Medicine and Health Sciences Commons^™

Repeated Stressors In Adulthood Increase The Rate Of Biological Ageing, Michaela Hau, Mark F. Haussmann, Timothy J. Greives, Christa Matlack, David Costantini, Michael Quetting, James S. Adelman, Ana C. Miranda, Jesko Partecke

James S. Adelman

Individuals of the same age can differ substantially in the degree to which they have accumulated tissue damage, akin to bodily wear and tear, from past experiences. This accumulated tissue damage reflects the individual’s biological age and may better predict physiological and behavioural performance than the individual‘s chronological age. However, at present it remains unclear how to reliably assess biological age in individual wild vertebrates. We exposed hand-raised adult Eurasian blackbirds (Turdus merula) to a combination of repeated immune and disturbance stressors for over one year to determine the effects of chronic stress on potential biomarkers of biological ageing including …

Intraocular Pressure Changes In Equine Athletes During Endurance Competitions, Rachel A. Allbaugh, Susan M. Keil, Zhining Ou, Nora M. Bello

Rachel A. Allbaugh

Objective To assess intraocular pressure (IOP) in conditioned equine athletes and document changes with exercise. A secondary objective was to assess associations between IOP and heart rate, as well as with other subjective physical parameters.

Sample Population Horses were evaluated during 50 mile endurance ride competitions. Data were collected on 69 horses during 5 different competitions at 3 different locations with 59 horses ridden once, 9 horses ridden in two competitions, and 1 horse ridden in three competitions for a total of 80 horse-ride combinations.

Procedures Intraocular pressure was measured using a TonoVet® tonometer in both eyes of each horse …

Linking Social Behavior And Stress Physiology In Feral Mares (Equus Caballus): Group Transfers Elevate Fecal Cortisol Levels, Cassandra M.V. Nuñez, James S. Adelman, Jessica Smith, Laurence Gesquiere, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Feral horses (Equus caballus) have a complex social structure, the stability of which is important to their overall health. Behavioral and demographic research has shown that decreases in group (or band) stability reduce female fitness, but the potential effects on the physiological stress response have not been demonstrated. To fully understand how band stability affects group-member fitness, we need to understand not only behavioral and demographic, but also physiological consequences of decreases to that stability. We studied group changes in feral mares (an activity that induces instability, including both male and female aggression) on Shackleford Banks, NC. We found that …

Linking Social Environment And Stress Physiology In Feral Mares (Equus Caballus): Group Transfers Elevate Fecal Cortisol Levels, Cassandra M.V. Nuñez, James S. Adelman, Jessica Smith, Laurence R. Gesquiere, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Feral horses (Equus caballus) have a complex social structure, the stability of which is important to their overall health. Behavioral and demographic research has shown that decreases in group (or band) stability reduce female fitness, but the potential effects on the physiological stress response have not been demonstrated. To fully understand how band stability affects group-member fitness, we need to understand not only behavioral and demographic, but also physiological consequences of decreases to that stability. We studied group changes in feral mares (an activity that induces instability, including both male and female aggression) on Shackleford Banks, NC. We found that …

A Free-Ranging, Feral Mare Equus Caballus Affords Similar Maternal Care To Her Genetic And Adopted Offspring, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Adoption of nongenetic offspring occurs in a variety of species but is rare in equids. We report a case of adoption by a free-ranging, feral mare Equus caballus and compare the maternal care received by her genetic offspring (born 1995) to that of her adopted offspring (born 1996) for the first 30 weeks of development. We compare five measures of care: (1) total time spent suckling, (2) mare aggression during suckling, (3) number of mare-terminated suckling bouts, (4) contact maintenance, and (5) mare-foal distance. For most behaviors, we detected no difference in the mare’s treatment of the two foals; however, …

The Genome And Developmental Transcriptome Of The Strongylid Nematode Haemonchus Contortus, Erich M. Schwarz, Pasi K. Korhonen, Bronwyn E. Campbell, Neil D. Young, Aaron R. Jex, Abdul Jabbar, Ross S. Hall, Alinda Mondal, Adina C. Howe, Jason Pell, Andreas Hofmann, Peter R. Boag, Xing-Quan Zhu, T. Ryan Gregory, Alex Loukas, Brian A. Williams, Igor Antoshechkin, C. Titus Brown, Paul W. Sternberg, Robin B. Gasser

Adina Howe

Background The barber's pole worm, Haemonchus contortus, is one of the most economically important parasites of small ruminants worldwide. Although this parasite can be controlled using anthelmintic drugs, resistance against most drugs in common use has become a widespread problem. We provide a draft of the genome and the transcriptomes of all key developmental stages of H. contortus to support biological and biotechnological research areas of this and related parasites. Results The draft genome of H. contortus is 320 Mb in size and encodes 23,610 protein-coding genes. On a fundamental level, we elucidate transcriptional alterations taking place throughout the life …

House Finch Populations Differ In Early Inflammatory Signaling And Pathogen Tolerance At The Peak Of Mycoplasma Gallisepticum Infection, James S. Adelman, Laila Kirkpatrick, Jessica L. Grodio, Dana M. Hawley

James S. Adelman

Host individuals and populations often vary in their responses to infection, with direct consequences for pathogen spread and evolution. While considerable work has focused on the mechanisms underlying differences in resistance—the ability to kill pathogens— we know little about the mechanisms underlying tolerance— the ability to minimize fitness losses per unit pathogen. Here, we examine patterns and mechanisms of tolerance between two populations of house finches (Haemorhous [formerly Carpodacus] mexicanus) with different histories with the bacterial pathogen Mycoplasma gallisepticum (MG). After infection in a common environment, we assessed two metrics of pathology, mass loss and eye lesion severity, as proxies …

Does Immunocontraception In Feral Horses (Equus Caballus) Extend Reproductive Cycling Beyond The Normal Breeding Season?, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP’s effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births from 45 mares; post-contraception, n = 97 births from 46 mares). Gestation lasts …

Immunocontraception In Wild Horses (Equus Caballus) Extends Reproductive Cycling Beyond The Normal Breeding Season, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP's effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births from 45 mares; post-contraception, n = 97 births from 46 mares). Gestation lasts …

Protection Of Retinal Cells From Ischemia By A Novel Gap Junction Inhibitor, Satyabrata Das, Dingo Lin, Snehalata Jena, Aibin Shi, Srinivas Battina, Duy H. Hua, Rachel A. Allbaugh, Dolores J. Takemoto

Rachel A. Allbaugh

Retinal cells which become ischemic will pass apoptotic signal to adjacent cells, resulting in the spread of damage. This occurs through open gap junctions. A class of novel drugs, based on primaquine (PQ), was tested for binding to connexin 43 using simulated docking studies. A novel drug has been synthesized and tested for inhibition of gap junction activity using R28 neuro-retinal cells in culture. Four drugs were initially compared to mefloquine, a known gap junction inhibitor. The drug with optimal inhibitory activity, PQ1, was tested for inhibition and was found to inhibit dye transfer by 70% at 10 μM. Retinal …

Behavioral Effects Of Contraception Management: The Use Of Porcine Zona Pellucida On Wild Horses, Cassandra M.V. Nuñez

Cassandra M.V. Nuñez

The advent of immunocontraception with porcine zona pellucida (PZP) has all but revolutionized wild horse management, providing a more humane method of population control than earlier strategies. Early studies on Assateague Island National Seashore have described it as an ideal form of fertility control in that it reduces the chance of conception to below 10%, can be delivered remotely, is reversible (after short-term use), lacks debilitating physiological side effects, cannot pass through the food chain, and shows minimal effects on social behaviors. However, recent research in other populations has revealed behavioral and physiological side effects of long-term PZP use. These …

Keratinizing Ameloblastoma In A 9-Month-Old Llama (Lama Glama), Karyn E. Bird, Jill E. Parker, Claire B. Andreasen, Barbara J. Watrous, Jerry R. Heidel

Claire B. Andreasen

A 9-month-old male llama (Lama glama) was presented because of a rapidly growing mass on the right side of the face. Radiographs revealed a marked expansion of the right caudal face region with bone lysis involving the maxilla and the nasal, lacrimal, zygomatic, and palatine bones. Cytologically, the mass consisted of atypical round to polygonal cells with round nuclei and basophilic cytoplasms that formed acini and rows. Histologically, the mass consisted of anastomosing cords and sheets of neoplastic odontogenic epithelial cells embedded in a loose fibrovascular connective tissue. Single layers of peripheral, polarized, palisading, columnar epithelial cells were seen at …

Prediction Of Chicken Embryo Lethality With The Avian Escherichia Coli Traits Complement Resistance, Colicin V Production, And Presence Of The Increased Serum Survival Gene Cluster (Iss), Penelope S. Gibbs, John J. Maurer, Lisa K. Nolan, Richard E. Wooley

Lisa K. Nolan

Differentiating between virulent and avirulent avian Escherichia coli isolates continues to be a problem for poultry diagnostic laboratories and the study of colibacillosis in poultry. The ability of a laboratory to conduct one simple test that correlates with virulence would simplify studies in these areas; however, previous studies have not enabled researchers to establish such a test. In this study, the occurrence of certain phenotypic and genotypic traits purported to contribute to avian E. coli virulence in 20 avian E. coli isolates was correlated with the results of embryo challenge studies. This analysis was undertaken in an effort to determine …

Characterization Of Integron Mediated Antimicrobial Resistance In Salmonella Isolated From Diseased Swine, David G. White, Shaohua Zhao, Patrick F. Mcdermott, Sherry Ayers, Sharon Friedman, Julie Sherwood, Missy Breider-Foley, Lisa K. Nolan

Lisa K. Nolan

Forty-two Salmonella isolates obtained from diseased swine were genetically characterized for the presence of specific antimicrobial resistance mechanisms. Twenty of these isolates were characterized as S. Typhimurium DT104 strains. Pulsed-field gel electrophoresis was used to determine genetic relatedness and revealed 20 distinct genetic patterns among the 42 isolates. However, all DT104 isolates fell within 2 closely related genetic clusters. Other Salmonella isolates were genetically grouped together according to serotype. All DT104 isolates displayed the penta-resistance phenotype to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline. Resistance to sulfamethoxazole, tetracycline, streptomycin, kanamycin, and ampicillin was most common among the non-DT104 Salmonella isolates. All …

Monoclonal Antibodies To Avian Escherichia Coli Iss, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Thomas R. Gustad, Erick D. Handegard, Michael Robinson, Lisa K. Nolan

Lisa K. Nolan

Escherichia coli infections are a major problem for the poultry industry in the United States. Yet, the virulence mechanisms operative in avian E. coli are poorly understood. In the present studies, monoclonal antibodies (MAbs) have been generated that may facilitate study of the pathogenesis of avian colibacillosis. These MAbs are directed against the Iss protein because results from our laboratory have shown that the possession of iss DNA sequences is strongly correlated with the E. coli implicated in avian colibacillosis. As part of an overall effort to explore the role of iss/Iss in colibacillosis pathogenesis, Iss protein has been purified, …

Complement Resistance, As Determined By Viable Count And Flow Cytometric Methods, And Its Association With The Presence Of Iss And The Virulence Of Avian Escherichia Coli, Lisa K. Nolan, Catherine W. Giddings, Shelley M. Horne, Curt Doetkott, Penelope S. Gibbs, Richard E. Wooley, Steven L. Foley

Lisa K. Nolan

Previous work in our labs has shown that avian Escherichia coli virulence is correlated with resistance to complement. Also, our studies have revealed that the presence of the increased serum survival gene (iss), known to contribute to the complement resistance and virulence of mammalian E. coli, may predict the virulent nature of an avian E. coli isolate. This relationship warrants further research, but further clarification of the relationship among virulence, complement resistance, and iss sequences requires use of complement susceptibility assays. Such assays, unfortunately, are labor-intensive, expensive, and difficult to perform. In the present study, the results of two complement …

Location Of Increased Serum Survival Gene And Selected Virulence Traits On A Conjugative R Plasmid In An Avian Escherichia Coli Isolate, Timothy J. Johnson, Catherine W. Giddings, Shelley M. Horne, Penelope S. Gibbs, Richard E. Wooley, Jerod Skyberg, Pam Olah, Ronda Kercher, Julie S. Sherwood, Steven L. Foley, Lisa K. Nolan

Lisa K. Nolan

Avian colibacillosis is a costly disease for the poultry industry. The mechanisms of virulence employed by the etiologic agent of this disease remain ill defined. However, accumulated evidence suggests that complement resistance and the presence of the increased serum survival gene (iss) in an avian Escherichia coli isolate may be indicative of its ability to cause disease. This association of iss with the E. coli implicated in avian disease may mean that iss and/or, perhaps, the genes associated with it are important contributors to avian E. coli virulence. For this reason, we have begun a search for iss's location in …

Virulence Factors Of Escherichia Coli From Cellulitis Or Colisepticemia Lesions In Chickens, J. S. Jeffrey, Lisa K. Nolan, K. H. Tonooka, S. Wolfe, C. W. Giddings, S. M. Horne, S. L. Foley, A. M. Lynne, J. O. Ebert, L. M. Elijah, G. Bjorklund, S. J. Pfaff-Mcdonough, R. S. Singer, C. Doetkott

Lisa K. Nolan

This study was designed to compare virulence factors of cellulitis-derived Escherichia coli to colisepticemic E. coli in order to clarify whether E. coli associated with cellulitis comprise a unique subset of pathogenic E. coli. Isolates were tested for serotype, capsule, aerobactin production, colicin production, the presence of the iss gene, and serum resistance. Untypable isolates made up the greatest percentage of each group. Serotypes O2 and O78 were the most commonly identified among both groups of isolates. No statistical differences in the distribution of aerobactin or colicin production, capsule, or iss gene were observed between groups. Cluster analysis showed that …

Cloning And Sequencing Of The Iss Gene From A Virulent Avian Escherichia Coli, Shelley M. Horne, Samantha J. Pfaff-Mcdonough, Catherine W. Giddings, Lisa K. Nolan

Lisa K. Nolan

Control of colibacillosis is important to the poultry industry. We have found that the presence of a gene for increased serum survival, iss, is strongly correlated with Escherichia coli isolated from birds with colibacillosis. Therefore, the iss gene and its protein product, Iss, are potential targets for detection and control of avian colibacillosis. The iss gene was amplified from a virulent avian E. coli isolate and sequenced. The sequences of the gene and the predicted protein product were compared with those of iss from a human E. coli isolate and lambda bor. The iss gene from the avian E. coli …

Iss From A Virulent Avian Escherichia Coli, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Michael Robinson, Lisa K. Nolan

Lisa K. Nolan

No single characteristic of virulent avian Escherichia coli has been identified that can be exploited in colibacillosis detection protocols. Research in our lab suggests a strong association between the presence of an iss DNA sequence with an isolate's disease-causing ability. The study presented here focuses on the techniques used in the expression, purification, and characterization of avian E. coli Iss protein. In brief, iss was cloned into an expression vector, the construct was transformed into a protease-deficient E. coli, and expression was induced. The protein was expressed as a glutathione-S-transferase (GST) fusion and purified by affinity chromatography. The GST portion …

Complement Resistance-Related Traits Among Escherichia Coli Isolates From Apparently Healthy Birds And Birds With Colibacillosis, Samantha J. Pfaff-Mcdonough, Shelley M. Horne, Catherine W. Giddings, Jessica O. Ebert, Curt Doetkott, M. Herbert Smith, Lisa K. Nolan

Lisa K. Nolan

In this study, 294 Escherichia coli isolates from birds with colibacillosis were collected from disease outbreaks throughout the United States and were compared with 75 fecal E. coli isolates of apparently healthy chickens by their possession of several purported virulence genes, resistance to rough-lipopolysaccharide-specific bacteriophages (rLPSr), and elaboration of capsule. Traits were selected for study on the basis of their association with complement resistance. The genes targeted in this study included those encoding colicin V (cvaC) and the outer membrane proteins TraT (traT), OmpA (ompA), and Iss (iss). No significant differences were found between the two groups of isolates in …

Enhanced Adhesion Of Pasteurella Multocida To Cultured Turkey Peripheral Blood Monocytes, Ingrid M. Pruimbroom, Richard B. Rimler, Mark R. Ackermann

Mark R. Ackermann

Capsular hyaluronic acid (HA) mediates adhesion of serogroup A strains of Pasteurella multocida to elicited turkey air sac macrophages (TASM). In contrast, freshly isolated turkey peripheral blood monocytes (TPBM) do not bind serogroup A strains. Following culture of TPBM for 6 days in chamber slides, adhesion of the bacteria to TPBM increased gradually. Incubation in chamber slides coated with entactin-collagen IV-laminin (ECL) attachment matrix or exposure to phorbol myristate acetate (PMA) further enhanced the adhesion ofP. multocida to TPBM. Addition of HA, but not Arg-Gly-Asp peptide, to TPBM culture inhibited bacterial adherence similarly to the inhibition previously reported for TASM. …

Normal Reference Intervals And The Effects Of Time And Feeding On Serum Bile Acid Concentrations In Llamas, Claire B. Andreasen, Erwin G. Pearson, Brad B. Smith, Terry C. Gerros, Duane Lassen

Claire B. Andreasen

Fifty clinically healthy llamas, 0.5–13 years of age (22 intact males, 10 neutered males, 18 females), with no biochemical evidence of liver disease or hematologic abnormalities, were selected to establish serum bile acid reference intervals. Serum samples submitted to the clinical pathology laboratory were analyzed using a colorimetric enzymatic assay to establish bile acid reference intervals. A nonparametric distribution of llama bile acid concentrations was 1–23 mmol/liter for llamas .1 year of age and 10–44 mmol/liter for llamas #1 year of age. A significant difference was found between these 2 age groups. No correlation was detected between gender and bile …

Further Characterization Of A Complement-Sensitive Mutant Of A Virulent Avian Escherichia Coli Isolate, Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, Tom Gustad, Shelley M. Horne, Catherine W. Giddings

Lisa K. Nolan

An attempt was made to characterize the mechanism of complement resistance operating in a virulent avian Escherichia coli isolate. Using flow cytometry to detect antibody to C3, we found that there was significantly more antibody bound to a complement-sensitive mutant of this wild type than to the parent organism, suggesting that more C3 subunits were bound to the wild type. Neither the wild type nor the mutant degraded C3. Further, the mutant was phagocytosed to a significantly greater degree than the wild type by cultured phagocytes in the presence of C5-deficient serum. These data suggest that the wild type is …

A Highly Adherent Phenotype Associated With Virulent Bvg+-Phase Swine Isolates Of Bordetella Bronchiseptica Grown Under Modulating Conditions, Karen B. Register, Mark R. Ackermann

Mark R. Ackermann

The ability of Bvg(-)-phase and Bvg(+)-phase Bordetella bronchiseptica swine isolates, grown under modulating or nonmodulating conditions, to adhere to swine ciliated nasal epithelial cells was determined. When virulent strains were cultivated at 37 degrees C in the Bvg+ phase, numerous adherent bacteria (approximately eight per cell, depending on the strain used) were observed. However, when such strains were grown under modulating conditions (23 degrees C), a significant increase in the level of attachment was seen, suggesting that B. bronchiseptica produces a Bvg-repressed adhesin under these conditions. bvg mutant strains, including an isogenic bvgS mutant, adhered minimally. Western blots indicated that …

Effects Of Pasteurella Multocida Toxin On Porcine Bone Marrow Cell Differentiation Into Osteoclasts And Osteoblasts, S. M. Gwaltney, R. J. S. Galvin, K. B. Register, R. B. Rimler, Mark R. Ackermann

Mark R. Ackermann

The effect of Pasteurella multocida toxin (PMT) on porcine osteoclast and osteoblast differentiation was studied using in vitro cell culture systems. When grown in the presence of Vitamin D3, isolated porcine bone marrow cells formed multinucleated cells with features characteristic of osteoclasts. Exposure of bone marrow cells to Vitamin D3 and PMT during growth resulted in formation of increased numbers and earlier appearance of osteoclasts compared to controls. Ultrafiltered medium from PMT-treated cells likewise increased osteoclast numbers, suggesting that a soluble mediator may be involved in the action of PMT. When cell cultures were treated with fluorescein-labeled PMT, fluorescence was …

Decreased Intracellular Survival Of An Fkpa Mutant Of Salmonella Typhimurium Copenhagen, Shelley M. Horne, Theodore J. Kottom, Lisa K. Nolan, Kevin D. Young

Lisa K. Nolan

The fkpA gene of Salmonella typhimurium encodes a protein similar to the macrophage infectivity potentiator (Mip) proteins of Legionella pneumophila and Chlamydia trachomatis. Because Mip proteins enhance the ability of these intracellular pathogens to survive within macrophages and epithelial cells, we tested whether the product of the fkpA gene would have the same effect on the intracellular growth of a virulent strain of S. typhimurium. By a series of P22 transductions, the fkpA gene of S. typhimurium Copenhagen was replaced with the inactive fkpA1::omega-Cm gene from Escherichia coli, creating the mutant S. typhimurium KY32H1. The Copenhagen and KY32H1 strains were …

A Porcine Model For The Evaluation Of Virulence Of Bordetella Bronchiseptica, Mark R. Ackermann, K. B. Register, C. Gentry-Weeks, S. M. Gwaltney, T. Magyar

Mark R. Ackermann

Studies of virulence factors of Bordetella bronchiseptica require a suitable system. Such a system was devised in colostrum-deprived, caesarean-derived pigs, aged 7 d. In two different experiments, pigs (n=11) were inoculated intranasally with 106 colony-forming units of the virulent strain 4609. In the same way, further pigs (n=11) were inoculated with a strain (B133) of unknown virulence. No significant differences between 4609 and B133 colonization were seen. However, colonization of the turbinates was significantly higher than that of the trachea, lung and tonsil, and a significantly higher degree of colonization was present at 11 d post-inoculation (PI) than at 15 …

Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill

Lisa K. Nolan

The plasmid DNA of 30 Escherichia coli isolates from chickens was extracted and examined using techniques designed to isolate large plasmids. This plasmid DNA was examined for the presence of certain known virulence-related genes including cvaC, tra7 and some aerobactin-related sequences. Seventeen of the 30 isolates contained from one to four plasmids greater than 50 kb in size. Eleven of these 17 strains possessed plasmids greater than 100 kb in size. Therefore, E. coli isolates of chickens frequently contain large plasmids, and many of these plasmids are likely to contain virulence related sequences.

Passage Of Cd18- And Cd18+ Bovine Neutrophils Into Pulmonary Alveoli During Acute Pasteurella Haemolytica Pneumonia, Mark R. Ackermann, M. E. Kehrli Jr., K. A. Brogden

Mark R. Ackermann

CD18 is a subunit for three β2 integrin molecules (Mac-1, p150, 95, LFA-1), which are expressed on the plasma membrane of neutrophils. These molecules mediate passage of neutrophils into sites of infection. In children and animals that lack CD18 expression, neutrophil infiltration is impaired in most tissues. However, in lung, CD18-neutrophils have been identified in the airway spaces during spontaneous episodes of pneumonia. To determine whether CD18 is vital for passage through the pulmonary alveolar wall, lung lobes of cattle with neutrophils that were deficient in CD18 expression (CD18-) and cattle with normal CD18 expression (CD18+) were inoculated with Pasteurella …