Avila-Novoa María Guadalupe, Solis-Velazquez Oscar Alberto, Guerrero-Medina Pedro Javier, Martínez-Chávez Liliana, Martínez-Gonzáles Nanci Edid, Gutiérrez-Lomelí Melesio
Centro de Investigación en Biotecnología Microbiana y Alimentaria, Departamento de Ciencias Básicas, División de Desarrollo Biotecnológico, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Col. Lindavista, Ocotlán 47820, Jalisco, Mexico.
Departamentos de Farmacobiología y Matemáticas, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Blvd. Gral. Marcelino García Barragán 1451, Col. Olímpica, Guadalajara 44430, Jalisco, Mexico.
Antibiotics (Basel). 2024 Nov 3;13(11):1039. doi: 10.3390/antibiotics13111039.
BACKGROUND/OBJECTIVES: is a foodborne pathogen that can infect both humans and animals and cause noninvasive gastrointestinal listeriosis or invasive listeriosis. The objectives of this study were to determine the genetic diversity of ; the genes associated with its resistance to antibiotics, benzalkonium chloride (BC), and cadmium chloride (CdCl); and its biofilm formation.
A total of 132 fresh fruits (44 samples) and vegetables (88 samples) were selected for this study. The genetic diversity of the isolates and the genes associated with their antibiotic resistance were determined using PCR amplification; meanwhile, their levels of susceptibility to antibiotics were determined using the agar diffusion method. Their levels of resistance to BC and CdCl were determined using the minimum inhibitory concentration method, and their capacity for biofilm formation was evaluated using the crystal violet staining method.
A total of 17 strains were collected: 12.8% (17/132) from fresh fruits and vegetables in this study. The isolates of belonged to phylogenetic groups I.1 (29.4% (5/17); serotype 1/2a) and II.2 (70.5% (12/17); serotype 1/2b); strains containing pathogenicity islands (LIPIs) were also identified at prevalence rates of 100% for LIPI-1 and LIPI-2 (17/17), 29.4% for LIPI-3 (5/17), and 11.7% for LIPI-4 (2/17). The antibiotic susceptibility tests showed that the isolates exhibited six different multiresistant patterns, with multiple antibiotic resistance (MAR) index of ≥0.46 (70.5%; 12/17); additionally, the genes and , associated with efflux pump Lde, tetracycline, and ciprofloxacin resistance, were detected at 52.9% (9/17), 29.4% (5/17), and 17.6% (3/17), respectively. The phenotypic tests showed that 58.8% (10/17) of cadmium-resistant isolates had a co-resistance of 23.5% (4/17) to BC. Finally, all strains of exhibited moderate biofilm production.
The results of this study contribute to our understanding of the persistence and genetic diversity of strains isolated from fresh fruits and vegetables; in addition, their resistance to CdCl, which is correlated with co-resistance to BC disinfectant, is helpful for the food industry.
背景/目的：是一种食源性病原体，可感染人类和动物，导致非侵袭性胃肠型李斯特菌病或侵袭性李斯特菌病。本研究的目的是确定的遗传多样性；与其对抗生素、苯扎氯铵（BC）和氯化镉（CdCl）的抗性相关的基因；以及其生物膜形成情况。
本研究共选取了132份新鲜水果（44份样本）和蔬菜（88份样本）。通过PCR扩增确定分离株的遗传多样性及其与抗生素抗性相关的基因；同时，采用琼脂扩散法测定其对抗生素的敏感性水平。采用最低抑菌浓度法测定其对BC和CdCl的抗性水平，采用结晶紫染色法评估其生物膜形成能力。
共收集到17株菌株：本研究中从新鲜水果和蔬菜中分离得到的占12.8%（17/132）。的分离株属于系统发育组I.1（29.4%（5/17）；血清型1/2a）和II.2（70.5%（12/17）；血清型1/2b）；还鉴定出含有致病岛（LIPIs）的菌株，LIPI-1和LIPI-2的流行率为100%（17/17），LIPI-3为29.4%（5/17），LIPI-4为11.7%（2/17）。抗生素敏感性试验表明，分离株表现出六种不同的多重耐药模式，多重耐药（MAR）指数≥0.46（70.5%；12/17）；此外，与外排泵Lde、四环素和环丙沙星抗性相关的基因和分别在52.9%（9/17）、29.4%（5/17）和17.6%（3/17）的菌株中被检测到。表型试验表明，58.8%（10/17）对镉具有抗性的分离株对BC的共抗性为23.5%（4/17）。最后，所有菌株均表现出中等程度的生物膜形成。
本研究结果有助于我们了解从新鲜水果和蔬菜中分离得到的菌株的持久性和遗传多样性；此外，它们对CdCl的抗性与对BC消毒剂的共抗性相关，这对食品工业有帮助。
