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What can we gain from co-analyzing experimental cultures, regionalization, and disciplinary phenomena of late twentieth century life sciences under our historiographic looking glass? This essay investigates the potential of such a strategy for the case of cell biology after 1960. By merging perspectives from historical epistemology inspired by the work of Hans-Jörg Rheinberger with a focus on boundary work in the realm of scientific publishing, community building, and disciplinary norms, a set of understudied scientific practices is exposed. These practices, historically subsumed under the label descriptive, have been as central in cell biology as hypothesis-driven research aiming at mechanistic explanations of cellular function. Against the background of an increasing molecular-mechanistic imperative in cell biology since the late 1960s, knowledge from descriptive practices was often judged as having low value but was nonetheless frequently cited and considered essential. Investigating the underlying epistemic practices and their interactions with disciplinary gatekeeping phenomena (as policed by journals and learned societies) provides historiographic access to the plurality of experimental cultures of cell biology, scattered into many interdisciplinary research fields-with some of them only partially engaged with mechanistic questions., (© 2022 The Authors. Berichte zur Wissenschaftsgeschichte published by Wiley-VCH GmbH.)

Cellular reproduction defines life, yet our textbook-level understanding of cell division is limited to a small number of model organisms centered around humans. The horizon on cell division variants is expanded here by advancing insights on the fascinating cell division modes found in the Apicomplexa, a key group of protozoan parasites. The Apicomplexa display remarkable variation in offspring number, whether karyokinesis follows each S/M-phase or not, and whether daughter cells bud in the cytoplasm or bud from the cortex. We find that the terminology used to describe the various manifestations of asexual apicomplexan cell division emphasizes either the number of offspring or site of budding, which are not directly comparable features and has led to confusion in the literature. Division modes have been primarily studied in two human pathogenic Apicomplexa, malaria-causing Plasmodium spp. and Toxoplasma gondii , a major cause of opportunistic infections. Plasmodium spp. divide asexually by schizogony, producing multiple daughters per division round through a cortical budding process, though at several life-cycle nuclear amplifications stages, are not followed by karyokinesis. T. gondii divides by endodyogeny producing two internally budding daughters per division round. Here we add to this diversity in replication mechanisms by considering the cattle parasite Babesia bigemina and the pig parasite Cystoisospora suis . B. bigemina produces two daughters per division round by a "binary fission" mechanism whereas C. suis produces daughters through both endodyogeny and multiple internal budding known as endopolygeny. In addition, we provide new data from the causative agent of equine protozoal myeloencephalitis (EPM), Sarcocystis neurona , which also undergoes endopolygeny but differs from C. suis by maintaining a single multiploid nucleus. Overall, we operationally define two principally different division modes: internal budding found in cyst-forming Coccidia (comprising endodyogeny and two forms of endopolygeny) and external budding found in the other parasites studied (comprising the two forms of schizogony, binary fission and multiple fission). Progressive insights into the principles defining the molecular and cellular requirements for internal vs. external budding, as well as variations encountered in sexual stages are discussed. The evolutionary pressures and mechanisms underlying apicomplexan cell division diversification carries relevance across Eukaryota., (Copyright © 2020 Gubbels, Keroack, Dangoudoubiyam, Worliczek, Paul, Bauwens, Elsworth, Engelberg, Howe, Coppens and Duraisingh.)

Cystoisospora (syn. Isospora) suis is a leading cause of diarrheal disease in neonatal piglets. To address the possibility of maternal immunization against C. suis infection six non-naïve pregnant sows were superinfected with 100,000 oocysts 2 weeks ante partum and compared to non-superinfected animals. Their piglets were infected with 1000 oocysts on the third day of life. Clinical and parasitological parameters as well as antibody titers in colostrum/milk and blood of sows and in the blood of piglets were evaluated by IFAT against sporozoites and merozoites from 2 weeks ante partum until the 35th day after birth. For IFAT two different invasive stages of C. suis were used to find possible differences between the immune response against the initially infectious stages (sporozoites) and later occurring asexual developmental stages (merozoites), which might be responsible for persisting/extraintestinal infections. IFN-γ production of PBMC and piglet splenocytes was determined by ELISPOT. Maternal superinfection resulted in increased titers of IgA, IgM and IgG in colostrum and milk as well as in the blood of sows and their piglets. Oocyst shedding and diarrhea were observed in the offspring of both groups, but piglets of superinfected sows showed significantly reduced oocyst shedding and less diarrhea. This protective effect was correlated with increased titers of antibodies, especially IgA, in colostrum, milk and blood serum of sows and piglets, and with the reactivity of splenocytes to parasite antigen. Superinfection of sows ante partum could partially protect piglets against the clinical outcome of experimental infection. Both colostrum and milk contain maternal protective substances as the effect of protection was highly correlated with antibody titers during the first 2 weeks of life. IgA in different substrates may serve as a marker for the level of protection against clinical cystoisosporosis., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Infections of neonatal piglets with Cystoisospora suis are responsible for substantial economic losses in pig production. To investigate kinetics of T-cell populations, which are possibly involved in this infection, lymphocytes from blood, spleen, mesenteric lymph nodes and the jejunal mucosa of infected and noninfected piglets were investigated by flow cytometry and immunohistochemistry at five time points during the acute phase of primary infection. Additionally, mRNA expression levels of pattern recognition receptors and immunomodulatory cytokines in the jejunum were investigated. T-cell receptor-γδ(+) T cells were found to be increased in the gut mucosa 4 days after infection and were most likely involved in the primary local immune response. Five to eleven days later, cytotoxic T cells peaked in this location, which was preceded by an expansion of this lymphocyte population in the mesenteric lymph nodes. In intestines of infected piglets, mRNA expressions of TLR-2, NOD2 and TNF-α were significantly upregulated, suggesting an involvement in parasite recognition, immune response and possibly also in immunopathology. Taken together, this study identifies cellular and molecular players involved in the early immune responses against C. suis, but their precise role in the pathogenesis and control of this neonatal disease requires further investigation., (© 2014 John Wiley & Sons Ltd.)

Cystoisospora suis is the most pathogenic species of coccidia in suckling piglets, affecting them predominantly within their first three weeks of life. The clinical signs of neonatal cystoisosporosis include watery diarrhea and wasting, leading to significant economic losses for the farmer. Since neonatal piglets have an immature immune system, colostral transfer of maternal factors such as immune cells or antibodies is essential for controlling infections at that age. However, the role of C. suis-specific antibodies transferred from the sow to the piglets and possible correlations between antibody levels in the piglets acquired from colostrum with the clinical outcome of disease are currently not understood. To address this issue, 12 non-infected piglets and 14 piglets experimentally infected with C. suis on the third day of life were examined during their first four weeks of life. IgG, IgA, and IgM titers in the blood serum specific for sporozoites and merozoites of C. suis were evaluated, along with oocyst excretion and fecal consistency. Additionally, the antibody content in the colostrum and milk of three mother sows was determined. A transfer of naturally acquired C. suis-specific antibodies from sows to piglets with the colostrum could be demonstrated. Maternal antibodies in piglets' blood sera did not persist for longer than 14-21 days except for IgG which was present in high titers until the end of the study. Within 2-3 weeks after birth the onset of endogenous antibody production was noticed. Titers in blood serum showed a correlation with the severity of diarrhea which was positive for IgG and IgM (possibly due to increased consumption or loss of these antibodies) and negative for IgA. C. suis-specific mucus antibodies isolated from infected and non-infected piglets (n=6/group) on the 28th day of life were present in both groups, showing significantly higher titers of IgA and IgM in infected piglets. Maternally transferred antibodies acquired by natural infections of sows as observed in this study did not provide protection against the clinical manifestation of disease. The level and effect of transferrable maternal factors necessary for protection still need to be elucidated. However, correlations between antibody titers and fecal consistency in the piglets indicate that C. suis-specific antibodies might be useful markers for the expectable clinical severity of cystoisosporosis., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Theileria spp. are intracellular protozoa transmitted by ixodid ticks. T. parva and T. annulata are highly pathogenic and responsible for serious disease in domestic ruminants in tropical and subtropical countries. However, asymptomatic findings of Theileria sp. in wild ungulates lead to the suggestion that wild ruminants play a role as reservoirs for these piroplasms. In a game enclosure in Eastern Austria (Federal county of Burgenland), piroplasms were detected with molecular analysis in blood samples of all 80 examined asymptomatic red deer (Cervus elaphus). Furthermore, piroplasms were detected in four out of 12 questing nymphs of Haemaphysalis concinna. In 32 Ixodes ticks sampled on-site, no Theileria DNA was detected. Sequence analysis identified these samples from both red deer and ticks as Theileria sp. ZS TO4. Our findings indicate that farmed red deer serve as asymptomatic carriers and adapted intermediate hosts of Theileria sp. in Central Europe and H. concinna was identified as a possible vector species of Theileria sp. ZS TO4., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Coccidian parasites are of major importance in animal production, public health and food safety. The most frequently used representative in basic research on this group is Toxoplasma gondii. Although this parasite is well investigated there is no adequate in vitro model for its sexual development available and knowledge on this important life cycle phase is therefore scarce. The use of Isosporasuis, a sister taxon to T. gondii and the causative agent of piglet coccidiosis, could provide a solution for this. In the present study an in vitro model for neonatal porcine coccidiosis in cells representative for the in vivo situation in the piglet gut was developed and evaluated. The parasite development was investigated by light and transmission electron microscopy and optimum culture conditions were evaluated. Intestinal porcine epithelial cells (IPEC-J2) adequately representing the natural host cells supported the development of all endogenous life cycle stages of I. suis, including gametocytes and oocysts. A concentration of 5% fetal calf serum in the culture medium led to highest gametocyte densities on day 12 post infection. Low infection doses (≤1 sporozoite for 100 host cells) were best for oocyst and gametocyte development. The presented system can also be used for immunostaining with established antibodies developed against T. gondii (in our case, anti-TgIMC3 antibodies directed against the inner membrane complex 3). The complete life cycle of I. suis in a cell line representing the natural host cell type and species provides a unique model among coccidian parasites and can be used to address a wide range of topics, especially with regard to the sexual development of coccidia.

Quantification of immunohistochemical results constitutes an important tool in the analysis of cells and tissue that is not readily replaced by other techniques. For reliable quantification, it is essential to consider factors such as tissue fixation and tissue sampling. We report a study on the model of the intestine of Isospora suis-infected piglets, in which we addressed (1) whether the quantity of detectable T cells in the intestinal mucosa is the same in formalin-, HOPE®-, and cryo-conserved material or whether the amounts of T cells at least correlate with one another; and (2) whether single jejunal segments differ in regard to the quantity of mucosal T cells and variability of lymphocyte infiltration. Quantification of T cells in histological sections of different parts of the jejunum of 15-22 day old piglets infected with I. suis was performed using an anti-CD3-antibody and stereological point counting. Area fractions of T-cell profiles per intestinal mucosa profile were higher in cryo-conserved samples than in HOPE®- and formalin-conserved material but no correlation between different fixations could be found. The proximal part of the jejunum contained fewer T cells compared with mid- and end-jejunum. Coefficients of variation did not differ between the intestinal segments. For quantification of T cells in the gut mucosa of piglets infected with I. suis, the cryo-conserved mid jejunum seems most suitable in cases when unbiased sampling of the complete intestine is not feasible. It is generally not possible to compare quantitative results of immunostaining in samples conserved by different methods., (Copyright © 2011 Wiley-Liss, Inc.)

Porcine coccidiosis caused by Isospora suis is one of the leading causes of neonatal diarrhea in suckling piglets. Currently the only registered drug for metaphylaxis is toltrazuril. To evaluate the effect of treatment on piglets from 7 Austrian farms without and 8 Austrian farms with toltrazuril application we examined oocyst excretion (including determination of oocysts per gram of feces; OPG), diarrhea (fecal score FS 1-4 with 3 and 4 being diarrhea), and general health (health score HS 1-4 with 3 and 4 describing poor health). Both groups included farms with different levels of hygiene. Samples from 265 litters without treatment, comprising 1588 individual samples, and 1548 samples from 258 treated litters were taken twice (around the 14th and the 21st day of life, respectively), examined by autofluorescence and, if positive, by McMaster counting. In both groups animals had less diarrhea and lower health scores during the second sampling but the treated piglets were always significantly healthier and had less diarrhea. The percentage of weaned piglets was higher in treated animals although this was not significant (p=0.052). In the first round of sampling 17.8% of the individual samples from untreated piglets were positive for oocysts (with a maximum prevalence on the 12-15th day of life) while in the treated piglets only 0.4% shed oocysts p<0.001). At the second sampling only 2.1% of the untreated animals and none of treated piglets excreted I. suis (p=0.083). Positive animals shed up to 8 × 10(3)OPG. There was an increased risk for infected piglets to develop diarrhea (odds ratio, OR 4.73) and poor health (OR 5.05) in untreated piglets, and poor hygiene without disinfection was identified as a risk factor for poor health (OR 1.90), diarrhea (OR 1.42) and oocyst excretion (OR 1.73). The risk of poor health (OR 2.89) and diarrhea (OR 1.44) was also increased for piglets under poor hygienic conditions receiving toltrazuril, so both metaphylaxis of coccidiosis and good hygiene are necessary to effectively control neonatal diarrhea. The costs of treatment are considerably lower than the estimated financial production losses. Therefore, treatment is recommended for farms where clinical coccidiosis is diagnosed., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Research in osteoporosis, which is a complex systemic disease, demands suitable large animal models. In pigs, most research has been done in growing minipigs, which probably are not ideal models for postmenopausal osteoporosis. Therefore, our aim was to analyze the effects of ovariectomy (OVX) and nutritive calcium shortage on multiparous Large White sows. 32 animals were randomly assigned to 4 groups in a cross design with OVX vs. sham and physiological calcium supplementation (0.75% calcium) vs. dietary calcium shortage (0.3% calcium). The observation period was 10 months with blood sampling every 2 months for hematological, immunological, and biochemical bone marker measurements. At the termination of the experiment, animals were sacrificed. Samples of trabecular bone of distal radius, proximal tibia, and sixth lumbar vertebra were subjected to micro-computed tomography imaging and ashed afterwards. Dual X-ray absorptiometry scans of the proximal femora were performed with prepared bones being placed in a water bath for mimicking soft tissue. Analyses of bone marker and cytokine profile kinetics, distribution of leukocyte subpopulations, and morphometrical and densitometrical analyses showed no evidence of any impact of OVX or calcium shortage. In conclusion, the skeleton of adult sows of a conventional breed is seemingly protected from effects of OVX and calcium shortage., (© Georg Thieme Verlag KG Stuttgart · New York.)

Summary: Highly purified antigen and appropriate controls are essential for antigen-specific immunoassays. In the case of Isospora suis, the causative agent of neonatal porcine coccidiosis, the only current source of antigen is oocysts isolated from faeces. The aim of this study was to develop a procedure for high-grade purification of I. suis oocysts from piglet faeces to obtain both antigen and representative controls suitable for in vitro re-stimulation of lymphocytes. This was achieved by use of filtration, density-gradient centrifugation and fluorescence-activated cell sorting (FACS). The feasibility for immunological studies was demonstrated with IFN-gamma ELISPOT assays after in vitro re-stimulation of lymphocytes from previously infected swine using the obtained antigen. The developed method allowed the production of highly purified antigen and representative controls from faeces with an oocyst recovery rate of 14%. Regarding the application of the obtained material it could be shown that lymphocytes from I. suis-infected pigs react in an antigen-specific manner in terms of an in vitro recall response by the production of IFN-gamma. This demonstrates the suitability of the developed method for the production of antigen and controls for sensitive immunological readout systems. Moreover, the detected specific IFN-gamma response encourages further functional studies on the cellular immune response to I. suis.

Isospora suis, a common intestinal parasite of piglets, causes neonatal porcine coccidiosis, which results in reduced and uneven weaning weights and economic losses in pig production. Nevertheless, there are no detailed studies available on the immune response to I. suis. The aim of this study was to carry out phenotypical characterization of lymphocytes during primary infections on day 3 after birth. Infected and noninfected piglets were investigated between days 7 and 16 after birth. Lymphocytes from the blood, spleen and mesenteric lymph nodes (flow cytometry) and of the jejunal mucosa (immunohistochemistry) were analysed. A decrease in T cells, especially with the phenotype of resting T-helper cells, T-cell receptor-gammadelta-T cells, and regulatory T cells in the blood, spleen and mesenteric lymph nodes was noticeable. An increase in cells with the phenotype of natural killer cells in the spleen of infected animals was found, and the subset of TcR-gammadelta-T cells was strongly increased in the gut mucosa. Our findings suggest an accelerated migration of those cells into the gut. This study provides a strong indication for the involvement of adaptive and innate immune response mechanisms in the primary immune response to I. suis, especially of TcR-gammadelta-T cells as a linkage between innate and adaptive immunity.

Porcine neonatal coccidiosis is caused by the protozoan Isospora suis and affects mainly piglets in the first three weeks of life. High morbidity with diarrhoea and reduced weight gain lead to economic losses, affecting pig-breeding worldwide. Infection causes damage of the mucosal surface in the jejunum and ileum and transient non-haemorrhagic diarrhoea. Secondary infections with other enteric pathogens may lead to increased mortality. Despite its economic and veterinary importance, the immunology of porcine isosporosis is still poorly understood. A striking feature of the infection is the rapidly increasing age resistance prohibiting the development of clinical disease in piglets older than 3-4 weeks irrespective of the immune status. It can be hypothesised that the development of the innate immune system in the first weeks of life and subsequently its interplay with the adaptive immune system is closely related to this phenomenon. Infections with I. suis induce migration of TcR-gammadelta(+) cells to the gut during primary infection and lead to induction of IFN-gamma production by TcR-gammadelta(+) cells and CD4(+) T-helper cells in blood and various lymphoid tissues. Like in other coccidial infections both innate as well as adaptive response mechanisms are activated during infection. They might be both not completely developed in the first weeks of life and therefore leaving a time frame for successful infection.

Data from 13 trials involving 124 suckling piglets experimentally infected with Isospora suis were evaluated for the effects of infection dose and age on the clinical and parasitological outcome of infection in four different models, infections with 1,000 oocysts on the 1(st) day of life (d.o.l.) (model 1; 9 piglets/3 litters), 1,000 oocysts on the 4(th) d.o.l. (model 2; 25 piglets/11 litters), 1,500 oocysts on the 4(th) d.o.l. (model 3; 40 piglets/20 litters) and 10,000 oocysts on the 4(th) d.o.l. (model 4; 50 animals/10 litters). Weights were determined on the day of birth and in weekly intervals. Faecal consistency and quantitative oocysts excretion were evaluated for 2 weeks starting 4 days after infection (d.p.i.). The weight gain depression was most noticeable in model 2 (infection on the 1(st) d.o.l.), where animals only gained 2.08 x their birth weight until the 22(nd) d.o.l., compared to 2.31-2.52 x in the other groups. This correlated with the occurrence of watery diarrhoea which was found in 37 % of the samples in the acute phase (4-11 d.p.i.) in model 2 but only in 12-20 % of the samples in the other models. Median oocyst excretion peaked earlier in the models with higher infection doses but reached the highest values in model 2 (early infection). As in previous studies, this cross-sectional analysis of a larger number of animals confirms the influence of age on the outcome of isosporosis in suckling piglets, stressing the need to control the infection at an early life phase.

A polyphasic study was undertaken to clarify the taxonomic position of endospore-forming strains 433-D9, 433-E17 and 121-X1. BOX-PCR-generated fingerprints indicated that they may be members of a single species. 16S rRNA gene sequence similarity demonstrated that a representative of this group, 433-D9, is affiliated closely with Bacillus arvi DSM 16317(T) (100 %), Bacillus arenosi DSM 16319(T) (99.8 %) and Bacillus neidei NRRL BD-87(T) (97.1 %). Sequence similarities revealed Bacillus pycnus NRRL NRS-1691(T) and several Kurthia species as the next nearest relatives. DNA-DNA hybridization results showed that strain 433-D9 is a member of B. arvi. Detection of l-Lys-d-Asp-based peptidoglycan in strain 433-D9, B. arvi DSM 16317(T) and B. arenosi DSM 16319(T) was in agreement with their close relationship, but differentiated these strains from B. neidei NRRL BD-87(T) and B. pycnus NRRL NRS-1691(T), for which l-Lys-d-Glu was reported. A similar quinone system was detected in strains 433-D9, 433-E17, 121-X1, B. arvi DSM 16317(T), B. arenosi DSM 16319(T) and B. neidei NRRL BD-87(T). This system, unusual for bacilli, consisted of the major compound menaquinone MK-8 (69-80 %) and moderate amounts of MK-7 (19-30 %). This observation was in contrast to the predominance of MK-7 of the closest relative B. pycnus NRRL NRS-1691(T), as also reported for representatives of the closely related non-endospore-forming genus Kurthia. Strains 433-D9, B. arvi DSM 16317(T) and B. arenosi DSM 16319(T) exhibited homogeneous and discriminative polar lipid profiles and fatty acid profiles consisting of major acids i-C(15 : 0) and ai-C(15 : 0) and moderate amounts of i-C(17 : 1)omega10c and i-C(17 : 1) I/ai-C(17 : 1) B that discriminated them from closely related strains such as B. neidei NRRL BD-87(T). On the basis of clear-cut discriminative chemotaxonomic markers, we propose strains 433-D9, 433-E17 and 121-X1, B. arvi DSM 16317(T), B. arenosi DSM 16319(T) and B. neidei NRRL BD-87(T) to be reclassified within a separate genus. For this new taxon, we propose the name Viridibacillus gen. nov., and we propose the reclassification of Bacillus arvi, Bacillus arenosi and Bacillus neidei as Viridibacillus arvi gen. nov., comb. nov. (the type species of Viridibacillus, with the type strain DSM 16317(T) =LMG 22165(T)), Viridibacillus arenosi comb. nov. (type strain DSM 16319(T) =LMG 22166(T)) and Viridibacillus neidei comb. nov. (type strain NRRL BD-87(T) =DSM 15031(T) =JCM 11077(T)).

A set of 20 Mollicutes strains representing different lines of descent, including the type species of the genus Mycoplasma, Mycoplasma mycoides, Acholeplasma laidlawii and a strain of Mesoplasma, were subjected to polar lipid and fatty acid analyses in order to evaluate their suitability for classification purposes within members of this group. Complex polar lipid and fatty acid profiles were detected for each examined strain. All strains contained the polar lipids phosphocholine-6'-alpha-glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (MfGL-I), 1-O-alkyl/alkenyl-2-O-acyl-glycero-3-phosphocholine (MfEL), sphingomyelin (SphM), 1-O-alkyl/alkenyl-glycero-3-phosphocholine (lysoMfEL), the unknown aminophospholipid APL1 and the cholesterol Chol2. A total of 19 strains revealed the presence of phosphatidylethanolamine (PE) and/or phosphatidylglycerol (PG), and the presence of diphosphatidylglycerol (DPG) was detected in 13 strains. The unknown aminolipid AL1 was found in the extracts of 17 strains. Unbranched saturated and unsaturated compounds predominated in the fatty acid profiles. Major fatty acids were usually C16:0, C18:0, C18:1 omega9c and 'Summed feature 5' (C18:2 omega6, 9c/C18:0 anteiso). Our results demonstrated that members of the M. mycoides cluster showed rather homogenous polar lipid and fatty acid profiles. In contrast, each of the other strains was characterized by a unique polar lipid profile and significant quantitative differences in the presence of certain fatty acids. These results indicate that analyses of both polar lipid and fatty acid profiles could be a useful tool for classification of mycoplasmas.

Isospora suis, an intestinal protozoan parasite of swine, is the causative agent of neonatal coccidiosis, a disease with high morbidity in affected pig-breeding units and consequently of high economic importance. Infection leads to damage of the mucosal surface in the jejunum and ileum and to non-haemorrhagic diarrhoea. As a result, weight gain of piglets is reduced and secondary infections with other enteric pathogens may lead to increased mortality. Despite its economic and veterinary importance, host-parasite interactions are still poorly understood. To examine these interactions experimental infection models are established using outbred piglets infected with defined numbers of parasites on different days of life. This review discusses the life cycle of Isospora suis and the clinical and parasitological characteristics of porcine neonatal coccidiosis including pathology, and compare the different experimental infection models and the tools for studying Isospora suis in vitro. Moreover, it summarises findings about natural age resistance of pigs against infections with Isospora suis, our current knowledge about immune response to other coccidial infections, e.g. with Eimeria spp. in different hosts, and gives a short overview on peculiarities of the porcine immune system and its development in young animals which may play a role in porcine coccidiosis.

A Gram-positive, aerobic, rod-shaped, motile, endospore-forming bacterium was isolated from pasteurized milk from Bavaria, Germany. 16S rRNA gene sequence similarities indicated that strain WSBC 24001(T) was most closely related to Virgibacillus species (95.3-96.1 %), Oceanobacillus species (95.6-95.7 %), Bacillus firmus IAM 12464(T) (95.5 %) and Bacillus niacini IFO 15566(T) (95.2 %). However, strain WSBC 24001(T) showed the highest level of sequence similarity to an unnamed strain, MB-9(T) (97.6 %), which was isolated from coastal surface sediments in California. Hence, this strain was included in our study. The genomic DNA G + C contents of strains WSBC 24001(T) and MB-9(T) were 36.4 mol and 40.8 mol%, respectively. The major respiratory quinone of both strains was menaquinone MK-7 and the peptidoglycan type was A4beta (L-orn<--D-Asp). The polar lipid profiles of these strains contained a predominance of diphosphatidylglycerol and moderate to minor amounts of phosphatidylglycerol, an unknown phospholipid and an unknown aminophospholipid. However, strain WSBC 24001(T) could be distinguished from strain MB-9(T) by the presence of an unknown lipid. The fatty acid profiles of the two strains comprised mainly iso- and anteiso-branched acids, but showed some significant quantitative differences in the amounts of certain acids. The DNA-DNA relatedness value (15.5 %) clearly demonstrated that strains WSBC 24001(T) and MB-9(T) are representatives of two different species. On the basis of their phylogenetic position and morphological, physiological and chemotaxonomic properties, a novel genus is proposed, Ornithinibacillus gen. nov., with two novel species, the type species Ornithinibacillus bavariensis sp. nov. (type strain WSBC 24001(T) = DSM 15681(T) = CCM 7096(T)) and Ornithinibacillus californiensis sp. nov. (type strain MB-9(T) = DSM 16628(T) = CCM 7237(T)).