Septicaemia and meningitis caused by infection of New Zealand sea lion pups with a hypermucoviscous strain of Klebsiella pneumoniae

Hypervirulent Klebsiella pneumoniae in California Sea Lions (Zalophus californianus): Pathologic Findings in Natural Infections

“…2 In the case of New Zealand sea lions, bacterial invasion of white matter blood vessels and parenchyma was rare. 6 The presence of K2 K. pneumoniae on the oropharyngeal and intestinal mucosa could indicate that this bacterium inhabits these mucosae as normal flora, representing potential portals of entry to the lung and liver, but we cannot rule out that some of these bacteria represent postmortem overgrowth or expectorated and ingested microorganisms. In a similar manner, the presence of intact K2 K. pneumoniae in the distal renal tubules could indicate late bacteremic spread of this bacterium to the kidney with potential elimination through urine 7 or postmortem overgrowth.…”

“…3,7,9 In the past decade, rmpA-positive K. pneumoniae emerged as an important pathogen of nonhuman primates 8,9 and otariid seals. 5,6 In New Zealand sea lions (Phocarctos hookeri), K. pneumoniae infection is the most important cause of pup mortality, 6 and in California sea lions (CSLs) (Zalophus californianus), localized and disseminated hypervirulent K. pneumoniae infections have been a minor yet constant cause of strandings. 5 Detailed descriptions of K. pneumoniae pathology in CSLs and the distribution of the bacteria are not available in the literature yet are important to understanding its pathogenesis.…”

Pinnipediae

“…However, in 2002 a mass mortality event caused by K. pneumoniae occurred in New Zealand sea lion pups in the sub-Antarctic (Castinel et al, 2007). The causal isolate was later identified as a hypermucoviscous phenotype (Roe et al, 2015), but appears not to be of human origin (Castinel et al, 2007). A similar isolate has also been reported in CSLs (Jang et al, 2010;Seguel et al, 2017a).…”

“…Affected New Zealand sea lion pups have bacteremia and fibrinosuppurative to histiocytic inflammation of the meninges, joints, lymph nodes, respiratory tract, peritoneum, and subcutaneous tissues (Fig. 23.28) (Roe et al, 2015). Disease has not been reported in juveniles or adults.…”

No evidence of cryptic bycatch causing New Zealand sea lion population decline

“…(1) dismiss more probable causes of population decline (5). The authors (1) discount disease-induced mortality, although other sources quantify the negative population effect of Klebsiella pneumoniae-induced pup mortality estimates on subsequent breeder numbers (5,7). Meyer et al (1) found no influence of food limitation on NZSLs, whereas other research has identified multiple indicators of nutritional stress at the Auckland Islands, including adverse breeding rates (5).…”