new anthranilic diamide, is an insecticide that has recently been registered in Brazil to control several lepidopterans, including the diamondback moth, Plutella xylostella (L.). Chemical control of this pest has been particularly difficult because of its evolution of resistance to previous insecticide classes. To deploy a chlorantraniliprole resistance-monitoring program, the susceptibility of P. xylostella populations from different regions of Brazil was assessed using concentration-mortality bioassays before the commercial release of chlorantraniliprole. Mortality data were subjected to Probit analysis to estimate lethal parameters. Dosing by immersion or by spraying in a Potter tower were both suitable but topical application was not. All of the P. xylostella populations were highly susceptible to chlorantraniliprole (LC50 0.015–0.056 mg a.i./l of water) with those from the Northeast being the most tolerant. LC99 values were also low (0.065–0.281 mg a.i./l). The susceptibility variation among the populations was notably low, with the highest tolerance ratio being 3.8 fold, indicating a low variability of response among the Brazilian populations to this insecticide. A discriminating concentration of 0.3 mg a.i./l was obtained from the baseline data and proved to be effective for evaluating other populations, causing 100% mortality. The baseline data reflect the natural variation of these P. xylostella populations to chlorantraniliprole, rather than variations caused by previous exposure.

Pyraclostrobin sensitivity of baseline and fungicide exposed isolates of Pyrenophora tritici-repentis

Tan spot, caused by Pyrenophora tritici-repentis, is an important disease of wheat (Triticum aestivum L.) in the United States (U.S). Wheat growers sometimes rely on fungicide applications to manage foliar diseases. Pyraclostrobin is one of the recommended quinone outside inhibitor (QoI) fungicides and is commonly used to manage tan spot on wheat. Although P. tritici-repentis isolates has been reported as insensitive to QoI fungicides in Europe, little is known regarding the sensitivity of the P. tritici-repentis population to fungicides in the U.S. Twenty-eight isolates collected prior to 1997 and 136 isolates collected from pyraclostrobin treated fields in North Dakota were collected in 2007 and 2009 to determine if P. tritici-repentis isolates can use alternative respiration in the presence or absence of salicylhydroxamic acid (SHAM) in vitro and to determine the effective fungicide concentration that inhibited conidia germination by 50% (EC50). Six of 10 baseline isolates of P. tritici-repentis assayed had significantly higher (P ≤ 0.05) EC50 values when SHAM was not added to agar medium amended with pyraclostrobin, confirming that the fungus can utilize alternative respiration to overcome QoI toxicity in vitro. EC50 values of the baseline isolates ranged from 0.0012 to 0.0024 μg/ml (mean EC50 value of 0.0017 μg/ml and standard deviation is ±0.00039 μg/ml) while EC50 values of the 136 fungicide exposed isolates ranged from 0.0013 μg/ml to 0.0027 μg/ml (mean EC50 value of 0.0017 μg/ml and standard deviation is ±0.00030). These results indicate that the field exposed isolates have not shifted to reduced sensitivity to pyraclostrobin and that the baseline sensitivity values can be useful for a fungicide resistance monitoring program for P. tritici-repentis in the U.S.

欧米で実施されている薬剤耐性菌モニタリングシステムの現状

National Antimicrobial Resistance Monitoring ; NARMS, USA), Danish Integrated Antimicrobial Resistance Monitoring and Research Programme ; DANMAP, Denmark) and Swedish Veterinary Antimicrobial Resistance Monitoring ; SVARM, Sweden) were investigated.NARMS is a collaboration among the U. S. Food and Drug Administration (FDA), the U. S. Center for Disease Control and Prevention (CDC), U. S. Department of Agriculture (USDA). It monitors retail meat, human and food-producing animals. DANMAP is also an integrated system involving animals, retail meat and humans. Same as the National Veterinary Antimicrobial Resistance Monitoring System in Japan (JVARM), all systems monitor Salmonella spp., Campylobacter spp., Escherichia coli and Enterococcus spp.. In these systems, different from JVARM, they collect the animal samples in the slaughterhouse. In European countries, they emphasize to monitor the consumption of antimicrobials for food animals. In order to construct the better monitoring system, they often review the methods by themselves.

Porcine and Human Community Reservoirs ofEnterococcusfaecalis, Denmark

To the Editor: Enterococcus faecalis, which exists commensally in the gut in warm-blooded animals and humans, is an opportunistic pathogen that causes a variety of community-acquired and health care–associated infections, such as urinary tract and intraabdominal infections, bacteremia, and endocarditis (1). Only a few studies have assessed the relationships between clinical E. faecalis strains; strains endemic to the health care setting; and community strains residing in humans, animals, or animal-origin food (2). Recently we showed that the emergence of high-level gentamicin-resistant (HLGR) E. faecalis among patients with infective endocarditis (IE) coincided with an increase in HLGR E. faecalis in the pig population in Denmark (3). The majority of isolates belonged to the same clonal group (sequence type [ST] 16), suggesting that pigs constitute a community reservoir of HLGR E. faecalis. We investigated human and porcine community reservoirs of other E. faecalis clonal types associated with IE in humans in Denmark. A total of 20 consecutive gentamicin-susceptible E. faecalis isolates were obtained from IE patients in North Denmark Region during 1996–2002 (Table A1). Cases of IE were classified as definite (n = 12) or possible (n = 8) according to the modified Duke criteria (4). A case of community-acquired E. faecalis infection (n = 6) was defined in accordance with strict criteria applied for methicillin-resistant Staphylococcusaureus (5); otherwise, cases were deemed to be health care associated (n = 14) (Table A1). HLGR ST16 isolates recovered from 2 IE patients during the study period have been characterized (3) and were excluded from the present study. Using multilocus sequence typing (6), we identified 14 STs among the 20 IE isolates (Table A1), then compared them with STs from 2 collections of E. faecalis isolates collected as part of the Danish Integrated Antimicrobial Resistance Monitoring and Research Program (www.danmap.org): 1) all 14 isolates recovered from community-dwelling humans in North Denmark Region during 2002–2006 with approval from the local ethics committee ([KF] 01-006/02), which were classified into 10 STs in this study (Table A1); and 2) 19 pig isolates from 2001 that were shown in a previous study to belong to 12 STs (7). Among the 14 STs identified in IE isolates, 4 (ST19, ST21, ST72, and ST306) and 2 (ST40 and ST97) were also found among isolates from community-dwelling humans and pigs, respectively (Table A1). Isolates belonging to these 6 STs were further characterized by pulsed-field gel electrophoresis (PFGE) by using SmaI and grouped into PFGE pulsotypes as described (3). STs and PFGE pulsotypes (A–F) were largely concordant (ST97:A, ST72:B, ST19:C, ST40:D, ST21:E, and ST306:F), except for 2 isolates belonging to ST72 and ST40, for which PFGE banding patterns (U1 and U2, respectively) were unrelated to the major PFGE pulsotypes (A–F), and 1 ST306 isolate exhibiting the ST21-like PFGE banding pattern E (Table A1). These findings confirm the genetic relatedness of IE isolates with those from community-dwelling humans (ST72:B, ST19:C, ST21:E, and ST306:F) and pigs (ST97:A and ST40:D). Seven (64%) of 11 IE isolates belonging to these 6 clonal types originated from IE patients with health care–associated risk factors (Table A1), which suggests that health care users are predisposed to colonization and infection with E. faecalis strains residing in human and porcine community reservoirs. Previous reports have shown that epidemiologically distinct E. faecalis populations differ in terms of biofilm formation, virulence gene content, and antimicrobial drug susceptibility profiles (2,8). Therefore, we characterized all isolates with respect to these traits. Isolates were categorized into strong, medium, weak, and nonbiofilm formers by using the method of Mohamed et al. (8). The presence of 12 virulence-associated and pathogenicity island genes (ebpA, gelE, ef1824, hylA, ef1896, ef2347, ef2505, hylB, ace, cbh, esp, and ef0571) was investigated by using colony lysates and probes that have been described elsewhere (9). The antimicrobial drug susceptibility profiles (ampicillin, chloramphenicol, ciprofloxacin, erythromycin, gentamicin, kanamycin, linezolid, penicillin, streptomycin, teicoplanin, tetracycline, and vancomycin) were determined by the Sensititre system (Trek Diagnostic Systems, East Grinstead, UK) in accordance with Clinical and Laboratory Standards Institute guidelines (10). The isolates were generally homogenous within each clonal type in terms of biofilm formation, presence of virulence-associated and pathogenicity island genes, and resistance profiles (Table A1), further supporting that IE isolates are genetically related to those from community-dwelling humans and pigs, respectively. Notably, most IE isolates were susceptible to ampicillin (100%), penicillin (100%), vancomycin (100%), high-level gentamicin (100%), and high-level streptomycin (80%), which are the drugs of choice in therapeutic regiments for E. faecalis endocarditis. In conclusion, our results suggest that the normal intestinal microflora of humans and pigs are community reservoirs of clinical E. faecalis and link 2 porcine-origin clonal types of gentamicin-susceptible E. faecalis, ST97:A, and ST40:D to IE in humans in Denmark. This finding strengthens existing evidence that pigs can be a source of serious infections in humans.

Life Stage Toxicity and Residual Activity of Insecticides to Codling Moth and Oriental Fruit Moth (Lepidoptera: Tortricidae)

The codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck), are two key pests of apple (Malus domestica Borkh.) in North Carolina. Growers extensively relied on organophosphate insecticides, primarily azinphosmethyl, for > 40 yr to manage these pests. Because of organophosphate resistance development and regulatory actions, growers are transitioning to management programs that use new, reduced-risk, and OP-replacement insecticides. This study evaluated the toxicity of a diversity of replacement insecticides to eggs, larvae, and adults, as well as an assessment of their residual activity, to codling moth and oriental fruit moth. Laboratory-susceptible strains of both species were used for all bioassays. Fresh field-harvested apples were used as a media for assessing the ovicidal activity of insecticides. For larval studies, insecticides were topically applied to the surface of lima bean-based diet, onto which neonates were placed. Toxicity was based on two measures of mortality; 5-d mortality and development to adult stage. Ovicidal bioassays showed that oriental fruit moth eggs were generally more tolerant than codling moth eggs to insecticides, with novaluron, acetamiprid, and azinphoshmethyl having the highest levels of toxicity to eggs of both species. In contrast, codling moth larvae generally were more tolerant than oriental fruit moth to most insecticides. Methoxyfenozide and pyriproxyfen were the only insecticides with lower LC50 values against codling moth than oriental fruit moth neonates. Moreover, a number of insecticides, particularly the IGRs methoxyfenozide and novaluron, the anthranilic diamide chlorantriliprole, and the spinosyn spinetoram, provided equal or longer residual activity against codling moth compared with azinphosmethyl in field studies. Results are discussed in relation to their use in devising field use patterns of insecticides and for insecticide resistance monitoring programs.

First isolation of ESBL-producing Salmonella and emergence of multiresistant Salmonella Kentucky in turkey in Poland

The first CTX-M-producing Salmonella was described in primary animal production in Poland, due to the antimicrobial resistance monitoring and control program introduced in turkeys. It was associated with the outbreak of multiresistant Salmonella Kentucky in non-diseased turkeys, foods and food production environment, but found also in municipal sewage sludge. The emergence along the food chain of clonally related strains resistant to critically important antimicrobial agents, including cephalosporins, quinolones, sulfonamides, aminoglycosides, phenicols, and tetracycline, which are used against foodborne pathogens, poses a serious public health threat.

Comparative assessment of the field-susceptibility of Sesamia nonagrioides to the Cry1Ab toxin in areas with different adoption rates of Bt maize and in Bt-free areas

A three year (2003–2005) field study compared the susceptibility to the Cry1Ab toxin, expressed in Bt maize, of Mediterranean corn borer (MCB) Sesamia nonagrioides populations collected from areas with different adoption rates of Bt maize in Spain with Bt-free areas in Greece. Spain is the only European country where the cultivar Compa CB derived from the event Bt176 was commercially grown, from 1998 to 2005. The large decrease of the titer of the toxin in this cultivar at later growth stages represented the worst-case scenario for resistance development of MCB, since larvae of the second and third generations were exposed to sublethal concentrations of Cry1Ab toxin. Our data revealed that the variation in susceptibility to Cry1Ab for the MCB Spanish field populations analyzed in the three years was very low, with LC 50 values fluctuating between 12 and 30 ng Cry1Ab/cm 2, regardless of the region of origin, the type of maize (Bt or non-Bt) and the year. Furthermore, no significant differences were found when comparisons were made with a laboratory population (LC 50 values: 18–26 ng Cry1Ab/cm 2) or with field populations from Greece (Bt-free areas), which displayed LC 50 values ranging between 22 and 27 ng Cry1Ab/cm 2. Standardizing bioassay protocols proved to be essential for obtaining comparable results. These findings suggest that resistant MCB populations did not evolve in those Spanish maize areas where Compa CB was largely cultivated for eight years, contradicting the expected rapid development of resistance under these unfavourable conditions. Additionally, our results can be used as baseline indices in post-market resistance monitoring programs if Bt maize is introduced in Greece. Further studies should continue, since the insights gained from a resistance monitoring program may help to enhance the durability of Bt maize.

Harmonisation of resistance monitoring programmes in veterinary medicine: an urgent need in the EU?

Antimicrobial surveillance systems in Denmark (DANMAP), The Netherlands (MARAN), Spain (VAV) and Sweden (SVARM) as well as the European Antimicrobial Susceptibility Surveillance in Animals (EASSA) were reviewed. Data have been considered for extended-spectrum cephalosporins, fluoroquinolones and macrolides against food-borne and commensal bacteria. The greatest challenge arises from the lack of agreement between programmes on what is meant by resistance through the use of different interpretive criteria. Indeed, it is shown here that the extent of the differences depends on the antibacterial compound being investigated, the methodology and the interpretive criteria used. This emphasises a need to agree a definition for resistance and for epidemiological cut-off values and to consider harmonising the antimicrobials used in surveillance. This analysis of the data highlights the usefulness of using both epidemiological cut-off values and clinical resistance breakpoints for the purpose of detection of decreased susceptibility and development of clinical resistance, respectively. It is concluded that harmonisation in resistance monitoring programmes is needed since there is potential for data to be appropriately used within risk analysis, providing the opportunity to implement appropriate risk management steps as a response to the public health issues arising from changes in antibiotic resistance in food-borne pathogens and commensal organisms.

Baseline Sensitivity of Cercospora zeae-maydis to Quinone Outside Inhibitor Fungicides.

Cercospora zeae-maydis, the causal agent of gray leaf spot on corn (Zea mays), can cause severe yield loss in the United States. Quinone outside inhibitor (QoI) fungicides are effective tools that can be used to manage gray leaf spot, and their use has increased in corn production in the United States. In total, 61 C. zeae-maydis isolates collected from fields in which QoI fungicides had never been applied were tested in vitro using azoxystrobin-, pyraclostrobin-, or trifloxystrobin-amended medium to determine the effective fungicide concentration at which 50% of the conidial germination was inhibited (EC50). The effect of salicylhydroxamic acid (SHAM) also was evaluated for seven isolates to determine whether C. zeae-maydis is capable of using alternative respiration in azoxystrobin-amended medium. All seven C. zeae-maydis isolates tested had significantly greater (P < 0.02) EC50 values when SHAM was not included in medium amended with azoxystrobin, indicating that C. zeae-maydis has the potential to utilize alternative respiration to overcome QoI fungicide inhibition in vitro. Baseline EC50 values of azoxystrobin ranged from 0.003 to 0.031 μg/ml, with mean and median values of 0.018 and 0.019 μg/ml, respectively. Baseline EC50 values of pyraclostrobin ranged from 0.0003 to 0.0025 μg/ml, with mean and median values of 0.0010 and 0.0010 μg/ml, respectively. Baseline EC50 values of trifloxystrobin ranged from 0.0004 to 0.0034 μg/ml, with mean and median values of 0.0023 and 0.0024 μg/ml, respectively. These baseline sensitivity values will be used in a fungicide resistance monitoring program to determine whether shifts in sensitivity to QoI fungicides are occurring in C. zeae-maydis populations.

Antimicrobial resistance of thermotolerant Campylobacter spp. as a food safety issue

Antimicrobial resistance is a daunting public health threat impacting both human and animal health and it is a cause for concern wherever antimicrobial agents are in use. The usage of antimicrobial drugs in food producing animals could results in significant food safety issue - antimicrobial resistance among zoonotic bacteria in these animals. Resistance monitoring program still does not exist in Serbia, so we made a pilot program to screen the situation in our abattoirs. We found similar situation like the one in EU. The resistance to one or more antimicrobial drugs was found in 40.00% and 75.32% Campylobacter spp. strains isolated from poultry and pig carcasses, respectively. Fluoroquinolones are anitmicrobial drugs which, beside beta-lactams, are most often used in poultry breeding. Fluoroquinolones are also very important for treatment of some human diseases. We examined relationship between presence of fluoroquinolone resistant C. jejuni in poultry carcasses and fluoroquinolone treatment of poultry. Treatment with one of this antimicrobials - enrofloxacine selects resistant strains in chickens carcasses, C. jejuni strains resistant to enrofloxacine were isolated from all livers (100%) and 70% carcasses. The resistant bacteria may then be transmitted to humans through food supply and increase the risk of treatment failures. Resistant zoonotic pathogens in food have to be controlled through a complete, continuous farm-to-fork system.

Large-scale monitoring of imidacloprid susceptibility in the cat flea, Ctenocephalides felis

Although on-animal topical treatment with compounds such as imidacloprid has revolutionized the control of the cat flea, Ctenocephalides felis (Bouché) (Siphonaptera: Pulicidae), the development of insecticide resistance is a continuing threat. As part of a highly co-ordinated and unprecedented resistance monitoring programme for C. felis, 1437 flea isolates were collected by veterinary clinics in Australia, Germany, France, the U.K. and 29 states in the U.S.A. from 2002 to 2009. About 65% of the collections were made from June to October each year and 71% of the collections were from cats. Collections of flea eggs were sent to one of five different laboratories, where they were tested with a diagnostic dose of imidacloprid (3 p.p.m.) applied to larval flea-rearing medium. Of the 1437 collections received, 1064 contained adequate numbers of eggs for testing. Of these isolates, untreated eggs failed to hatch in 22.7% and were not considered valid bioassays. Survival rates >5% and development of adult fleas (a threshold for further testing) occurred in only 22 isolates. They were re-tested with the same diagnostic dose and none produced >5% adult emergence. Complete dose-response bioassays were performed on three of the isolates that had triggered a second test and produced slopes, intercepts and LC(50) values similar to those for existing susceptible laboratory strains. Results confirmed sustained susceptibility of C. felis to imidacloprid, despite its widespread use for over a decade.

Statement on the assessment of the safety of Cylactin® (Enterococcus faecium) used in animal nutrition

EFSA JournalVolume 8, Issue 12 1955 StatementOpen Access Statement on the assessment of the safety of Cylactin® (Enterococcus faecium) used in animal nutrition EFSA Panel on Additives and Products or Substances Used in Animal Feed (FEEDAP), EFSA Panel on Additives and Products or Substances Used in Animal Feed (FEEDAP)Search for more papers by this author EFSA Panel on Additives and Products or Substances Used in Animal Feed (FEEDAP), EFSA Panel on Additives and Products or Substances Used in Animal Feed (FEEDAP)Search for more papers by this author First published: 21 December 2010 https://doi.org/10.2903/j.efsa.2010.1955Citations: 5 Panel members: Gabriele Aquilina, Georges Bories, Paul Brantom, Andrew Chesson, Pier Sandro Cocconcelli, Joop de Knecht, Noël Albert Dierick, Mikolaj Antoni Gralak, Jürgen Gropp, Ingrid Halle, Reinhard Kroker, Lubomir Leng, Anne-Katrine Lundebye Haldorsen, Alberto Mantovani, Miklós Mézes, Derek Renshaw and Maria Saarela Correspondence: feedap@efsa.europa.eu Acknowledgement: The Panel wishes to thank the members of the Working Group on Microorganisms, including Roland Leclercq, Atte von Wright and Guido Rychen, for the preparatory work on this scientific opinion for the support provided to this scientific opinion. Adoption date: 7 December 2010 Published date: 21 December 2010 Question number: EFSA-Q-2010-01264 On request from: European Commission AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References Bismuth R and P. Courvalin, 2009. Aminoglycosides and Gram-positive bacteria. In: Antibiogram. Eds P. Courvalin, R. Leclercq, L. Rice. 2009, ASM Press, pp. 213– 224. Costa, Y., Galimand, M., Leclercq, R., Duval, J., and Courvalin, P. 1993. Characterization of the chromosomal aac(6′)-Ii gene specific for Enterococcus faecium. Antimicrobial Agents and Chemotherapy, 37, 1896– 1903. DANMAP (Danish Integrated Antimicrobial resistance Monitoring and Research Programme), 2009, online. Use of antimicrobial agents and occurrence of antimicrobial resistance in bacteria from food animals, foods and humans in Denmark. Available from www.danmap.org. EC (European Commission), 2001, updated 2003, online. Opinion of the Scientific Committee on Animal Nutrition on the criteria for assessing the safety of micro-organisms resistant to antibiotics of human clinical and veterinary importance. Available from europa.eu.int/comm/food/fs/sc/scan/out108_en.pdf. EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), 2005. Scientific Opinion on the updating of the criteria used in the assessment of bacteria for resistance to antibiotics of human and veterinary importance. The EFSA Journal, 223. EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), 2008a. Technical guidance - Update of the criteria used in the assessment of bacterial resistance to antibiotics of human or veterinary importance. The EFSA Journal, 732, 1– 15. EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), 2008b. Guidance for the preparation of dossiers for zootechnical additives. The EFSA Journal, 776, 1– 17. EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), 2010. Scientific Opinion on the safety and efficacy of Cylactin® (Enterococcus faecium) for chickens for fattening. EFSA Journal, 8(7): 1661. [13 pp.]. Galimand M., Schmitt E., Panvert M., Douthwaite S., Mechulam Y. and Courvalin P., 2010, in press. Intrinsic resistance to aminoglycosides in Enterococcus faecium is conferred by the 16S rRNA m5C1404-specific methyltransferase EfmM. RNA. Moellering R.C. Jr., Korzeniowski O.M., Sande M.A. and Wennersten C.B., 1979. Species-specific resistance to antimicrobial synergism in Streptococcus faecium and Streptococcus faecalis. Journal of Infectious Diseases, 140, 203– 208. Citing Literature Volume8, Issue12December 20101955 ReferencesRelatedInformation

Differential efficacy of three commonly used pyrethroids against laboratory and field‐collected larvae and adults of Helicoverpa zea (Lepidoptera: Noctuidae) and significance for pyrethroid resistance management

Helicoverpa zea (Boddie) pyrethroid resistance monitoring programs typically utilize cypermethrin in the adult vial test. Here we investigated if differences in insect growth stage and pyrethroid structure affect resistance ratios and discuss implications for pyrethroid resistance management. Vial bioassays with cypermethrin, esfenvalerate and bifenthrin were conducted on H. zea third instars and male moths from a susceptible laboratory colony and the F1 generation of a pyrethroid-resistant field population. In the susceptible population, both growth stages were most sensitive to bifenthrin and adults were more sensitive to esfenvalerate than cypermethrin. LC(50) resistance ratios for the larvae and adults of the resistant population were approximately two times higher for bifenthrin than cypermethrin or esfenvalerate. For the resistant population, vial assays using either growth stage gave similar resistance ratios for each of the three pyrethroids, respectively, proving the adult vial test accurately reflects larval resistance. However, as resistance ratios varied considerably depending on the pyrethroid used, resistance ratio values obtained with one pyrethroid may not be predictive of resistance ratios for other pyrethroids. Our results suggest that carefully chosen pyrethroid structures diagnostic for specific mechanisms of resistance could improve regional monitoring programs.