Inhibition of virulence gene expression in Staphylococcus aureus by novel depsipeptides from a marine photobacterium

During a global research expedition, more than five hundred marine bacterial strains capable of inhibiting the growth of pathogenic bacteria were collected. The purpose of the present study was to determine if these marine bacteria are also a source of compounds that interfere with the agr quorum sensing system that controls virulence gene expression in Staphylococcus aureus. Using a gene reporter fusion bioassay, we recorded agr interference as enhanced expression of spa, encoding Protein A, concomitantly with reduced expression of hla, encoding α-hemolysin, and rnaIII encoding RNAIII, the effector molecule of agr. A marine Photobacterium produced compounds interfering with agr in S. aureus strain 8325-4, and bioassay-guided fractionation of crude extracts led to the isolation of two novel cyclodepsipeptides, designated solonamide A and B. Northern blot analysis confirmed the agr interfering activity of pure solonamides in both S. aureus strain 8325-4 and the highly virulent, community-acquired strain USA300 (CA-MRSA). To our knowledge, this is the first report of inhibitors of the agr system by a marine bacterium.     

Evaluation of a Burdizzo Castrator for Neutering of Dogs

A Burdizzo castrator was evaluated for the neutering of dogs. Histological and morphological changes of spermatic cells and peripheral serum testosterone after challenge with a GnRH-analogue (gonadorelin) were assessed. There was a control group (G1), a surgically castrated group (G2) and a Burdizzo group (G3) divided in two, G3a receiving two crunches in each spermatic cord and G3b receiving one crunch in each spermatic cord. Sixteen days after application of the Burdizzo blood samples were taken from the dogs at 30 min interval during 2 h; after the second sample the dogs were treated with 1 mug/kg body weight of gonadorelin i.v. The same protocol of gonadorelin challenge was performed in G1 and G2 dogs. The G2 dogs were surgically castrated after the second blood sample, before the gonadorelin treatment, and the G1 dogs after the last blood sample. The excised gonads were examined histologically, and sperm smears were prepared from the caudae epididymidis. The testes and plexus pampiniformis of the G1 and G2 dogs had a normal histological appearance, and they had morphologically normal epididymal sperm cells. In all G3 dogs, there was an acute fibrosis with an inflammatory reaction in the plexus pampiniformis. The testes from the G3a dogs showed diffuse areas of infarction and degeneration of the parenchyma. Similar but less diffuse lesions were seen in group 3b dogs. The deferent ducts from all G3 dogs showed vasitis and/or sperm granulomas. Azoospermia or sperm malformations were observed in the epididymal smears from the G3 dogs. Testosterone concentration in the G1 dogs increased after gonadorelin application (p < 0.0001). The G2 dogs had basal testosterone levels after castration (p < 0.001) and did not respond to gonadorelin. Groups 3a and b showed a slight but non-significant increase in testosterone concentration after gonadorelin challenge, supposedly due to the reduction of testicular blood flow and loss of testicular interstitial tissue.     

Fusarium wilt of common heliotrope (heliotropium europaeum)

Occurrence of Fusarium wilt of common heliotrope(Heliotropium europaeum L.) is reported. Pathogenicity of the causal agent was confirmed by reisolation from inoculated heliotrope plants. The specificity of the isolate was shown by cross-inoculation tests with five formae speciales and by inoculating the five respective hosts with a monoconidial isolate of the present fungus. Only the latter fungus was found to incite wilt in common heliotrope; the proposed name of this forma specialis isFusarium oxysporum f. sp.heliotropae nov. f.     

Behandlung von Reis mit Neem und Diatomeenerde zur Bekämpfung der vorratsschädlichen Coleopteren Sitophilus oryzae und Tribolium castaneum

The commercial available diatomaceous earth Fossil Shield® and the neem product Neem Azal-T/S® are tested as single treatments and in combination as controls for the stored product pests Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). The diatomaceous earth, applied in concentrations of 0.5 g, 1 g and 2 g kg^-1 rice, reduced numbers of surviving beetles significantly (over a period of 3 weeks). A single treatment with the neem product, in concentrations of 0.01 g, 0.1 g, 0.2 g and 1 g azadirachtin kg^-1 rice, increased the mortality rate for both species significantly. The combination of neem and diatomaceous earth (1 g diatomaceous earth with 0.2 g or 1 g azadirachtin kg^-1 rice) was more effective than the single treatment in reducing numbers of surviving beetles.     

Behandlung von Reis mit Neem und Diatomeenerde zur Bek?mpfung der vorratssch?dlichen Coleopteren Sitophilus oryzae und Tribolium castaneum

The commercial available diatomaceous earth Fossil Shield® and the neem product Neem Azal-T/S® are tested as single treatments and in combination as controls for the stored product pests Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). The diatomaceous earth, applied in concentrations of 0.5 g, 1 g and 2 g kg^-1 rice, reduced numbers of surviving beetles significantly (over a period of 3 weeks). A single treatment with the neem product, in concentrations of 0.01 g, 0.1 g, 0.2 g and 1 g azadirachtin kg^-1 rice, increased the mortality rate for both species significantly. The combination of neem and diatomaceous earth (1 g diatomaceous earth with 0.2 g or 1 g azadirachtin kg^-1 rice) was more effective than the single treatment in reducing numbers of surviving beetles.     

Reduced growth of Lucilia cuprina larvae fed serum from sheep treated with anthelmintics

The effect of three commonly used anthelmintics, levamisole hydrochloride, ivermectin and closantel, on the development of the sheep blowfly, Lucilia cuprina, was determined. Sheep were treated with each anthelmintic using the manufacturers' recommended dose for helminth control. Both ivermectin and closantel significantly (p < 0.05) reduced the growth rate of larvae of L cuprina cultured in vitro on serum from these sheep. Levamisole hydrochloride had no effect. Ivermectin was effective for less than 6 days after treatment, whereas closantel significantly reduced larval growth 21 days after treatment. Dose-response experiments showed that lower concentrations of both ivermectin and closantel were not as effective in reducing larval growth.     

Demodex spp. infestation and suspected demodicosis of alpacas (Vicugna pacos) in New Zealand

Extract

Ectoparasites known to cause skin lesions in alpacas (Vicugna pacos) include the mites Sarcoptes scabiei, Chorioptes bovis and Psoroptes spp., and the lice Microthoracius mazzai and Bovicola breviceps (Cicchino et al. 1998 Cicchino, AC, Munoz, Cobenas ME, Bulman, GM, Diaz, JC and Laos, A. 1998. Identification of Microthoracius mazzai (Phthiraptera: Anoplura) as an economically important parasite of alpacas. Journal of Medical Entomology, 35: 922–930.  [Google Scholar]; Foster et al. 2007 Foster, A, Jackson, A and D'alterio, GL. 2007. Skin diseases of South American camelids. In Practice, 29: 216–223. [Crossref], [Web of Science ®] , [Google Scholar]). Occasionally, Demodex spp. infestations have been reported or mentioned as incidental fi ndings in llamas (Lama glama) (Atlee et al. 1997 Atlee, BA, Stannard, AA, Fowler, ME, Willemse, T, Ihrke, PJ and Olivry, T. 1997. The histology of the normal llama skin. Veterinary Dermatology, 8: 165–176. [Crossref], [Web of Science ®] , [Google Scholar]) and alpacas (Foster et al. 2007 Foster, A, Jackson, A and D'alterio, GL. 2007. Skin diseases of South American camelids. In Practice, 29: 216–223. [Crossref], [Web of Science ®] , [Google Scholar]). So far, only Sarcoptes scabiei (McKenna et al. 2005 McKenna, PB, Hill, FI and Gillett, R. 2005. Sarcoptes scabiei infection on an alpaca (Lama pacos. New Zealand Veterinary Journal, 53: 213–213. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), Chorioptes bovis (Arthur 1997 Arthur, DG. 1997. Diseases of lamoids in New Zealand. Surveillance, 24(1): 29–30.  [Google Scholar], non-peer reviewed) and Bovicola breviceps (Palma et al. 2006 Palma, RL, McKenna, PB and Aitken, P. 2006. Confirmation of the occurrence of the chewing louse Bovicola (Lepikentron) breviceps (Insecta: Phthiraptera: Trichodectidae) on alpacas (Lamas pacos) in New Zealand. New Zealand Veterinary Journal, 54: 253–254. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) have been recorded on lamoids in New Zealand. Here, we report the first record of Demodex spp. infestation of an alpaca in New Zealand.