Bacterial enteritis in ostrich (Struthio Camelus) chicks in the Western Cape Province, South Africa

First Report of Respiratory Infection Caused by Multidrug-Resistant Escherichia coli in an Ostrich in Romania

INTRODUCTION

Ostrich farming is increasingly recognized for its economic potential but poses significant health challenges due to the risk of pathogen transmission, including multidrug-resistant Escherichia coli.

CASE STUDY

This study reports a case of a four-month-old female ostrich from western Romania presenting with severe respiratory and digestive infections, progressing to septicemia and death. A post-mortem examination revealed extensive mucus in the trachea, pulmonary congestion, hemorrhagic enteritis, and approximately 1250 g of metal objects in the ventriculus. Pure cultures of E. coli were isolated from the lungs and bone marrow and identified via MALDI-TOF MS. The strain exhibited multidrug resistance to several antibiotics, including enrofloxacin, doxycycline, and amoxicillin, highlighting the critical issue of antimicrobial resistance in veterinary medicine.

DISCUSSIONS

This case underscores the need for enhanced management practices in ostrich farming to mitigate environmental and pathogenic risks, as well as the urgency of developing alternative strategies for controlling resistant bacterial infections in avian species.

CONCLUSIONS

This case highlights the need for alternative treatments and stricter antimicrobial stewardship to combat multidrug-resistant E. coli in ostriches.

Chicory supplementation improves growth performance in juvenile ostriches potentially by attenuating enteritis

Introduction

Enteritis and dysbiosis are the major causes of high morbidity and mortality of juvenile ostriches. Chicory (CC) has been proven to have excellent antioxidant, anti-inflammatory, and antibacterial activities. However, it's unclear whether CC could improve the survival rate of juvenile ostriches by relieving enteritis and correcting dysbiosis.

Materials and methods

South African ostrich hatchlings (Struthio camelus domesticus) were fed with and without a CC-supplemented diet, and the body weight gain and mortality were compared over 4 months of age. Fresh fecal samples of clinically healthy ostriches were collected, and 16S DNAs were analyzed. Moreover, ostrich chicks with LPS-induced enteritis were fed with different dosages (0, 20, 40, and 80 mg/kg) of chicoric acid (CA), a major bioactive component of CC, for five consecutive days. The expression levels of tight junction (TJ)-related proteins and inflammatory mediators in the ilea were detected with western blot and immunofluorescence.

Results

The ostrich chicks fed on the CC-supplemented diet began to increase in weight at the 1st month of age and became remarkably heavier at the fourth month (p < 0.01) compared with those fed on the non-CC-supplemented diet. Additionally, the mortality percentage was lower in the chicks fed on the CC-supplemented diet than those fed on the non-CC-supplemented diet (19% vs. 36%, respectively). The diet with the CC supplementation significantly increased the abundance of Phascolactobacteria (linear discriminant analysis; LDA >4) and Bacteroidota (26.7% vs. 17.7%, respectively) as well as decreased the enrichment of Clostridium (5.0% vs. 9.1%, respectively) in the ostrich ilea compared to the diet without CC. The supplementation of CA at a dose of 80 mg/kg significantly increased the expression level of ZO-1 and claudin-3 (p < 0.0001) and suppressed the levels of IL-1β, IL-6, and TNF-α (p < 0.0001) in ostriches with LPS-induced ileitis.

Conclusion

Our results substantiate that CC or CA supplementation in a diet could effectively improve growth performance and reduce mortality in juvenile ostriches via modulating the gut microbiota and attenuating enteritis.

Coprophagy rapidly matures juvenile gut microbiota in a precocial bird

Coprophagy is a behavior where animals consume feces, and has been observed across a wide range of species, including birds and mammals. The phenomenon is particularly prevalent in juveniles, but the reasons for this remain unclear. One hypothesis is that coprophagy enables offspring to acquire beneficial gut microbes that aid development. However, despite the potential importance of this behavior, studies investigating the effects in juveniles are rare. Here we experimentally test this idea by examining how ingestion of adult feces by ostrich chicks affects their gut microbiota development, growth, feeding behavior, pathogen abundance, and mortality. We conducted extensive longitudinal experiments for 8 weeks, repeated over 2 years. It involved 240 chicks, of which 128 were provided daily access to fresh fecal material from adults and 112 were simultaneously given a control treatment. Repeated measures, behavioral observations, and DNA metabarcoding of the microbial gut community, both prior to and over the course of the experiment, allowed us to evaluate multiple aspects of the behavior. The results show that coprophagy causes (a) marked shifts to the juvenile gut microbiota, including a major increase in diversity and rapid maturation of the microbial composition, (b) higher growth rates (fecal-supplemented chicks became 9.4% heavier at 8 weeks old), (c) changes to overall feeding behavior but no differences in feed intake, (d) lower abundance of a common gut pathogen (Clostridium colinum), and (e) lower mortality associated with gut disease. Together, our results suggest that the behavior of coprophagy in juveniles is highly beneficial and may have evolved to accelerate the development of gut microbiota.

A calf with hind limb paralysis and dysstasia and a genome sequence analysis of an isolated Clostridium perfringens toxinotype E strain

Clostridium perfringens toxinotype E infections are rare in calves, and the development of intestinal lesions were commonly observed. In 2012, a 6-day-old calf in Japan exhibited swelling with emphysema on the right gluteal region, sudden paralysis of the hind limb and dysstasia. A pathological examination revealed myositis of the gluteal muscle and neuritis of the ischiatic nerve. C. perfringens type E strain CP118 was isolated from the affected muscle. However, the intestinal symptoms and lesions that commonly develop in type E infections in calves were not detected in the present case. Genome analyses revealed that CP118 possessed 16 virulence-related genes, including enterotoxin, and was closely related to other type E and F strains. Particularly, CP118 was more closely related to type E strains from humans, including a food poisoning case, than calf isolates, suggesting its potential to cause food poisoning in humans and, thus, its importance as a potential risk to public health. Since CP118 did not possess the reported toxin genes associated with neuropathy, pyogenic inflammation caused by CP118 and/or other bacteria may have damaged the ischiatic nerve, resulting in neuropathy. Alternatively, unidentified CP118 toxins may have caused the neuropathy. This is the first study to report C. perfringens type E infection with peripheral neuropathy. The distribution of all the reported virulence-related genes in the C. perfringens population as well as the details of this rare case will provide further insights into C. perfringens type E infections.

A Public Health Insight into Salmonella in Poultry in Africa: A Review of the Past Decade: 2010-2020

Poultry is a cheap source of animal protein and constituent of diets in Africa. Poultry can serve as a reservoir for Salmonella and cause food-borne infections in humans. This review describes Salmonella contamination of food, poultry, and the farming environment, antimicrobial resistance profiles, and serotypes of Salmonella, as well as the farming systems, antimicrobial use (AMU), hygiene, and husbandry conditions used to rear poultry in Africa. Using the PRISMA (preferred reporting items for systematic reviews and meta-analysis) guidelines, PubMed, Science Direct, and Web of Science databases were searched using a set of predefined keywords. Full-length research articles in English were examined for the period 2010-2020 and relevant information extracted for the narrative synthesis. Of the articles that met the inclusion criteria, 63.1% were conducted on farms and among households, while 36.9% were undertaken at government-controlled laboratories, which quarantine imported birds, processing plants, and retail outlets. The farming systems were intensive, semi-intensive, and extensive. AMU was described in 11.5% of the studies and varied within and across countries. Multidrug-resistant (MDR) Salmonella isolates were detected in 30 studies and the prevalence ranged from 12.1% in Zimbabwe to 100% in Egypt, Ethiopia, Nigeria, Senegal, and South Africa. A total of 226 different Salmonella serotypes were reported. Twenty-four (19.7%) of the studies reported food-borne Salmonella contamination in eggs, poultry, and poultry products at retail outlets and processing plants. The apparent extensive use of antimicrobials and circulation of MDR Salmonella isolates of various serotypes in Africa is a concern. It is important to implement stricter biosecurity measures on farms, regulate the use of antimicrobials and implement surveillance systems, in addition to food safety measures to monitor the quality of poultry and poultry products for human consumption.

Early-life gut dysbiosis linked to juvenile mortality in ostriches

BACKGROUND

Imbalances in the gut microbial community (dysbiosis) of vertebrates have been associated with several gastrointestinal and autoimmune diseases. However, it is unclear which taxa are associated with gut dysbiosis, and if particular gut regions or specific time periods during ontogeny are more susceptible. We also know very little of this process in non-model organisms, despite an increasing realization of the general importance of gut microbiota for health.

METHODS

Here, we examine the changes that occur in the microbiome during dysbiosis in different parts of the gastrointestinal tract in a long-lived bird with high juvenile mortality, the ostrich (Struthio camelus). We evaluated the 16S rRNA gene composition of the ileum, cecum, and colon of 68 individuals that died of suspected enterocolitis during the first 3 months of life (diseased individuals), and of 50 healthy individuals that were euthanized as age-matched controls. We combined these data with longitudinal environmental and fecal sampling to identify potential sources of pathogenic bacteria and to unravel at which stage of development dysbiosis-associated bacteria emerge.

RESULTS

Diseased individuals had drastically lower microbial alpha diversity and differed substantially in their microbial beta diversity from control individuals in all three regions of the gastrointestinal tract. The clear relationship between low diversity and disease was consistent across all ages in the ileum, but decreased with age in the cecum and colon. Several taxa were associated with mortality (Enterobacteriaceae, Peptostreptococcaceae, Porphyromonadaceae, Clostridium), while others were associated with health (Lachnospiraceae, Ruminococcaceae, Erysipelotrichaceae, Turicibacter, Roseburia). Environmental samples showed no evidence of dysbiosis-associated bacteria being present in either the food, water, or soil substrate. Instead, the repeated fecal sampling showed that pathobionts were already present shortly after hatching and proliferated in individuals with low microbial diversity, resulting in high mortality several weeks later.

CONCLUSIONS

Identifying the origins of pathobionts in neonates and the factors that subsequently influence the establishment of diverse gut microbiota may be key to understanding dysbiosis and host development. Video Abstract.

Insights on toxin genotyping, virulence, antibiogram profiling, biofilm formation and efficacy of disinfectants on biofilms of Clostridium perfringens isolated from poultry, animals and humans

AIMS

This study aimed to determine the toxin genotypes, virulence determinants and antibiogram of Clostridium perfringens isolated from poultry, animals and humans. Biofilm formation and the efficacy of disinfectants on C. perfringens biofilms were studied.

METHODS AND RESULTS

Thirty C. perfringens isolates (20 clinical and 10 from chicken carcasses) were genotyped by PCR and all isolates were genotype A (cpa+). The overall prevalence of cpe, cpb2, netB and tpeL virulence genes was 6·7, 56·7, 56·7 and 36·7% respectively. Twenty-one isolates (70%) were multidrug-resistant, 8 (26·7%) were extensive drug-resistant and one isolate (3·3%) was pan drug-resistant. The average multiple antibiotic resistance index was 0·7. Biofilms were produced by 63·3% of C. perfringens isolates and categorized as weak (36·7%), moderate (16·7%) and strong (10%). Sodium hypochlorite caused significant reduction in C. perfringens biofilms (P < 0·0001).

CONCLUSIONS

All C. perfringens strains in this study were type A, resistant to multiple antibiotics and most of them were biofilm producers. Sodium hypochlorite showed higher efficacy in reducing C. perfringens biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study reported the efficacy of disinfectants in reducing C. perfringens biofilms of economic and public health concern and recommends application on surfaces in farms, food processing plants and slaughterhouses.

Isolation and characterization of Clostridium perfringens strains isolated from ostriches (Struthio camelus) in Vietnam

Background and Aim:

Clostridium perfringens can cause enteritis in ostriches. The toxin release is believed to play a major role in determining pathogenesis properties of these pathogenic bacteria. This study was conducted to isolate and characterize C. perfringens strains from ostriches in Vietnam for identifying if particular virulence factors of these pathogenic bacteria are associated with enteritis progress in ostriches.

Materials and Methods:

The prevalence of cpa, cpb, iA, etx, cpe, and cpb2 genes among C. perfringens isolates was determined by a multiplex polymerase chain reaction (PCR) method. The NetB toxin-encoding gene was detected by PCR and then sequenced to observe their variation. The expression of NetB toxin was checked by SDS-PAGE.

Results:

A total of 116 C. perfringens isolates were obtained from 318 fecal samples and 105 intestinal organs. Of 80 isolates from fecal samples, 33 isolates were from healthy and 47 isolates were from diseased ostriches. The results of multiplex PCR showed that all 116 C. perfringens strains from healthy and enteric disordered ostriches were positive for the alpha toxin-encoding gene (cpa). The cpe and cpb2 genes were found in only one and five diseased ostriches, respectively. The netB gene was detected in 1/33 (3.03%) C. perfringens isolates from healthy ostriches, in 8/47 (17.05%) isolates from feces, and in 7/36 (19.44%) intestinal contents of diseased ostriches. The full-length sequences of 5 out of 15 netB-positive isolates from diseased ostriches showed 100% identity to each other as well as to the netB sequences available in GenBank. All of these five isolates produced NetB toxin in vitro.

Conclusion:

Type A is the most prevalent among C. perfringens isolates from ostriches in Vietnam. Especially, the study provides data emphasizing the role of NetB toxin in causing necrotic enteritis by C. perfringens in ostriches.

Extensive human presence and regular gentle handling improve growth, survival and immune competence in ostrich chicks

A total of 416 day-old ostrich chicks were randomly allocated to one of the three different husbandry practices for 3 months after hatch; HP1 (extensive human presence with gentle human voice, visual and gentle physical stimuli), HP2 (similar to HP1 but without physical stimuli) and S (human presence limited to supply of feed and water). Chick weight (kg) was measured at 6 and 12 weeks of age, while mortalities were recorded daily to calculate the survival rate. Finally, chicks' antibody responses to vaccination against Newcastle disease (NCD) was measured using the Hemagglutination-Inhibition (HI) test at 20 weeks of age. While HP1 chicks were heavier and survived better to 6 weeks of age than HP2 and S chicks (p < .05), no difference was observed thereafter (p > .05). Furthermore, HP1 chicks had an improved immune competence, as illustrated by their lower percentage of positive HI titers, compared to HP2 and S chicks (p < .05). Hence, integrating extensive human presence with positive human-chick interactions may assist in alleviating challenges related to chick rearing in the ostrich industry.

Two Clostridiumperfringens Type E Isolates in France

Clostridiumperfringens type E is a less frequently isolated C.perfringens type and has not previously been reported in France. We have characterized two recent type E isolates, C.perfringens 508.17 from the intestinal content of a calf that died of enterotoxemia, and 515.17 from the stool of a 60-year-old woman, subsequent to food poisoning, which contained the plasmid pCPPB-1 with variant iota toxin and C. perfringens enterotoxin genes.