scholarly journals Bacterial keratitis: similar bacterial and clinical outcomes in female versus male New Zealand White rabbits infected with Serratia marcescens

2021 ◽  
Author(s):  
Eric G Romanowski ◽  
Sanya Yadav ◽  
Nicholas A Stella ◽  
Kathleen A Yates ◽  
John E Romanowski ◽  
...  
Keyword(s):  
New Zealand ◽  
Serratia Marcescens ◽  
Viral Infections ◽  
Zealand White Rabbit ◽  
Gram Negative Bacteria ◽  
Bacterial Keratitis ◽  
Gram Negative ◽  
Single Sex ◽  
New Zealand White Rabbits ◽  
Microbiological Parameters

Females and males respond differently to a number of systemic viral infections. Differences between females and males with respect to the severity of keratitis caused by Gram-negative bacteria such as Serratia marcescens are less well established. In this study we injected female and male New Zealand White rabbit corneas with a keratitis isolate of S. marcescens and evaluated the eyes after 48 hours for a number of clinical and microbiological parameters. No statistical differences in bacterial burden and corneal scores were recorded between female and male rabbits although there was a non-significant trend toward a higher frequency of female rabbits demonstrating hypopyons. This data suggests that for experimental bacterial keratitis studies involving Gram-negative rods, a single sex or mixed group of rabbit is sufficient for evaluating pathology and bacterial burdens. This will reduce the number of animals used for subsequent studies.

scholarly journals An Investigation of the Relationship between Cyniclomyces guttulatus and Rabbit Diarrhoea

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 880
Author(s):  
Tuanyuan Shi ◽  
Xinlei Yan ◽  
Hongchao Sun ◽  
Yuan Fu ◽  
Lili Hao ◽  
...  
Keyword(s):  
New Zealand ◽  
Body Weight Gain ◽  
Animal Experiments ◽  
Zealand White Rabbit ◽  
Opportunistic Pathogen ◽  
Large Numbers ◽  
New Zealand White Rabbits ◽  
Positive Rate ◽  
Relationship Of ◽  
The Relationship

Cyniclomyces guttulatus is usually recognised as an inhabitant of the gastrointestinal (GI) tract in rabbits. However, large numbers of C. guttulatus are often detected in the faeces of diarrhoeic rabbits. The relationship of C. guttulatus with rabbit diarrhoea needs to be clearly identified. In this study, a C. guttulatus Zhejiang strain was isolated from a New Zealand White rabbit with severe diarrhoea and then inoculated into SPF New Zealand white rabbits alone or co-inoculated with Eimeriaintestinalis, another kind of pathogen in rabbits. Our results showed that the optimal culture medium pH and temperature for this yeast were pH 4.5 and 40–42 °C, respectively. The sequence lengths of the 18S and 26S ribosomal DNA fragments were 1559 bp and 632 bp, respectively, and showed 99.8% homology with the 18S ribosomal sequence of the NRRL Y-17561 isolate from dogs and 100% homology with the 26S ribosomal sequence of DPA-CGR1 and CGDPA-GP1 isolates from rabbits and guinea pigs, respectively. In animal experiments, the C. guttulatus Zhejiang strain was not pathogenic to healthy rabbits, even when 1 × 108 vegetative cells were used per rabbit. Surprisingly, rabbits inoculated with yeast showed a slightly better body weight gain and higher food intake. However, SPF rabbits co-inoculated with C. guttulatus and E. intestinalis developed more severe coccidiosis than rabbits inoculated with C. guttulatus or E. intestinalis alone. In addition, we surveyed the prevalence of C. guttulatus in rabbits and found that the positive rate was 83% in Zhejiang Province. In summary, the results indicated that C. guttulatus alone is not pathogenic to healthy rabbits, although might be an opportunistic pathogen when the digestive tract is damaged by other pathogens, such as coccidia.

scholarly journals The effect of age, anatomical site and bone structure on osteogenesis in New Zealand White rabbit

2015 ◽  
Vol 88 (2) ◽  
Author(s):  
Francesca Ravanetti ◽  
Edoardo Scarpa ◽  
Vittorio Farina ◽  
Marco Zedda ◽  
Carlo Galli ◽  
...  
Keyword(s):  
New Zealand ◽  
Bone Structure ◽  
Skeletal Maturity ◽  
Zealand White Rabbit ◽  
Anatomical Site ◽  
Bone Implants ◽  
New Zealand White Rabbits ◽  
Preclinical Trials ◽  
Parietal Bones

Among animal models, rabbits are widely used in medical research, as they fill the gap between smaller models, commonly employed in basic science, and larger ones, which are better suited for preclinical trials. Given their rapid growth, rabbits provide a valuable system for the evaluation of bone implants for tissue regeneration. By means of a histomorphometric analysis, here we quantified the mineral apposition rates (MARs) in osteonic, periosteum and endosteum osteogenic fronts, of skeletal elements within femur, tibia, radius, ulna, frontal and parietal bones in New Zealand White rabbits aged 6, 7 and 8 months. Our hypothesis is that the MAR varies according to the skeletal maturity of the animal, and also within the skeletal elements and the osteogenic fronts considered. In the present study we show that the MAR in both femur and tibia is significantly higher than in ulna and radius. We also demonstrate that the MAR in parietal bones is significantly higher compared to the MAR of both frontal and forelimb bones. Contrary to what was expected, the MARs of all the skeletal elements considered were not decreased following full skeletal maturity. Finally, the MAR of the osteonic-osteogenic front is the lowest in all of the skeletal elements considered. In conclusion, these results provide new important insights for the evaluation of bone implants, casting a light on the role of both age and osteogenic fronts on the bone MAR, and providing valuable information on the physiological bone turnover in New Zealand White rabbits.

scholarly journals Optimization of Agitation Rate in Bioreactor Increases Chitinase Activity of Serratia marcescens PT6

2020 ◽  
Vol 147 ◽  
pp. 03019
Author(s):  
Amara Faiz Wriahusna ◽  
Niswah Umhudloh Dzakiyya ◽  
Indun Dewi Puspita ◽  
Sri Pudjiraharti
Keyword(s):  
Serratia Marcescens ◽  
Bacterial Growth ◽  
Agar Medium ◽  
Chitinase Activity ◽  
Colloidal Chitin ◽  
Gram Negative Bacteria ◽  
Agitation Rate ◽  
Anova Analysis ◽  
Gram Negative ◽  
Shrimp Pond

Serratia marcescens PT6 is a Gram-negative bacteria isolated from shrimp pond sediment that capable of producing chitinase. This study aimed to observe the effect of agitation rate on growth and chitinase activity of S. marcescens PT-6 in a bioreactor. The production of chitinase was done in 1.5 l bioreactor using colloidal chitin broth at the condition of pH 7, the temperature of 30°C, aeration of 0.04 vvm, and variation of agitation rate (200, 350, 500 rpm). Bacterial growth was measured by colonies counting in agar medium, while chitinase activity was measured by means of colorimetric every day for four days incubation. The results of ANOVA analysis show that the agitation rate had no effect on bacterial growth, but a significant effect (P<0.05) was observed on chitinase activity. The highest growth and chitinase activity were obtained at 200 rpm, with the highest chitinase activity of 0.006 ± 0.001 U/ml was at day-2. This study implies that the optimized agitation rate in the bioreactor increased the chitinase activity produced by S. marcescens PT-6.

scholarly journals A Genetic Evaluation System for New Zealand White Rabbit Germplasm Resources Based on SSR Markers

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1258
Author(s):  
Jiali Li ◽  
Bin Zhao ◽  
Yang Chen ◽  
Bohao Zhao ◽  
Naisu Yang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
New Zealand ◽  
Evaluation System ◽  
Zealand White Rabbit ◽  
Genetic Evaluation ◽  
Germplasm Resources ◽  
Polymorphic Loci ◽  
Marker Combination ◽  
New Zealand White Rabbits ◽  
Two Generations

At present, there is an abundance of quality domestic rabbit breeds in China. However, due to the lack of technical standards for the genetic evaluation of rabbit germplasm resources, there have been a number of problems, such as poor breed conservation. By studying the genetic diversity of 130 New Zealand white rabbits (regardless of generation), we obtained the best simple sequence repeat (SSR) marker combination. We found that, when using microsatellite markers for the effective genetic evaluation of domestic rabbits, the number of records should be greater than 60 and the marker number more than 22. Through the comparative analysis of 30 combinations of 22 markers, the optimal combination of 22 markers was determined, and the 22 SSR polymorphic loci were distributed on different chromosomes. We performed a genetic analysis of 200 New Zealand white rabbits corresponding to two generations, using the best SSR polymorphic loci combination. There were no significant differences in the genetic diversity parameters between the two generations of rabbits (p > 0.05), indicating that the characteristics of this excellent rabbit germplasm have been effectively preserved. At the same time, we verified that the established method can be used to evaluate the breed conservation of rabbit germplasm resources.

scholarly journals Morphometry of megakaryocytes in the liver of New Zealand White rabbits during intrauterine and postnatal development

2002 ◽  
Vol 32 (6) ◽  
pp. 1011-1017
Author(s):  
Maria Rita Pacheco ◽  
Nilson Ferreira ◽  
Válder Rodrigues Melo ◽  
Silvana Martinez Baraldi-Artoni ◽  
Antonio Marcos Orsi ◽  
...  
Keyword(s):  
New Zealand ◽  
Shape Factor ◽  
Zealand White Rabbit ◽  
Postnatal Period ◽  
Maximum Diameter ◽  
Postnatal Life ◽  
Minimum Diameter ◽  
Intrauterine Life ◽  
New Zealand White Rabbit ◽  
New Zealand White Rabbits

The hepatic megakaryocytic cells of New Zealand White rabbit in the intrauterine phase and in the immediate postnatal period were studied. Statistical analysis of the data concerning the cytoplasm and nucleus of those cells, i.e., area, perimeter, maximum diameter, minimum diameter, volume and shape factor, presented significant differences (p<0.01) for F values concerning the life phases studied on15th, 22nd and 29th day of intrauterine life and 10th day of postnatal life, and for F values for animal within each phase. The Tukey’s test showed that most of the parameters studied in the cytoplasm and nucleus of these megakaryocytic cells presented the lowest values on the 15th day of intrauterine life and the highest on the 22nd day of the same phase.

scholarly journals Functional and structural characterization of Serratia marcescens ExbB: determinants of the interaction with HasB/TonB

2021 ◽  
Author(s):  
Valérie Biou ◽  
Ricardo Jorge D Adaixo ◽  
Mohamed Chami ◽  
Pierre-Damien Coureux ◽  
Benoist Laurent ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Molecular Motor ◽  
Opportunistic Pathogen ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
New Class ◽  
Heme Acquisition ◽  
Shed Light

ExbBD is part of a cytoplasmic membrane molecular motor driven by the proton-motive force. It belongs to the larger family of motors involved in nutriment import across the outer membrane of Gram-negative bacteria (ExbBD), flagellar rotation (MotAB) or late steps of cell division in Gram-negative bacteria (TolQR). ExbB and ExbD are integral membrane proteins with three (ExbB) or one (ExbD) transmembrane segment. Here we have solved by single-particle cryo-EM the structures of ExbB alone and of the ExbB-ExbD complex of the opportunistic pathogen Serratia marcescens. ExbBSm alone behaves as a stable pentamer, and the complex displays the ExbB5-ExbD2 stoichiometry. This is similar to what has been observed for ExbB-ExbD complexes from Escherichia coli and Pseudomonas savastanoi as well as MotAB complexes from various species. We identified residues located in the first TM of ExbBSm and ExbBEc that are likely involved in the interaction with TonB/HasB and that are essential for function. ExbBSm has a ca. 40 residues long periplasmic extension absent in E. coli. Such long ExbBs are found in some Gammaproteobacteria, and several genera of Alphaproteobacteria. We show that this extension interacts with HasB, a dedicated TonB paralog from the heme acquisition system (Has) from S. marcescens. We also show that it is involved in heme acquisition via the Has system from S. marcescens. ExbBSm represents thus a new class of ExbB protein and our results shed light on the specificity determinants between the ExbB-ExbD complex and their associated TonB partners.

scholarly journals Model of a critical size defect in the New Zealand White rabbit’s tibia

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Che Nor Zarida Che Seman ◽  
Zamzuri Zakaria ◽  
Mohamed Azril Mohamed Amin ◽  
Mohd Shukrimi Awang ◽  
Nazri Mohd Yusof ◽  
...  
Keyword(s):  
New Zealand ◽  
Critical Size ◽  
Zealand White Rabbit ◽  
Control Group ◽  
Critical Size Defect ◽  
New Zealand White Rabbit ◽  
Surgical Suture ◽  
Study Results ◽  
Rabbit Tibia ◽  
New Zealand White Rabbits

Introduction: Critical size defects (CSD) in the long bones of New Zealand White rabbit (Oryctolagus cuniculus) have been used for years as an experimental model for investigation of the effectiveness of a new bone substitute materials. There are varieties of protocols available in the literature. This technical note attempts to present an alternative surgical technique of a CSD in the New Zealand white rabbit tibia. Methods: Thirty-nine New Zealand White rabbits were used in this study. A CSD of approximately 4.5 mm (width) X 9.0 mm (length) was surgically drilled at the proximal tibial metaphysis, approximately 1 cm from the knee joint. The surrounding of soft tissue was repositioned and sutured layer by layer with bio absorbable surgical suture. Povidone soaked gauze and bandage were used as a dressing. There is no control group used in this study. Results: This alternative method created good CSD with less bleeding from the muscle observed. No mortality on other surgical complications were observed within 6 weeks, 12 weeks and 24 weeks following surgery. Conclusions: A simple and safe method for performing critical size defect was demonstrated and recommended as an approach for surgery on New Zealand White rabbits.

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