The poultry industry in New Zealand

Extract

The term “chicken feed” used to be a synonym for insignificance. The domestic fowl was not of major significance economically in the New Zealand way of life. Over the past 15 years, however, their status has changed remarkably. Today the production of poultry is no longer a trivial or small-scale business. A few figures will illustrate the dimensions of the change. In 1955, commercial egg production is estimated to have been less than 40 million dozens of eggs annually, while today the comparable figure is some 75 million dozen. During the same period, the meat chicken industry has been established and annual production and consumption has grown to a figure in excess of 5 kg per capita.     

Pulsed-field gel electrophoresis typing of Campylobacter fetus subsp. fetus isolated from sheep abortions in New Zealand

AIMS: To genotype Campylobacter fetus subsp. fetus isolates cultured from sheep abortions submitted to diagnostic laboratories in New Zealand during the year 2000 breeding season. To compare the types found nationally with those found in the Hawke' Bay region in 1999, and strains held in the New Zealand Reference Culture Collection, Medical Section (NZRM) from a study published in 1987.

METHODS: Campylobacter fetus subsp. fetus isolates cultured by veterinary diagnostic laboratories in the year 2000 breeding season, from sheep abortions from throughout New Zealand, were typed using pulsed-field gel electrophoresis (PFGE). In addition, seven freeze-dried C. fetus subsp. fetus isolates (strain numbers 2939–2945) from the NZRM, representing restriction types a–g found amongst sheep abortion isolates in a study published in 1987, were typed using PFGE.

RESULTS: In total, 293 C. fetus subsp. fetus isolates from 200 farms were obtained from veterinary diagnostic laboratories. Twenty-two distinct PFGE profiles were identified amongst the isolates. PFGE type B1 was predominant in each region of New Zealand and was identified from 66% of farms overall. Of the C. fetus subsp. fetus restriction types a–g lodged with the NZRM, 3/7 had PFGE profiles indistinguishable from profiles found in the current study. The other four restriction types had PFGE profiles that were unique but similar to those found in the current study.

CONCLUSIONS: PFGE type B1 was predominant amongst the C. fetus subsp. fetus isolates cultured from sheep abortions in each region of New Zealand in the year 2000, as was found in Hawke' Bay in 1999. The similarity between PFGE profiles of C. fetus subsp. fetus sheep abortion isolates from 1987 and 2000, and the relative prevalence of the PFGE groups, suggests that there has been no major genotypic shift in the population of C. fetus subsp. fetus implicated in sheep abortion in New Zealand during this time.     

Pulsed-field gel electrophoresis typing of Campylobacter fetus subsp. fetus isolated from sheep abortions in New Zealand

AIMS: To genotype Campylobacter fetus subsp. fetus isolates cultured from sheep abortions submitted to diagnostic laboratories in New Zealand during the year 2000 breeding season. To compare the types found nationally with those found in the Hawke's Bay region in 1999, and strains held in the New Zealand Reference Culture Collection, Medical Section (NZRM) from a study published in 1987. METHODS: Campylobacter fetus subsp. fetus isolates cultured by veterinary diagnostic laboratories in the year 2000 breeding season, from sheep abortions from throughout New Zealand, were typed using pulsed-field gel electrophoresis (PFGE). In addition, seven freeze-dried C. fetus subsp. fetus isolates (strain numbers 2939-2945) from the NZRM, representing restriction types a-g found amongst sheep abortion isolates in a study published in 1987, were typed using PFGE. RESULTS: In total, 293 C. fetus subsp. fetus isolates from 200 farms were obtained from veterinary diagnostic laboratories. Twenty-two distinct PFGE profiles were identified amongst the isolates. PFGE type B1 was predominant in each region of New Zealand and was identified from 66% of farms overall. Of the C. fetus subsp. fetus restriction types a-g lodged with the NZRM, 3/7 had PFGE profiles indistinguishable from profiles found in the current study. The other four restriction types had PFGE profiles that were unique but similar to those found in the current study. CONCLUSIONS: PFGE type B1 was predominant amongst the C. fetus subsp. fetus isolates cultured from sheep abortions in each region of New Zealand in the year 2000, as was found in Hawke's Bay in 1999. The similarity between PFGE profiles of C. fetus subsp. fetus sheep abortion isolates from 1987 and 2000, and the relative prevalence of the PFGE groups, suggests that there has been no major genotypic shift in the population of C. fetus subsp. fetus implicated in sheep abortion in New Zealand during this time.     

The prevalence and genetic diversity of Campylobacter spp. in domestic 'backyard' poultry in Canterbury, New Zealand

Campylobacteriosis is the most commonly notified illness in New Zealand. Whilst the importance of commercial poultry in campylobacteriosis is well established, little is known about the possible role of chickens kept at home as a direct animal/faecal contact or consumption exposure pathway. The aim of this study was to determine the prevalence and genetic diversity of Campylobacter spp. in domestic backyard chicken flocks in the Canterbury region of New Zealand. Poultry faecal samples were collected from 35 domestic 'backyard' poultry flocks from urban and rural properties around the Canterbury Region of New Zealand. A total of 291 samples were collected and tested for the presence of thermotolerant Campylobacter spp. and positive isolates were analysed using pulsed-field gel electrophoresis (PFGE) using both SmaI and KpnI enzymes. There was a high prevalence of Campylobacter spp. with 86% of flocks testing positive. Campylobacter jejuni alone, Campylobacter coli alone and both C. jejuni and C. coli were detected in 20 (57%), 2 (6%) and 8 (23%) of the flocks respectively. SmaI/KpnI PFGE analysis identified 50 different genotypes across the 35 flocks. Genotype diversity richness was highest on the lifestyle block and farm properties with 43 different genotypes isolated, whilst urban properties displayed the least richness with 12 genotypes isolated. Rural flocks tended to have more different genotypes in a given flock than urban flocks. Comparison of the genotypes with the PulseNet Aotearoa Campylobacter database showed that 28 of the genotypes had previously been isolated from human cases of campylobacteriosis. Many of these were also indistinguishable from Campylobacter spp. previously isolated from retail chicken. Therefore, contact with backyard poultry or their faecal material is a potential additional infection pathway outside of exposure to the established pathways associated with the consumption of Campylobacter-contaminated commercial meat or foods cross-contaminated from contaminated poultry.     

Low levels of antibacterial drug resistance expressed by Gram-negative bacteria isolated from poultry carcasses in New Zealand

Abstract

AIM: To provide baseline data on the levels and patterns of antibacterial drug resistance expressed by Gram-negative bacteria isolated from poultry carcasses in New Zealand.

METHODS: Between July and December 2006, isolates of Escherichia coli (n=407) and Salmonella spp. (n=3) originating from carcass-rinse samples were submitted by testing laboratories affiliated to five major poultry processing plants. Isolates of Campylobacter jejuni (n=193) originating from retail poultry carcasses in 2005–2006 were retrieved from the Massey University archives. All isolates underwent disc diffusion susceptibility testing against panels of 12 (Enterobacteriaceae) and six (Campylobacter spp.) antibacterial drugs. Cephalothin-resistance in isolates of E. coli was confirmed using ETest strips, and confirmation of the resistance phenotypes for a subset of C. jejuni isolates used microbroth dilution assays. Patterns within the resistance phenotypes of the isolates were investigated using hierarchical clustering, and logistic regression modelling.

RESULTS: The majority of isolates (71.5% E. coli, 99% C. jejuni, and all three Salmonella spp. isolates) were fully susceptible to the drugs that were tested. Four (1%) E. coli isolates showed resistance to three or more drugs. The proportions of susceptible E. coli differed between the five processing plants. Resistances were detected in E. coli isolates, using disc diffusion to cephalothin (18.2%), ampicillin (4.4%), tetracycline (4.4%) and gentamicin (1.5%). There was an association between cephalothin-resistant isolates of E. coli and decreased susceptibility to gentamicin. Using ETests to ascertain the minimum inhibitory concentrations (MIC) of E. coli for cephalothin gave inconsistent results. One of 193 C. jejuni isolates was resistant to erythromycin, and microbroth dilution assays confirmed that this panel of C. jejuni was generally susceptible to antibacterial drugs.

CONCLUSIONS: The levels of resistance shown by Gram-negative bacteria isolated from chicken carcasses in New Zealand are among the lowest reported around the world. No resistance to extended-spectrum cephalosporin drugs was detected in E. coli, suggesting that CTX-M and AmpC beta-lactamases are rare or absent. Salmonella spp. are rarely isolated from poultry carcasses during routine testing in New Zealand, and the isolates identified during this study were fully susceptible to the drugs tested. A panel of C. jejuni isolates originating from retail poultry carcasses were susceptible to first-line and second-line antibacterial drugs. The use of cephalothin as a marker of resistance to first-generation cephalosporins may not be appropriate for non-type-specific E. coli of animal origin.     

Mycobacteria isolated from deer in New Zealand from 1970-1983

Mycobacterium bovis was isolated from 504 deer from 1970 to 1983. It was first isolated from feral red deer (Cervus elaphus) in New Zealand in 1970, and from farmed deer in 1978. Cervine tuberculosis has emerged as a significant problem in farmed deer and in 1983 M.bovis was found on 40 different farms. Thirty-five isolates of Mycobacterium avium-intracellulare have been cultured from deer but were associated with clinical disease in only four cases. Mycobacterium nonchromogenicum, Mycobacterium diernhoferi, Mycobacterium gastri, Mycobacterium chelonei, Mycobacterium smegmatis and Mycobacterium vaccae were isolated from deer but were not considered to be pathogenic.     

Infectious bursal disease serology in New Zealand poultry flocks

Extract

Madam:– Infectious bursal disease (IBD) is recognised as a serious economically significant disease of poultry. N.H. Christensen in his letter to your Journal (1) has summarised the ways in which IBD causes such economic loss.     

Campylobacter jejuni in poultry giblets

A total of 200 poultry giblets, 50 each of chickens, ducks, squab and turkeys, were examined for the presence of Campylobacter jejuni. In chicken giblets, C. jejuni was isolated from gizzards, hearts, livers and spleens with incidences of 28%, 10%, 40% and 16% respectively while 24%, 6%, 36% and 10% of duck gizzards, hearts, livers and spleens were positive for the organism, respectively. C. jejuni was detected in 6% of squab gizzards, in 10% of squab livers but failed to be detected in squab hearts & spleens. In turkey giblets, 16% of gizzards, 4% of hearts, 30% of livers and 8% of spleens were positive for the organism. C. jejuni was more frequently isolated from liver samples than gizzard, spleen and heart samples, each constituting of 29%, 18.5%, 8.5% and 5%, respectively. High incidence of C. jejuni was recorded among chicken giblets (23.5%), followed by duck giblets (19%), then turkey giblets (14.5%) and finally squab giblets (4%).     

Phage typing of staphylococci isolated from dairy cows in New Zealand

Four red deer calves (Cervus elaphus) died with severe nephritis apparently associated with infection by Leptospira interrogans serovar pomona. The sera of 12 in-contact red deer calves were examined for leptospiral agglutinins and nine showed titres to pomona consistent with recent infection. Two also showed titres of 1:100 to serovar hardjo. The urine of five of these in-contact calves was examined periodically over a period of nine months. All were initially leptospiruric, four being infected with pomona and one with hardjo. In four animals leptospiruria could only be detected for up to six months, but one animal infected with pomona was leptospiruric for at least eight months.

The apparent source of infection was from infected cattle, and it is suggested that deer are unlikely to act as maintenance hosts for serovar pomona.     

Characterization of two strains of adenovirus isolated from New Zealand sheep

Two strains of adenovirus were isolated from a flock of lambs sampled regularly for 10 months. The first strain was isolated in January from nasal secretions. The second strain was isolated in May and June from nasal secretions, faeces and lung tissue. Representative isolates were identified as adenoviruses on the basis of their morphology, physico-chemical characteristics and the presence of the adenovirus group-specific antigen. The two isolates selected for characterization were serologically dictinct by cross-neutralization tests. They also differed in their behaviour in tissue culture and in their ability to agglutinate chicken erythrocytes.     

"养鸡生产中沙门氏菌病的预防与控制策略"专栏(四)沙门氏杆菌和弯曲杆菌在家禽群体中的动态变化特征

难道我们不想掌控自身命运吗?虽然这是-个很广博的问题,但如果你在考虑幼龄肉鸡群沙门氏菌感染这个特定话题以及考虑它与人食源性疾病可能的关系时,这个问题就具有特殊的意义.出席美国国家家禽改良计划(the National Poultry Improvement Plan,NPIP)第40届年会(两年一次)的大多数代表,在投票是否采用美国肉鸡扩繁群肠炎沙门氏菌监测方案时,对该特殊问题给出了肯定回答.     

Prevalence of antibodies to infectious laryngotracheitis virus in poultry in New Zealand

Abstract

Extract

Infectious laryngotracheitis (ILT) is an acute respiratory disease of fowls which was first reported from the U.S.A. by May and Tittsler (1925) Adlakha, S. C. 1966. A serological investigation to determine respiratory infections of poultry in India. Avian Dis., 10: 401–404.  [Google Scholar]. Both severe acute forms with high mortality and chronic enzootic forms with low mortality have been described, and the earlier literature was reviewed by Jordan (1966) Chang, P. W., Yates, V. J., Dardiri, A. H. and Fry, D. E. 1960. Some observations of the propagation of infectious laryngotracheitis virus in tissue culture. Avian Dis., 4: 384–390.  [Google Scholar]. In New Zealand ILT virus was first isolated in 1957 (Webster, 1959 Hitcher, S. B., Shea, C. A. and White, P. G. 1958. Studies on a serum neutralization test for the diagnosis of laryngotracheitis in chickens. Avian Dis., 2: 258–269.  [Google Scholar]).