Isolation, Identification, and Drug Sensitivity Test of Pseudomonas aeruginosa from Cynomolgus Monkey (Macaca fascicularis)

Abstract

In this study, we isolated and identified bacteria from the feces of a diarrheal cynomolgus monkey. The results showed that the isolated strain was P. aeruginosa, named PA/CM-101101. Morphological observations indicated that when cultured on Luria-Bertani (LB) nutrient agar at 37 °C for 24 h, the strain formed smooth, slightly elevated colonies with neat and wavy edges. On acetamide agar at the same temperature and duration, the colonies appeared flat with irregular edges and a faint pink periphery, while the medium changed to rose-red; in LB broth at 37 °C for 24 h, the medium became turbid and yellowish-green. Gram staining revealed that it was negative and rod-shaped, without sporulation characteristics. The 16S rRNA gene sequence analysis showed that the sequence identity of the strain shared more than 98.4% similarity with 11 strains of P. aeruginosa from various sources in GenBank. The animal toxicity test showed that it had a strong pathogenic effect on mice. The results of drug sensitivity tests showed that strain PA/CM-101101 was sensitive to amikacin, azithromycin, cefoperazone, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, levofloxacin, meropenem, norfloxacin, ofloxacin, and polymyxin B; however, it displayed resistance to ampicillin, cefadroxil, cefazolin, erythromycin, and vancomycin. The research findings provide valuable insights for diagnosis and treatment strategies for cynomolgus monkeys. It also provides a reference for molecular epidemiological studies. To our knowledge, this is the first time P. aeruginosa isolated from the diarrhea feces of cynomolgus monkey has been reported.

Keywords: Pseudomonas aeruginosa; cynomolgus monkey; drug sensitivity test; identification.

Figure 1

The morphology of P. aeruginosa isolated from a cynomolgus monkey. (A) Morphological observations of the P. aeruginosa isolate on an LB agar plate. (B) Morphological characteristics of the isolate on acetamide agar. (C) Morphological observations of the P. aeruginosa isolate in LB broth. (D) Morphological observations of the P. aeruginosa and Gram staining microscopy results.

Figure 2

Identification of PCR-amplified P. aeruginosa with 16S rRNA gene in a cynomolgus monkey (M: DL-2K marker; 1: sample; 2: negative control).

Figure 3

Comparison of similarity between P. aeruginosa of a cynomolgus monkey (Macaca fascicularis) (PA/CM-101101) and other strains. “▲” is the isolated strain in this study.

Figure 4

Phylogenetic tree of 16S rRNA sequences among different reported strains of P. aeruginosa, including cynomolgus monkey (Macaca fascicularis) (PA/CM-101101). “▲” is the isolated strain in this study.