Given the need to understand the virulence profile of Proteus mirabilis isolates from cellulitis in broiler chickens and their ability to cause lesions, the present study aimed to characterize genotypically and phenotypically the virulence profiles of two strains of P. mirabilis isolated from cellulitis in broilers, as well as to evaluate their ability to experimentally reproduce the lesions in vivo. The strain with the highest virulence potential (LBUEL-A33) possessed mrpA , pmfA , ucaA , atfA (fimbriae), zapA , ptA (proteases), hpmA (hemolysin), and ireA (siderophore) genes, formed a very strong biofilm, and expressed the pattern of aggregative adhesion and cytotoxicity in Vero cells. The strain with the lowest virulence potential (LBUEL-A34) did not present the pmfA and ucaA genes, but expressed the pattern of aggregative adhesion, formed a strong biofilm, and did not show cytotoxicity. Both strains developed cellulitis in an animal model within 24 h post-inoculation (PI), and the degree of lesions was not significantly altered up to 120 h PI. The LBUEL-A33 strain was also inoculated in combination with an avian pathogenic Escherichia coli (APEC 046), and the lesions showed no significant changes from the individual inoculation of these two strains. Histological analysis showed that the LBUEL-A33 strain developed characteristic cellulitis lesions. Thus, both strains of P. mirabilis isolated in our study have several virulence factors and the ability to develop cellulitis in broilers.

中文翻译：

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奇异变形杆菌引起肉鸡蜂窝织炎

鉴于需要了解从肉鸡蜂窝织炎中分离出的奇异变形杆菌的毒力谱及其引起病变的能力，本研究旨在从基因型和表型上表征从肉鸡蜂窝织炎中分离出的奇异变形杆菌的两种菌株的毒力谱，如以及评估他们在体内实验复制病变的能力。毒力最高的菌株（LBUEL-A33）具有mrpA、pmfA、ucaA、atfA（菌毛）、zapA、ptA（蛋白酶）、hpmA（溶血素）和ireA（铁载体）基因，形成了非常强的生物膜，并且表达了 Vero 细胞中聚集粘附和细胞毒性的模式。具有最低毒力潜力的菌株（LBUEL-A34）不存在 pmfA 和 ucaA 基因，但表达了聚集粘附模式，形成了强大的生物膜，并且没有表现出细胞毒性。两种菌株在接种后 (PI) 24 小时内在动物模型中都发生了蜂窝织炎，并且在接种后 120 小时内病变程度没有显着改变。LBUEL-A33菌株还与禽致病性大肠杆菌（APEC 046）联合接种，与这两种菌株的单独接种相比，病变没有显着变化。组织学分析显示 LBUEL-A33 菌株发展出特征性蜂窝织炎病变。因此，在我们的研究中分离出的两种奇异假单胞菌菌株都具有多种毒力因子和在肉鸡中发生蜂窝织炎的能力。直到 120 小时 PI，病变程度没有显着改变。LBUEL-A33菌株还与禽致病性大肠杆菌（APEC 046）联合接种，与这两种菌株的单独接种相比，病变没有显着变化。组织学分析显示 LBUEL-A33 菌株发展出特征性蜂窝织炎病变。因此，在我们的研究中分离出的两种奇异假单胞菌菌株都具有多种毒力因子和在肉鸡中发生蜂窝织炎的能力。直到 120 小时 PI，病变程度没有显着改变。LBUEL-A33菌株还与禽致病性大肠杆菌（APEC 046）联合接种，与这两种菌株的单独接种相比，病变没有显着变化。组织学分析显示 LBUEL-A33 菌株发展出特征性蜂窝织炎病变。因此，在我们的研究中分离出的两种奇异假单胞菌菌株都具有多种毒力因子和在肉鸡中发生蜂窝织炎的能力。