Male balb c mice

Twenty CBA/J female mice and five BALB/c male mice and five DBA/2 male mice (6-week-old) were purchased from Beijing Vital River Laboratory Animal Technology Co. Ltd., China. They were in adaptive culture for 5 days in specific pathogen-free (SPF) in Renmin Hospital of Wuhan University. Ten CBA/J female mice and five BALB/c male micee were mated to construct the control model, ten CBA/J female micee and five BALB/c male micee were mated to construct the normal pregnancy control model, and ten CBA/J female mice and five DBA/2 male mice were mated to construct the spontaneous abortion model (Clark, 2020 (link)). Detection of a vaginal plug was chosen to indicate day 0.5 of gestation. All mice were killed at day 12.5 to examine and calculate the embryo resorption rate. All animal studies were approved by the ethics committee for laboratory animal welfare (IACUC) of Renmin Hospital of Wuhan University [No. WDRM animal (f) No. 20201207].

Thirty-six six-week-old BALB/c male mice were obtained from Beijing Vital River Laboratory Animal Technology Co., Ltd. (Beijing, China). They were housed under controlled conditions with a temperature of 25 ± 2 °C, a humidity of 50 ± 5%, and a 12 h light/dark cycle. The animal experiment received ethical approval from the Animal Ethics Committee of Northeast Agricultural University, with the ethical approval code NEAUEC20220363. All the mice were acclimatized for 7 days before the experiment and randomly divided into 4 groups. The experimental groups of mice are described in Table 1. From day 1 to day 7, 0.2 mL of PBS was given to the control and model groups, and 0.2 mL of B. longum K5 was given to the K5-EHEC and K5-PBS groups. From day 8 to day 14, 0.2 mL of PBS was given to the control and K5-PBS groups, and 0.2 mL of EHEC O157:H7 was given to the model and K5-EHEC groups. It was worth mentioning that the concentration of EHEC O157:H7 was adjusted to 1.0 × 10⁸ CFU/mL, while B. longum K5 was adjusted to a concentration of 1.0 × 10⁹ CFU/mL for gavage.

BALB/c male mice were purchased from Beijing Vital River Laboratory Animal Technology Co. Ltd. (Beijing, China), and maintained under specific pathogen-free conditions. All procedures were approved and conducted under the Guideline for the Institutional Animal Care and Use Committee of Soochow University.

A total of 36 six-week-old BALB/c male mice were purchased from Beijing Vital River Laboratory Animal Technology Co. Ltd. (Beijing, China). They were housed in individually ventilated cages with ad libitum access to water and food under specific pathogen-free conditions. The ambient temperature (23 ± 1 °C), humidity (50–70%), and light conditions (12/12-h light/dark cycle) were strictly controlled. After adaptive feeding for 7 days, mice were used for the isolation of primary splenic cells or the administration of bacterial strains. The Experimental Animal Management Committee of Sichuan Government approved the animal experimental facility and experimental protocols used in this study (approval number: SYXK2018-011).

Six-week-old specific-pathogen-free BALB/c male mice (n = 48) with body weight (20 ± 2) g were purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd. [license number: SYXK (Beijing) 2016-0006]. They were housed in IVCs in the animal laboratory of the Beijing University of Chinese Medicine, at an ambient temperature of (25 ± 2)°C and humidity of 40%–60%, and they had free access to food and water daily.
After 7 days of adaptive feeding, the mice were randomly divided into two groups: n (AD) = 24 and n (CONT) = 24. A total of six mice from each group were sacrificed on days 11, 25, 39, and 46 during the experiment.

Sixteen Balb/c male mice (5 weeks old, weighing 26 ± 2 g) were purchased from the Vital River Laboratory Animal Technology Ltd., Beijing, China [Animal Certificate Number: SCXK(jing)2021–0006]. All animal studies were approved by the Animal Ethics Committee of Inner Mongolia Medical University (Ethics Approval Number: YKD2019143) and carried out in accordance with the relevant guidelines and regulations for the use and care of animals. This study was performed in compliance with the ARRIVE guidelines. All mice were housed in a room under standardized conditions at 21–25 °C, 45–65% humidity, and a 12-h light–dark cycle. The mice were randomly divided into four groups of 4 animals each: (I) intraperitoneal (i.p.) saline group (0.9% NaCl), (II) i.p. 6 h after LPS (3.3 mg/kg) injection group (6 h LPS), (III) i.p. 12 h after LPS (3.3 mg/kg) injection group (12 h LPS) and (IV) i.p. 24 h after LPS (3.3 mg/kg) injection group (24 h LPS). LPS-induced acute orchitis protocol was performed according to the procedure originally described by Haley and McCormick^{20 (link)}. All mice were anesthetized with sodium pentobarbitol (60 mg/kg) and sacrificed. Then the testes were removed for further study. One of a pair of testes from each group was fixed in 10% formalin for histological analysis, the other one was stored at -80 °C for RNA isolation. The epididymis was collected for sperm analysis.