文献类型： 外文期刊

作者： Mohiuddin, Mudassar ¹ ; Song, Zhongfeng ¹ ; Liao, Shenquan ¹ ; Qi, Nanshan ¹ ; Li, Juan ¹ ; Lv, Minna ¹ ; Lin, Xuhui ¹ ; Cai, Haiming ¹ ; Hu, Junjing ¹ ; Liu, Shaobing ¹ ; Zhang, Jianfei ¹ ; Gu, Youfang ³ ; Sun, Mingfei ¹ ;

作者机构： 1.Guangdong Acad Agr Sci, Key Lab Livestock Dis Prevent Guangdong Prov, Key Lab Avian Influenza & Other Major Poultry Dis, Inst Anim Hlth,Minist Agr & Rural Affairs, Guangzhou 510640, Peoples R China

2.Islamia Univ Bahawalpur, Fac Vet & Anim Sci, Dept Microbiol, Bahawalpur 63100, Pakistan

3.Anhui Sci & Technol Univ, Coll Anim Sci & Technol, Chuzhou 233100, Peoples R China

关键词： necrotic enteritis; C; perfringens; netB gene; animal model studies; amoxicillin

期刊名称：MICROORGANISMS （ 影响因子：4.5； 五年影响因子：4.8 ）

ISSN：

年卷期： 2023 年 11 卷 3 期

页码：

收录情况： SCI

摘要： Poultry necrotic enteritis (NE) is a complex and multifactorial disease caused by Clostridium perfringens types. Earlier, the disease was prevented and/or controlled through the addition of in-feed antibiotics and antimicrobial growth promoters (AGPs). The ban on the use of these agents as feed additives has been a major reason for re-emergence of this disease leading to huge economic losses to the world poultry industry. Understanding the pathogenesis of NE by developing an effective experimental model remains challenging and lacks consistency owing to the involvement of several critical factors involved in causing lesions of disease in the field. In this study, locally characterized C. perfringens types, i.e., ACP (toxinotype A), and GCP (toxinotype G), obtained from NE outbreaks on commercial farms in China (2020-2022), were used to experimentally induce NE in Specific-Pathogen-Free (SPF) chicks. The lesion scores observed on day 20 were 1.9 +/- 1.10 (GCP strain) and 1.5 +/- 1.08 (ACP strain), and both had significant difference as compared to the control group. The inclusion of fishmeal in addition to oral clostridial dose, i.e., fishmeal (day 7 onward) + Clostridia (7.5 x 10(8) cfu/mL consecutively for 04 days) induced a lesion score of 2.0 +/- 1.15 in respective groups. Use of coccidia (Eimeria necatrix) on day 9 followed by clostridia challenge enhanced the lesion scores to 2.5 +/- 1.08 and 2.2 +/- 1.23 for type G and type A strains, respectively. When both predisposing factors (coccidia + fish meal) were given together, i.e., fishmeal (day 7 onward) and coccidia (day 9) along with clostridia, the lesion scores were 3.2 +/- 1.22 (GCP + coccidia + fish meal) and 3.0 +/- 1.15 (ACP + coccidia + fish meal). These results were significantly different from group 1 (ACP) and 2 (GCP), in which only C. perfringens was used to induce NE. The clinical signs as well as histopathological lesions in experimentally induced groups were found similar as reported in the literature. The two type G strains identified in this study were also used for susceptibility testing against various drugs. Both strains were found to be resistant to amikacin, doxycycline, metronidazole, neomycin, nystatin, polymyxin B, streptomycin, and tetracycline. Variable susceptibility was seen against ceftriaxone, florfenicol, gentamicin, and kanamycin drugs. Amoxicillin, ampicillin, cefotaxime, ciprofloxacin, enrofloxacin, ofloxacin, and penicillin were effective drugs based upon their low level of resistance and therefore they might be preferred over other antimicrobial agents for proper treatment/prophylaxis of NE infections. Further studies are needed to study the pathogenesis of NE in detail in experimentally induced models along with continuous monitoring of the resistance pattern of C. perfringens strains in the field.