Host Year Research Articles

New Zealand’s Hosting of APEC in 2021

Hosting APEC in 2021 is a unique and timely opportunity for New Zealand to take responsibility for providing regional leadership that can advance and sustain APEC as an institution, including through its development of trade and economic policies that will support the region’s economic recovery from the effects of Covid-19. This article reviews why APEC matters to New Zealand and the international context which will influence New Zealand’s APEC host year. It outlines how New Zealand will approach its virtual hosting of APEC 2021, and the key themes which will inform our priorities.

Opportunistic conspecific brood parasitism in a box-nesting population of Prothonotary Warblers (Protonotaria citrea)

ABSTRACT Conspecific brood parasitism (CBP), although prevalent in some avian taxa, is easily overlooked when it occurs in low frequencies, and therefore the ecology of this behavior has only occasionally been described in passerines. We describe the occurrence of CBP in a population of Prothonotary Warblers (Protonotaria citrea) breeding in nest boxes, demonstrate associated fitness costs, and investigate parasite strategy. We genotyped individuals at 6 microsatellite loci and used Cervus software to determine log-likelihood of maternity (LOD scores) for offspring and social mothers. We set critical cutoff LOD scores at 95% confidence for exclusion of the social mother and assignment of a parasite mother from the breeding population. Of 805 nestlings (233 family groups during 2009–2013), we found that 12.7% had genotypes that were incompatible with their social mother. Females with unrelated nestlings (hosts) fledged fewer biological offspring within the host year than nonhost females despite fledging mo...

Adipose tissue serves as a reservoir for recrudescent Rickettsia prowazekii infection in a mouse model.

Brill-Zinsser disease, the relapsing form of epidemic typhus, typically occurs in a susceptible host years or decades after the primary infection; however, the mechanisms of reactivation and the cellular reservoir during latency are poorly understood. Herein we describe a murine model for Brill-Zinsser disease, and use PCR and cell culture to show transient rickettsemia in mice treated with dexamethasone >3 months after clinical recovery from the primary infection. Treatment of similarly infected mice with cyclosporine failed to produce recrudescent bacteremia. Therapy with doxycycline for the primary infection prevented recrudescent bacteremia in most of these mice following treatment with dexamethasone. Rickettsia prowazekii (the etiologic agent of epidemic typhus) was detected by PCR, cell culture, and immunostaining methods in murine adipose tissue, but not in liver, spleen, lung, or central nervous system tissues of mice 4 months after recovery from the primary infection. The lungs of dexamethasone-treated mice showed impaired expression of β-defensin transcripts that may be involved in the pathogenesis of pulmonary lesions. In vitro, R. prowazekii rickettsiae infected and replicated in the murine adipocyte cell line 3T3-L1. Collectively these data suggest a role for adipose tissue as a potential reservoir for dormant infections with R. prowazekii.

Long‐term changes in the prevalence of two helminth parasites (Cestoda: Trypanorhyncha) infecting marine fish

Changes in prevalence of the plerocerci of Grillotia angeli Dollfus, 1969 in mackerel, Scomber scombrus L., and of Lacistorhynchus sp. in herring, Clupea harengus L., were recorded over periods of eight years (1978–1985) and 11 years (1974–1984), respectively. Data were collected from 21 year classes of mackerel in an area to the south‐west of Britain and Ireland and from seven year classes of herring in the eastern North Sea. Both sets of data showed sharp decreases in parasite prevalence from periods at relatively high levels to others at much lower levels. The changes in prevalence occurred at the same time in both host‐parasite systems and coincided with the end of the hydrographic phenomenon known as the mid‐70s salinity anomaly. Possible explanations for the changes which are discussed include changes in abundance of first intermediate and definitive hosts, variations in host year class strength, changes in hydrographic conditions and changes in host diet.

Pucciniastrum americanum . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Pucciniastrum americanum . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Pycnia and aecia on Picea glauca (= P. canadensis ), uredia and telia on Rubus idaeus (incl. R. strigosus ) and R . leucodermis (raspberries). DISEASE: Needle rust of white spruce. Late leaf rust or late yellow rust of raspberry, infecting canes, leaves, petioles, calyces and fruits. GEOGRAPHICAL DISTRIBUTION: Canada and U.S.A. (widely distributed, recorded from British Columbia, Connecticut, Idaho, Illinois, Iowa, Mass., Md, Me, Montana, North Dakota, New Hamp., New Jersey, Nova Scotia, New York, Ohio, Ontario, Quebec, Vermont, Wisconsin, West Virginia). TRANSMISSION: Although the basidiospores infect Picea glauca (white spruce) (Darker, 1929) in some areas they probably play little part in the life cycle on raspberry since this rust is found on the latter host year after year in regions remote from any spruce trees (Anderson, 1956).