Prevalence of a Septicemia Disease in the Crested Ibis (Nipponia nippon) in China

Abstract

This study investigated six cases of septicemia in young crested ibises (Nipponia nippon). These birds all died with similar clinical signs, including sudden death, anorexia, diarrhea, and lameness. Immediately after death, the birds were necropsied; a blood sample was taken from heart and tissues were sampled from liver, lung, spleen, peritoneal mucus, and feces for bacteriologic examination. Anatomic observation showed that the main findings common to the sick birds were arthrocele, associated with congestion in the femur, tibiotarsus, and ventral side; swelling in the liver; hemorrhagic pericarditis; miliary tubercles in lung; and fibrous tubercles in the synovial capsule of the knee joint with suppurative abscesses. Through bacterial examination, the colonial type of Escherichia coli strain was represented prominently in cultures of the feces, heart blood, liver, lung, spleen, suppurative mucus of the synovial capsule, and peritoneal exudate. These symptoms suggested that the death of a number of endangered crested ibis within a short period was evidence of septicemia. The bacterial inoculation tests were also conducted using domestic pigeon, native chicken, and mice for the presence of and infection with E coli. The study provided indications of the possible role of E. coli strains as bird pathogens and a potential risk in endangered species. Further work is needed to characterize E. coli strains and the toxin production in this bird. This disease occurrence also adds a note of caution to the continued efforts and interest in the reintroduction of the ibis back into its former wild ranges to ensure that formerly captive individuals do not transmit disease to the wild populations of its own or other sympatric species.

The first report of a Pelecaniformes defensin cluster: Characterization of β-defensin genes in the crested ibis based on BAC libraries

“…In recent years, there has been an increasing number of reports regarding infectious diseases in the crested ibis, including septicemia6, new castle2, Salmonella infection8, Escherichia coli infection5, avian influenza7, and others, which implies that this rare bird is at increasingly high risk under variable pathogen pressures. Identification of defensin genes responsive to certain pathogens has been conducted in many avian studies1234 but never in crested ibis.…”

“…However, as a bottlenecked species with intensive inbreeding, recent populations suffer from low genetic diversity3. The mortality of ibis embryos and nestlings is also high145, and many pathogens can fatally infect the bird2678. Therefore, the genetic conservation and immunological function of the crested ibis require rigorous investigation.…”

Genetic Diversity and Differentiation at Structurally Varying MHC Haplotypes and Microsatellites in Bottlenecked Populations of Endangered Crested Ibis

“…By analyzing the genomes of 57 historic and 8 modern samples, a recent study revealed ancestral loss of genetic variation and high deleterious mutation owing to genetic drift and inbreeding depression in current populations [32]. There have been a growing number of reports regarding various infections [33,34,35,36] and high mortality [29,33] in this bird, indicating frequent threats from pathogens and undetermined fitness. However, there has not yet been any large-scale genetic assessment on Nini populations.…”

Flexivirga lutea sp. nov., isolated from the faeces of a crested ibis, Nipponia nippon, and emended description of the genus Flexivirga

“…This low genetic diversity could increase susceptibility for infectious diseases. According to previous studies, the recovered crested ibis population was vulnerable to Escherichia coli septicemia due to its low level of divergence of major histocompatibility complex alleles (Xi et al, 2007;Zhang et al, 2006). For this reason, multilateral and continuous pathogen monitoring for the crested ibis is needed for effective species recovery.…”