Prevalence, antibiotic resistance and molecular characterisation of Staphylococcus aureus in pigs at agricultural fairs in the USA

Fairs and petting zoos have been associated with outbreaks of zoonotic disease. Previously, the presence of meticillin-resistant Staphylococcus aureus (MRSA) was documented in commercial pigs; therefore, it was hypothesised that antibiotic-resistant S aureus may also occur in pigs exhibited at agricultural fairs. To test this hypothesis, 157 pigs were swabbed at two state fairs in 2008 to 2009. Both nares were sampled and cultures were grown in enrichment broth, then plated onto selective MRSA plates and blood plates. S aureus was confirmed using phenotypic and molecular methods, and was analysed using spa typing, gene-specific polymerase chain reaction and antibiotic susceptibility testing. The presence of S aureus was confirmed in samples collected from pigs exhibited at USA pig shows. Twenty-five of 157 (15.9 per cent) samples were positive for S aureus. Two isolates (8 per cent) were resistant to meticillin; 23/25 (92 per cent), 14/25 (56 per cent) and 15/25 (60 per cent) were resistant to tetracycline, erythromycin and clindamycin, respectively. spa typing revealed multiple isolates of spa type t034 (9/25, 36 per cent) and t337 (7/25, 28 per cent) and singletons of t002, t209, t526, t1236, t1334, t1683, t3075, t5784 and t5883. These results verify the presence of antibiotic-resistant S aureus in pigs exhibited at USA fairs, suggesting that pigs are a potential reservoir for S aureus within this environment.     

In situ volatile collection, analysis, and comparison of three Centaurea species and their relationship to biocontrol with herbivorous insects

Centaurea solstitialis, commonly known as yellow starthistle, is an invasive plant listed as a noxious weed in the western areas of North America and is the target of classical biological control, which involves release of herbivores known to be specific to this plant. These insects often choose their host plant on the basis of the volatile organic compounds (VOCs) emitted. Accordingly, volatile analysis of host plants can provide insight into VOCs that may attract and/or repel the insect. To this end, solid-phase microextraction (SPME) and a customized collection bag were utilized to perform in situ volatile collection on intact and mechanically damaged leaves of Centaurea solstitialis, Centaurea cyanus, and Centaurea cineraria. Volatile identification was performed by GC-MS, and the VOC differences were determined. The plants C. solstitialis and C. cyanus have been reported to attract the weevil, Ceratapion basicorne, a candidate for biological control, whereas C. cineraria does not attract the weevil. Major VOCs unique to C. cineraria include the sesquiterpenes cyclosativene, alpha-ylangene, and trans-alpha-bergamotene. The compound trans-beta-farnesene was unique to C. solstitialis and C. cyanus.     

Evaluation of a multi‐agent chemotherapy protocol combining dexamethasone,melphalan, actinomycin D,and cytarabine for the treatment of resistant canine non‐Hodgkin high‐grade lymphomas: a single centre's experience

The DMAC protocol (dexamethasone, melphalan, actinomycin‐D, cytarabine) has been evaluated in American studies for the treatment of relapsed canine lymphoma, comparing similarly to other rescue protocols. The aim of this study was to evaluate efficacy and toxicity of DMAC, in a larger UK cohort of resistant canine lymphomas. Medical records of dogs with resistant non‐Hodgkin high‐grade lymphomas that received DMAC as a rescue protocol were reviewed from 2007 to 2017. Response, time from initiation to discontinuation (TTD) and toxicity (Veterinary Cooperative Oncology Group criteria) were assessed. One hundred dogs were included; 86 received CEOP (modified CHOP including epirubicin) as first‐line treatment. Thirty‐five dogs (35%) responded: 21 complete responders (CRs) and 14 partial responders (PRs). Responders had significantly longer TTD (P < 0.001) compared with non‐responders: 62 days (range 28‐952) for CR vs 32 days (range 20‐70) for PR. Six CR received more than six cycles of DMAC (range 7‐36 cycles) and experienced a longer TTD (median 508, range 126‐952 days). Thrombocytopenia occurred in 45% (24 grade 1‐2, 21 grade 3‐4) and neutropenia in 36% of cases (29 grade 1‐2, 7 grade 3‐4). Gastrointestinal toxicity occurred in 42% of dogs (40 grade 1‐2, 2 grade 3‐4). Owing to chemotherapy toxicity, treatment was discontinued in five, and hospitalization required in six cases. In this study, response to DMAC was lower and of generally shorter duration than previously reported. Toxicity was high, but infrequently led to hospitalization or discontinuation of treatment.     

Evaluation of a multi‐agent chemotherapy protocol combining lomustine,procarbazine and prednisolone (LPP) for the treatment of relapsed canine non‐Hodgkin high‐grade lymphomas

The standard of care treatment for canine lymphoma is multi‐agent chemotherapy containing prednisolone, cyclophosphamide, vincristine and an anthracycline such as doxorubicin (CHOP) or epirubicin (CEOP). Lomustine, vincristine, procarbazine, and prednisone (LOPP) has been evaluated as a rescue, with encouraging results; however, resistance to vincristine is likely in patients relapsing on CHOP/CEOP, and this agent may enhance LOPP toxicity without improving efficacy. The aim of this study was to evaluate responses to a modified‐LOPP protocol that does not include vincristine (LPP) and is administered on a 21‐day cycle. Medical records of dogs with high‐grade multicentric lymphoma from 2012 to 2017 were reviewed. Dogs with relapsed lymphoma that received LPP as a rescue protocol were enrolled. Response, time from initiation to discontinuation (TTD) and toxicity of LPP were assessed. Forty‐one dogs were included. Twenty‐five dogs (61%) responded to LPP including 12 complete responses (CR) and 13 partial responses (PR). Responders had a significantly longer TTD (P < .001) compared to non‐responders with 84 days for CR and 58 days for PR. Neutropenia was documented in 20 dogs (57%): 12 grade I to II, 8 grade III to IV. Thrombocytopenia was infrequent (20%): 5 grade I to II, 2 grade III to IV. Twelve dogs developed gastrointestinal toxicity (30%): 10 grade I to II and 2 grade III. Nineteen dogs had elevated ALT (59%): 9 grade I to II, 10 grade III to IV. Treatment was discontinued due to toxicity in 8 dogs (19%). The LPP protocol shows acceptable efficacy and toxicity‐profile and minimizes in‐hospital procedures.     

Three-dimensional deformation measured in an alaskan glacier

Measurements of movement along 28 boreholes reveal the three-dimensional flow field in a 6 million cubic meter reach of Worthington Glacier, a temperate valley glacier located in Alaska. Sliding at the bed accounted for 60 to 70 percent of the glacier's surface motion. Strain rates in the ice were low from the surface to a depth of about 120 meters, but then increased rapidly toward the bed. Ice deformation was not affected by temporal changes in the sliding rate. The three-dimensional pattern of motion indicates that plane strain, which is often assumed by models, is a poor approximation of this viscous flow.     

Ubiquitin gene expression and ubiquitin conjugation in chicken muscle do not reflect differences in growth rate between broiler and layer birds.

Previous work has shown that chicken strains selected for growth (broilers) degrade muscle proteins less rapidly than those selected for egg laying. They also have decreased calpain and increased calpastatin content in breast muscle. This study aimed to test the hypothesis that these differences correlate with changes in the ATP- and ubiquitin-dependent proteolytic system. Chickens of a broiler strain (Ross 1) and a layer strain (ISABrown) were reared to the age of 4 wk under identical conditions with ad libitum access to feed and water. Mean fractional growth rates were 10.4%/d for broilers and 7.4%/d for layers. Feed intake measured in the last week of the trial was slightly greater in layer birds (.11 and .12 g x g body weight(-1) x d(-1) for broilers and layers respectively; P < .006). Polyubiquitin (UbI) messenger RNA was abundant in the muscles of these well-fed birds, but it showed little difference between strains. Muscle did not significantly express the UbII polyubiquitin gene. The ATP-dependent system conjugating ubiquitin to endogenous proteins had greatest activity in the gastrocnemius muscle of broiler birds but was not significantly different between breeds. Proteins cross-reactive with antisera to recombinant human proteasome regulatory subunits MSS1 (multicopy suppressor of SUG 1; S7) and TBP1 (tat binding protein 1; S6') were present in muscle homogenates from both strains of bird. The chick equivalent of TBP1 was more abundant in breast muscle of broiler birds than in leg muscle, or in either muscle of layers. Antiserum to recombinant yeast subunit mts2 (mitosis temperature sensitive gene 2; S4) did not react with any protein of the expected size but detected a 30-kDa peptide that was not associated with the 26S proteasome; this was found only in muscle from the layer strain. Hence, during normal growth of chickens, rates of protein degradation are not controlled by the expression of ubiquitin mRNA or the conjugation of ubiquitin. However, the composition of the 26S proteasome may be a regulatory factor.     

Status,ecology and conservation of an endemic fish,Oreochromis niloticus baringoensis,in Lake Baringo,Kenya

• 1. The tilapia Oreochromis niloticus baringoensis is a genetically and morphologically distinct sub‐species of Oreochromis niloticus endemic to Lake Baringo, Kenya. In recent years, concern has been expressed as to its status. Recent declines in catch returns suggest the population may be threatened, with conservation action required to safeguard it.
• 2. Catch returns from the Baringo fishery since 1964 have shown considerable fluctuations for all species, but especially O. n. baringoensis. From a peak of 712 t in 1970, their total catch was only 5 t in 2005, despite a 2 year period of closure in 2002 and 2003. Changes in fishery catch and relative abundance were independent of exploitation in the fishery but were significantly correlated with lake level.
• 3. Few individuals were captured at lengths >250 mm, with no fish sampled >284 mm. During periods of high lake level, individuals matured at smaller sizes and were capable of growing to larger ultimate sizes. With maturity at lengths <130 mm and fishery regulations preventing removal of fish <180 mm, there was a relatively large proportion of mature fish that was below exploitation size each year (19 to 44%). In most years, the proportion of fish available for exploitation was <10%.
• 4. Stable isotope analyses revealed O. n. baringoensis was reliant upon planktonic basal resources and zooplankton carbon. There was only minimal trophic overlap with other fish species in the lake, indicating little potential for competition for food resources.
• 5. These data suggest that the population status of O. n. baringoensis is not threatened per se, but subject to an unpredictable and unstable environment that strongly influences their life‐history traits and, ultimately, their population abundance, and should be managed accordingly.

Copyright © 2008 John Wiley & Sons, Ltd.     

Lethal concentration of Cymbopogon citratus (Poaceae) essential oil for Dolops discoidalis and Argulus sp. (Crustacea: Argulidae)

This study investigated the acute toxicity (LC_50-24 hr) effects of the essential oil of Cymbopogon citratus for adult Argulus sp. and Dolops discoidalis, before and during oviposition. In vitro acute toxicity (LC_50-24 hr) was tested using 20, 40, 60, 80, 100, 120, 140 and 160 μg/L of C. citratus essential oil, and two control groups (one with cultivation tank water and one with cultivation tank water + alcohol) were used. Specimens of Argulus sp. and D. discoidalis submitted to acute toxicity were evaluated using histological procedures. The major chemical compounds of C. citratus essential oil were geranial (47.5%), neral (35.6%) and myrcene (6.7%). The LC_50-24 hr for Argulus sp. adults was 67.97 μg/L, while for D. discoidalis it was 59.55 µg/L. In the oviposition of both species of argulids, maximum mortality began with treatments of 140 μg/L, while the LC_50-24 hr for Argulus sp. and D. discoidalis was 83.98 μg/L and 82.48 μg/L, respectively. In both argulid species exposed to C. citratus essential oil, morphological alterations were observed only in the eyes, and they occurred in the ommatidium and rhabdomeres and were dependent on the concentration of C. citratus essential oil and the parasite species.     

The potential of integrated marketing in increasing adoption of land rehabilitation practices in northwest New South Wales,Australia

Land degradation is a major threat to the productivity of agricultural land in Australia, and on the soils used for growing wheat (Triticum aestivum) soil erosion and fertility decline are serious problems. A study financed jointly by NSW Agriculture, Grains Research and Development Corporation (GRDC) and agribusiness looked at the effectiveness of using integrated marketing to increase adoption of dryland lucerne (Medicago sativa) in rotations in northwestern NSW as a means to rehabilitate degraded wheat soils. At the time of the study, average wheat and protein yields were declining. Integrated marketing, with heavy reliance on television advertising, was run during Summer 1992 and Autumn 1993. Approximately 750 wheat growers, located around Moree in NSW comprised the target group. A similar number of comparable farmers from around Dalby in southern Queensland, who were not exposed to the promotional campaign, formed the control group. Farmers were surveyed by mail just before and 18 months after the campaign. While the results were compounded by severe drought during the study time, as well as by other constraints, the data suggest none the less the value of this approach in getting farmers to change their practices. One in six wheat growers in the target area were aware of the free information kit available via the advertised 1800 number or freepost mail coupon; one in twelve obtained the kit. Television was the most influential media in eliciting a response, followed by the Australian Grain Magazine. The results suggested that the campaign did in fact engender the desired change. The study highlights the possible role integrated marketing may play in rural Australia, whether the subject dealt with is agricultural, environmental or other, not because of any novelty value, but because of the technique itself. © 1998 John Wiley & Sons, Ltd.