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

## TL;DR

This study reports the first case of Pseudomonas aeruginosa isolated from a diarrheal cynomolgus monkey, including its identification and drug sensitivity profile.

## Contribution

The first reported isolation of P. aeruginosa from the diarrhea feces of a cynomolgus monkey, with detailed drug sensitivity results.

## Key findings

- The isolated strain PA/CM-101101 showed strong pathogenicity in mice and formed distinct colony morphologies on different media.
- The strain was sensitive to 13 antibiotics but resistant to ampicillin, cefadroxil, cefazolin, erythromycin, and vancomycin.
- 16S rRNA gene sequencing confirmed over 98.4% similarity with known P. aeruginosa strains in GenBank.

## Abstract

Pseudomonas aeruginosa (P. aeruginosa) is an aerobic, non-fermentative, oxidase-positive, small Gram-negative bacterium typically found in single pairs. It is a prevalent opportunistic pathogen in clinical practice that can cause healthcare-associated infections in both humans and animals, including goat, dog, cat, cow, forest musk deer, mink, blue fox, and so on. P. aeruginosa plays a significant role in diseases such as intestinal infections. We confirmed that P. aeruginosa was identified as the pathogen in the diarrhea feces of a cynomolgus monkey through morphological analysis, biochemical tests, 16S rRNA gene sequencing, and animal pathogenicity experiments. Additionally, we performed drug sensitivity testing on P. aeruginosa. So far, this is the first case of P. aeruginosa isolated from the diarrhea feces of a cynomolgus monkey. This study provides an important scientific foundation for isolating and identifying P. aeruginosa as well as for preventing and treating bacterial diseases in experimental monkeys.

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.