New Structures of the O-Specific Polysaccharides of Bacteria of the Genus Proteus. 1. Phosphate-Containing Polysaccharides

The O-specific polysaccharide chains (O-antigens) of the lipopolysaccharides of five Proteus strains, P. vulgaris O17, P. mirabilis O16 and O33, and P. penneri 31 and 103, were found to contain phosphate groups that link the non sugar components, e.g., ethanolamine and ribitol. The polysaccharides of P. mirabilis O16 and P. penneri 103 include ribitol phosphate in the main chain and thus resemble ribitol teichoic acids of Gram-positive bacteria. The structures of the polysaccharides were elucidated using NMR spectroscopy, including two-dimensional ¹H, ¹H correlation spectroscopy (COSY and TOCSY), nuclear Overhauser effect spectroscopy (NOESY or ROESY), and H-detected ¹H, ¹³C and ¹H, ³¹P heteronuclear multiple-quantum coherence spectroscopy (HMQC), along with chemical methods. The structures determined are unique among the bacterial polysaccharides and, together with the data obtained earlier, represent the chemical basic for classification of Proteus strains. Based on structural similarities of the O-specific polysaccharides and serological relationships between the O-antigens, we propose to extend Proteus serogroups O17 and O19 by including P. penneri strains 16 and 31, respectively.     

Two New Species of Anastrepha Schiner (Diptera, Tephritidae) Closely Related to Anastrepha pickeli Lima

Anastrepha entodonta n. sp. and Anastrepha hadropickeli n. sp. are described and illustrated. The new species belong to the spatulata group. Both species occur sympatrically with Anastrepha pickeli Lima in the semiarid region of the state of Minas Gerais, Brazil. Anastrepha hadropickeli occurs also in the semiarid of the state of Rio Grande do Norte, Brazil, where it was misidentified as A. pickeli.     

Polynucleotide Sequence Divergence Among Strains of Escherichia coli and Closely Related Organisms

Polynucleotide sequence similarity tests were carried out to determine the extent of divergence present in a number of Escherichia coli strains, obtained from diverse human, animal, and laboratory sources, and closely related strains of Shigella, Salmonella, and the Alkalescens-Dispar group. At 60 C, relative reassociation of deoxyribonucleic acid (DNA) from the various strains with E. coli K-12 DNA ranged from 100 to 36%, with the highest level of reassociation found for three strains derived from K-12, and the lowest levels for two “atypical” E. coli strains and S. typhimurium. The change in thermal elution midpoint, which indicates the stability of DNA duplexes, ranged from 0.1 to 14.5 C, with thermal stability closely following the reassociation data. Reassociation experiments performed at 75 C, at which temperature only the more closely related DNA species form stable duplexes, gave similar indications of relatedness. At both temperatures, Alkalescens-Dispar strains showed close relatedness to E. coli, supporting the idea that they should be included in the genus Escherichia. Reciprocal binding experiments with E. coli BB, 02A, and K-12 yielded different reassociation values, suggesting that the genomes of these strains are of different size. The BB genome was calculated to be 9% larger than that of K-12, and that of 02A 9% larger than that of BB. Calculation of genome size for a series of E. coli strains yielded values ranging from 2.29 × 10⁹ to 2.97 × 10⁹ daltons. E. coli strains and closely related organisms were compared by Adansonian analysis for their relatedness to a hypothetical median strain. E. coli 0128a was the most closely related to this median organism. In general, these data compared well with the data from reassociation experiments among E. coli strains. However, anomalous results were obtained in the cases of Shigella flexneri, S. typhimurium, and “atypical” E. coli strains.     

中国石蕊属地衣新记录种及其与近缘谱系的分化（英文）

在中国石蕊属种类的研究中,依据形态特征及nrD NA ITS序列数据,鉴定出采自海南的一新记录种——粗糙石蕊(Cladonia rudis)。提供了描述及图片,依据序列数据估计了其与近缘谱系的分化时间。     

High Variation of Fluorescence Protein Maturation Times in Closely Related Escherichia coli Strains

Fluorescent proteins (FPs) are widely used in biochemistry, biology and biophysics. For quantitative analysis of gene expression FPs are often used as marking molecules. Therefore, sufficient knowledge of maturation times and their affecting factors is of high interest. Here, we investigate the maturation process of the FPs GFP and mCherry expressed by the three closely related Escherichia coli strains of the Colicin E2 system, a model system for colicinogenic interaction. One strain, the C strain produces Colicin, a toxin to which the S strain is sensitive, and against which the R strain is resistant. Under the growth conditions used in this study, the S and R strain have similar growth rates, as opposed to the C strain whose growth rate is significantly reduced due to the toxin production. In combination with theoretical modelling we studied the maturation kinetics of the two FPs in these strains and could confirm an exponential and sigmoidal maturation kinetic for GFP and mCherry, respectively. Our subsequent quantitative experimental analysis revealed a high variance in maturation times independent of the strain studied. In addition, we determined strain dependent maturation times and maturation behaviour. Firstly, FPs expressed by the S and R strain mature on similar average time-scales as opposed to FPs expressed by the C strain. Secondly, dependencies of maturation time with growth conditions are most pronounced in the GFP expressing C strain: Doubling the growth rate of this C strain results in an increased maturation time by a factor of 1.4. As maturation times can vary even between closely related strains, our data emphasize the importance of profound knowledge of individual strains'' maturation times for accurate interpretation of gene expression data.     

Heterodera graminophila n. sp. (Nematoda Heteroderae) from Grass with a Key to Closely Related Species

Heterodera graminophila n. sp., a member of the H. goettingiana group, is described and illustrated from roots of barnyard grass, Echinochloa colonum (L.) Link, in Baton Rouge, La. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau &Cobb, 1962, and H. graminis Stynes, 1971, but differs particularly in having a small, inconspicuous anus without a circum-anal pattern and located about 20% of the cyst length from the vulval cone terminus, and a longer vulval slit averaging 45 μ in length. A key, based on cyst and larval characters, is presented for identification of the 10 Heterodera species in the H. goettingiana group.     

Vesicle-Mediated Transfer of Virulence Genes from Escherichia coli O157:H7 to Other Enteric Bacteria

Membrane vesicles are released from the surfaces of many gram-negative bacteria during growth. Vesicles consist of proteins, lipopolysaccharide, phospholipids, RNA, and DNA. Results of the present study demonstrate that membrane vesicles isolated from the food-borne pathogen Escherichia coli O157:H7 facilitate the transfer of genes, which are then expressed by recipient Salmonella enterica serovar Enteritidis or E. coli JM109. Electron micrographs of purified DNA from E. coli O157:H7 vesicles showed large rosette-like structures, linear DNA fragments, and small open-circle plasmids. PCR analysis of vesicle DNA demonstrated the presence of specific genes from host and recombinant plasmids (hly, L7095, mobA, and gfp), chromosomal DNA (uidA and eaeA), and phage DNA (stx1 and stx2). The results of PCR and the Vero cell assay demonstrate that genetic material, including virulence genes, is transferred to recipient bacteria and subsequently expressed. The cytotoxicity of the transformed enteric bacteria was sixfold higher than that of the parent isolate (E. coli JM109). Utilization of the nonhost plasmid (pGFP) permitted the evaluation of transformation efficiency (ca. 10³ transformants μg of DNA⁻¹) and demonstrated that vesicles can deliver antibiotic resistance. Transformed E. coli JM109 cells were resistant to ampicillin and fluoresced a brilliant green. The role vesicles play in genetic exchange between different species in the environment or host has yet to be defined.     

Like Will to Like: Abundances of Closely Related Species Can Predict Susceptibility to Intestinal Colonization by Pathogenic and Commensal Bacteria

The intestinal ecosystem is formed by a complex, yet highly characteristic microbial community. The parameters defining whether this community permits invasion of a new bacterial species are unclear. In particular, inhibition of enteropathogen infection by the gut microbiota ( = colonization resistance) is poorly understood. To analyze the mechanisms of microbiota-mediated protection from Salmonella enterica induced enterocolitis, we used a mouse infection model and large scale high-throughput pyrosequencing. In contrast to conventional mice (CON), mice with a gut microbiota of low complexity (LCM) were highly susceptible to S. enterica induced colonization and enterocolitis. Colonization resistance was partially restored in LCM-animals by co-housing with conventional mice for 21 days (LCM^con21). 16S rRNA sequence analysis comparing LCM, LCM^con21 and CON gut microbiota revealed that gut microbiota complexity increased upon conventionalization and correlated with increased resistance to S. enterica infection. Comparative microbiota analysis of mice with varying degrees of colonization resistance allowed us to identify intestinal ecosystem characteristics associated with susceptibility to S. enterica infection. Moreover, this system enabled us to gain further insights into the general principles of gut ecosystem invasion by non-pathogenic, commensal bacteria. Mice harboring high commensal E. coli densities were more susceptible to S. enterica induced gut inflammation. Similarly, mice with high titers of Lactobacilli were more efficiently colonized by a commensal Lactobacillus reuteri ^RR strain after oral inoculation. Upon examination of 16S rRNA sequence data from 9 CON mice we found that closely related phylotypes generally display significantly correlated abundances (co-occurrence), more so than distantly related phylotypes. Thus, in essence, the presence of closely related species can increase the chance of invasion of newly incoming species into the gut ecosystem. We provide evidence that this principle might be of general validity for invasion of bacteria in preformed gut ecosystems. This might be of relevance for human enteropathogen infections as well as therapeutic use of probiotic commensal bacteria.     

Drug Resistance of Enteric Bacteria VIII. Chromosomal Location of Nontransferable R Factor in Escherichia coli

The R₂₁(TC) factor, obtained by transduction of the R₁₀(TC.CM.SM.SA) factor with phage ε to group E Salmonella, is not transferable by the normal conjugal process. However, when R₂₁(TC)⁺ transductants are infected with the F₁₃ factor, the nontransferable R₂₁(TC) factor acquires transmissibility by conjugation. R₂₁(TC)⁺ conjugants of Escherichia coli K-12, to which only the R₂₁(TC) factor was transmitted by cell-to-cell contact from an F′ R⁺ donor, were still unable to transfer their R₂₁(TC) factor by conjugation. In crosses between Hfr and F⁻E. coli K-12 strains containing R₂₁(TC), the gene responsible for tetracycline resistance was located on the E. coli K-12 chromosome between lac and pro, near lac.     

New Species of Closely Related Endosymbiotic Dinoflagellates in the Greater Caribbean have Niches Corresponding to Host Coral Phylogeny

Symbiotic dinoflagellates in the genus Breviolum (formerly Symbiodinium Clade B) dominate coral communities in shallow waters across the Greater Caribbean. While some formally described species exist, mounting genetic, and ecological evidence indicate that numerous more comprise this genus, many of which are closely related. To test this, colonies of common reef‐building corals were sampled across a large geographical range. Phylogenetic and population genetic markers then used to examine evolutionary divergence and delineate boundaries of genetic recombination. Three new candidate species were distinguished by fixed differences in nucleotide sequences from nuclear and chloroplast DNA. Population connectivity was evident within each lineage over thousands of kilometers, however, substantial genetic structure persisted between lineages co‐occurring within sampling locations, signifying reproductive isolation. While geographically widespread with overlapping distributions, each species is ecologically distinct, exhibiting specific mutualisms with phylogenetically distinct coral hosts. Moreover, significant differences in mean cell sizes provide some morphological evidence substantiating formal species distinctions. In providing evidence that satisfies the biological, phylogenetic, ecological, and morphological species concepts, we classify and formally name Breviolum faviinorum n. sp., primarily associated with Caribbean corals belonging to the Caribbean subfamily Faviinae; B. meandrinium n. sp., associated with corals belonging to the family Meandrinidae; and B. dendrogyrum n. sp., a symbiont harbored exclusively by the threatened coral Dendrogyra cylindrus. These findings support the primary importance of niche diversification (i.e. host habitat) in the speciation of symbiotic dinoflagellates.     

Genetic Divergence of Far-Eastern Dace Species Belonging to the Genus Tribolodon (Pisces, Cyprinidae) and Closely Related Taxa

Based on a biochemical–genetic approach, heterozygosity and divergence of structural genes at 30 enzyme loci were analyzed in six dace species. In addition, intra- and interspecific divergence of gene expression was analyzed based on a sample of 12 to 15 loci. Mean heterozygosities per individual varied as follows: Tribolodon species, H _obs = 0.007 ± 0.007 and H _exp = 0.007 ± 0.007; T. ezoe, H _obs = 0.045 ± 0.016 and H _exp = 0.067 ± 0.029. Several variants of genetic distances were estimated. Standard Nei's distances (D _N) varied from 0.145 to 0.284 in four dace species studied. As related to Tribolodon dace species, the following genetic distances were obtained for two members of other genera:Pseudaspius leptocephalus, D _N = 0.269; Leuciscus waleckii, D _N = 0.769. Based on the distance matrices, different clustering algorithms were realized. The main feature shared by different dendrograms was a separate position of the cluster joining Far-Eastern dace species, to whichP. leptocephalus and L. waleckii are successively added. Among the species studied, the proportion of loci similar by expression (E) varied from 87 to 100%. The greatest difference was found between landlocked and landlocked ecotypes of T. hakonensis, E = 67%. The following conclusions can be made: (1) Four studied species of the genus Tribolodon are rather well genetically differentiated. Diagnostic loci are available. (2) A nominal dace species, T. species, should be considered the fourth unambigous species of this genus, which is confirmed by its recent zoological acceptance of this species. (3) The origin and divergence of dace species belonging to the genus Tribolodon are relatively late (1 to 3 Myr ago) historical events. (4) Taxonomically, the genus Tribolodon belong to the tribe Pseudaspinini together with P. leptocephalus, which is confirmed by genetic data. (5) Data on heterozygosity and the divergence of structural and regulatory elements of genome, along with the proposed scheme of speciation types, suggest the following speciation modes for the species studied: for four species, adaptive divergence and for two species, genetic transformation.     

Six New Species of the Genus Thinodromus Kraatz, 1857, Closely Related to Thinodromus (Amisammus) ripicola (Cameron, 1941) (Coleoptera,Staphylinidae: Oxytelinae)

Entomological Review - The following six new species of the genus Thinodromus Kraatz, 1857, closely related to Th. (Amisammus) ripicola (Cameron, 1941) and Th. (A.) latus Gildenkov, 2003, are...     

Molecular Phylogenetic Analysis of the Endemic Far Eastern Closely Related Oxytropis Species of Section Orobia (Fabaceae)

Russian Journal of Genetics - The questions about the taxonomic status and phylogenetic relationships of the Far Eastern closely related species Oxytropis ochotensis, O. litoralis, O. erecta, O....     

Characterization and Evolution of mariner Elements from Closely Related Species of Fruit Flies (Diptera: Tephritidae)

Mariner elements were amplified using the polymerase chain reaction from two species of tephritid flies, Ceratitis rosa and Trirhithrum coffeae. The sequences were ∼1.3 kb in length. None of these elements appeared to be functional, as in every case the open reading frame (ORF) was disrupted by the presence of frameshifts or stop codons. These elements, Crmar1 and Tcmar1, are very similar to the Ccmar1 element previously amplified from the closely related tephritid species C. capitata and are members of the mellifera subfamily of mariner elements. The phylogeny and pattern of divergence of these elements were examined in relation to the phylogeny of the host species. It is highly probable that the elements were present in the ancestral lineage prior to the divergence of the three species. The copy numbers of the elements within each species are very different, ranging from about 10 in T. coffeae to 5,000 in C. rosa. The possible mechanisms which determine the copy number of an element in the host genome are discussed. Received: 25 April 1997 / Accepted: 31 July 1997     

Peptide Ligands That Bind Selectively to Spores of Bacillus subtilis and Closely Related Species

As part of an effort to develop detectors for selected species of bacterial spores, we screened phage display peptide libraries for 7- and 12-mer peptides that bind tightly to spores of Bacillus subtilis. All of the peptides isolated contained the sequence Asn-His-Phe-Leu at the amino terminus and exhibited clear preferences for other amino acids, especially Pro, at positions 5 to 7. We demonstrated that the sequence Asn-His-Phe-Leu-Pro (but not Asn-His-Phe-Leu) was sufficient for tight spore binding. We observed equal 7-mer peptide binding to spores of B. subtilis and its most closely related species, Bacillus amyloliquefaciens, and slightly weaker binding to spores of the closely related species Bacillus globigii. These three species comprise one branch on the Bacillus phylogenetic tree. We did not detect peptide binding to spores of several Bacillus species located on adjacent and nearby branches of the phylogenetic tree nor to vegetative cells of B. subtilis. The sequence Asn-His-Phe-Leu-Pro was used to identify B. subtilis proteins that may employ this peptide for docking to the outer surface of the forespore during spore coat assembly and/or maturation. One such protein, SpsC, appears to be involved in the synthesis of polysaccharide on the spore coat. SpsC contains the Asn-His-Phe-Leu-Pro sequence at positions 6 to 10, and the first five residues of SpsC apparently must be removed to allow spore binding. Finally, we discuss the use of peptide ligands for bacterial detection and the use of short peptide sequences for targeting proteins during spore formation.     

Cypripedium subtropicum,a New Species Related to Selenipedilum

Cypripedium subtropicum S. C. Chen et K. Y. Lang is a phytogeographycally significant new species with its habit, inflorescence and column very similar to those of Selenipedilum of tropical America. It is found in Mêdog of southeastern Xizang, China. Its slender leafy stem bears at the summit a many-flowered raceme, amounting to 1.5 m in height. Although its ovary is unilocular—this is the reason why we place it in Cypripedium, the column characters resemble those of Selenipedilum. For example, the staminode is rather small and its long stalk is very similar in texture and color to the filament of the fertile stamens. Obviously, it is a primitive new species related to Selenipedilum based on the similarities mentioned above. In the subfamily Cypripedioideae, as generally recognized, Selenipedilum is the most primitive genus, from which or whose allies Cypripedium is derived. Of phytogeographical significance is the fact that Selenipedilum occurs in Central America and northern South America, while a cypripedium akin to it is discontinuously distributed in subtropical Asia. This suggests that Selenipedilum or Selenipedilum-like form be once continually distributed in North America and eastern Asia when the climate there was warmer, as it is in the subtropics today. The floristic relationship between Central America and subtropical Asia appears to be closer than expected, as shown by the distribution patterns of Tropidia, Erythrodes, etc. Based on the occurrence of all six sections and particularly the most primitive form in eastern Asia, Cypripedium seems to be of Asian, rather than Central American, origin. Selenipedilum possesses some very primitive characters, such as trilocular ovary, vanilla-scented fruit, seed with sclerotic testa, simple column and more or less suffrutescent habit. The latter is considered by Dahlgren & Clifford (1982) to be one of ancestral characters of monocotyledons, which is now very rare not only in Orchidaceae but also in all monocotyledons. It is indeed necessary to make further investigations on Selenipedilum and also the new species pub-lished here, as well as a detailed comparison between them.     

Drug Resistance of Enteric Bacteria XIII. Distribution of R Factors in Escherichia coli Strains Isolated from Livestock

Escherichia coli strains isolated from 151 swine and 108 fowl, which were kept at the Animal Health Center, Maebashi, Japan, were surveyed for drug resistance and distribution of R factors. All of the swine and 38% of the fowl excreted E. coli strains resistant to tetracycline, chloramphenicol, streptomycin, and sulfanilamide, or certain combinations thereof. Among 278 resistant cultures isolated from swine, 13% were found to be resistant to one antibiotic, whereas 87% were resistant to more than one antibiotic. Among these resistant strains, 40% carried R factors which were transferable by the usual conjugal process. The resistance patterns of these R factors included 36% which were singly resistant and 64% which were multiply resistant. Among 54 resistant cultures isolated from fowl, 24% were singly resistant and 76% were multiply resistant. Of the resistant strains from fowl, 22% carried R factors. The resistance patterns of R factors included 50% of the singly resistant type and 50% which were multiply resistant. In spite of feeding with dairy products containing only tetracycline, a high incidence of multiple resistance was observed in the E. coli strains and the R factors isolated from these animals.     

Migratory New World Blackbirds (Icterids) Are More Neophobic than Closely Related Resident Icterids

Environments undergo short-term and long-term changes due to natural or human-induced events. Animals differ in their ability to cope with such changes which can be related to their ecology. Changes in the environment often elicit avoidance reactions (neophobia) which protect animals from dangerous situations but can also inhibit exploration and familiarization with novel situations and thus, learning about new resources. Studies investigating the relationship between a species’ ecology and its neophobia have so far been restricted to comparing only a few species and mainly in captivity. The current study investigated neophobia reactions to experimentally-induced changes in the natural environment of six closely-related blackbird species (Icteridae), including two species represented by two distinct populations. For analyses, neophobic reactions (difference in number of birds feeding and time spent feeding with and without novel objects) were related to several measures of ecological plasticity and the migratory strategy (resident or migratory) of the population. Phylogenetic relationships were incorporated into the analysis. The degree of neophobia was related to migratory strategy with migrants expressing much higher neophobia (fewer birds feeding and for a shorter time with objects present) than residents. Furthermore, neophobia showed a relationship to diet breadth with fewer individuals of diet generalists than specialists returning when objects were present supporting the dangerous niche hypothesis. Residents may have evolved lower neophobia as costs of missing out on opportunities may be higher for residents than migrants as the former are restricted to a smaller area. Lower neophobia allows them approaching changes in the environment (e.g. novel objects) quickly, thereby securing access to resources. Additionally, residents have a greater familiarity with similar situations in the area than migrants and the latter may, therefore, initially stay behind resident species.     

Isoprene Production Via the Mevalonic Acid Pathway in Escherichia coli (Bacteria)

There is a need to develop renewable fuels and chemicals that will help meet global demands for energy and synthetic chemistry feedstock, without contributing to climate change or environmental degradation. Isoprene (C₅H₈) is one such key chemical ingredient, required for the production of synthetic rubber or plastic products, and a potential biofuel. Enabling a sustainable microbial fermentation for the production of isoprene is an attractive alternative to a petroleum origin. This work demonstrates transgenic expression of the Pueraria montana (kudzu vine) isoprene synthase gene (kIspS) and heterologous isoprene production in Escherichia coli. Enhancements in the amount of E. coli isoprene production were achieved upon over-expression of the native 2-C-methyl-d-erythritol-4-phosphate (MEP) biosynthetic pathway and, independently, upon heterologous over-expression of the entire mevalonic acid (MVA) pathway. A direct comparison of the efficiency of cellular organic carbon flux through the MEP and MVA pathways is provided, under conditions when these are expressed in the same host using the same plasmid, and same ribosome-binding sites (RBS). These alternative isoprenoid biosynthetic pathways were assembled in and expressed through a superoperon, suitable for transformation of E. coli. Introduction of specific RBS and nucleotide spacers between individual genes in the superoperon structure enabled maximal expression in E. coli batch cultures and translated to an improved production from 0.4?mg isoprene per liter of culture (control) to 5?mg isoprene per liter of culture (MEP superoperon transformants) and up to 320?mg isoprene per liter of culture (MVA superoperon transformants). This 800-fold increase in isoprene concentration from the MVA transformants and the attendant isoprene-to-biomass 0.78:1 carbon partitioning ratio suggested that the engineered MVA pathway introduces a bypass in the flux of endogenous substrate in E. coli to isopentenyl-diphosphate and dimethylallyl-diphosphate, thus overcoming flux limitations imposed upon the regulation of the native MEP pathway by the cell.     

Enteric Infection and Subsequent Septicemia due to Attaching and Effacing Escherichia coli in a Chinchilla

An adult male chinchilla (Chinchilla lanigera) presented with severe lethargy and tachypnea; the physical examination was otherwise unremarkable. Due to the animal''s clinical condition, it was submitted for necropsy but died immediately prior to euthanasia. Clinicopathologic findings included leukocytosis with a left-shift neutrophilia and lymphopenia, azotemia, hyperphosphatemia, hyperglycemia, hyperlipemia, electrolyte imbalance, cholestasis, and hepatocellular damage. Neutrophilic enteritis with gram-negative bacterial colonization, hepatic lipidosis, interstitial pneumonia, suppurative tubulonephritis, erosive gastritis, cerebral edema, and lymphoid depletion were present microscopically. Attaching and effacing, eae-positive, Escherichia coli characterized by the presence of the intimin virulence factor was isolated from both the kidney and spleen. The cause of death was attributed to acute E. coli septicemia and subsequent disseminated intravascular coagulation.Abbreviations: AEEC, attaching and effacing E. coli.A black-gray, adult (age, unknown) male, experimentally naïve chinchilla (Chinchilla lanigera) purchased (Moulton Chinchilla Ranch, Rochester, MN) approximately 1 y previously, presented with extreme lethargy and tachypnea during daily health rounds. The chinchilla was group housed with 2 cage mates in accordance with the Guide for the Care and Use of Laboratory Animals⁹ in an AAALAC-accredited facility. A total of 12 nonSPF chinchillas were acquired together from the same vendor. The chinchillas were housed in a self-contained isolation cubicle within a diverse-species room, which included mice, rats, guinea pigs, and gerbils. The cubicle was maintained at negative pressure with regard to the room. Housing consisted of a modified stainless steel chicken brooder (Alternative Design Manufacturing and Supply, Siloam Springs, AR). The chinchilla was fed a daily ration of pelleted diet (Mazuri Chinchilla Diet 5M01, PMI Nutrition International, Richmond, IN) and maintained on filtered chlorinated municipal water via a glass bottle with a rubber stopper and stainless steel sipper. Caging, feeding bowls, and water bottles were sent to the cage washing area for sanitation. Cage components were sanitized in a rack washer (Better Built Rack Washer, Northwest Systems, Delta, Canada) that provided a 180 °F final water rinse. A blend of organic and inorganic acid detergent (Acidulate 28, Quip Labs, Wilmington, DE) was used during the wash cycle to remove urine deposits and proteinaceous debris. Environmental enrichment included the provision of hide boxes, biweekly dust baths (Critter Bath Powder, Central Garden and Pet, Walnut Creek, CA), certified wood gnawing blocks (Bio-Serv, Frenchtown, NJ), and western timothy hay (Oxbow Animal Health, Murdock, NE). Room conditions included 18.3 to 20.0 °C (65 to 68 °F), 35% to 40% relative humidity, and a 12:12-h light:dark cycle. Routine health monitoring consisted of daily observations by the husbandry and veterinary technical staff for clinical signs of illness. No deviations in appetite or other gross abnormalities were noticed prior to the animal''s illness.On physical examination, the chinchilla was moribund and responsive only when prodded. Copious fecal pellets were palpated on abdominal examination. The animal weighed 560 g and was in good body condition. The chinchilla was submitted immediately for necropsy but died prior to euthanasia. Subsequently, approximately 2 mL of blood was withdrawn by cardiocentesis for hematology and chemistry. Chinchilla-specific reference intervals were not available from the laboratory; therefore, published reference intervals were used as a guide for interpretation of the hematology and clinical chemistry results.²⁴