Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.
Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.
Front Cell Infect Microbiol. 2023 Dec 1;13:1304677. doi: 10.3389/fcimb.2023.1304677. eCollection 2023.
can cause self-limiting gastrointestinal infections, but when infecting the eye, can cause rapid and irreversible blindness. This study investigated whether clinical ocular and gastrointestinal isolates differed in terms of virulence-related genotypes and endophthalmitis virulence.
Twenty-eight ocular, gastrointestinal, and laboratory reference isolates were evaluated. Hemolysis assays were performed to assess potential differences in hemolytic activity. The presence of twenty virulence-related genes was assessed by PCR. A subset of ocular and gastrointestinal isolates differing in PCR positivity for 5 virulence genes was compared to strain ATCC14579 in an experimental murine model of endophthalmitis. At 8 hours post infection, retinal function was evaluated by electroretinography, and intraocular bacterial concentrations were determined by plate counts.
Gastrointestinal isolates were more hemolytic than the ocular isolates and ATCC14579 (p < 0.0001). ocular isolates were more frequently PCR-positive for , and compared to the gastrointestinal isolates (p ≤ 0.0002). In the endophthalmitis model, mean A-wave retention did not differ significantly between eyes infected with ATCC14579 and eyes infected with the selected ocular or gastrointestinal isolates (p ≥ 0.3528). Similar results were observed for mean B-wave retention (p ≥ 0.0640). Only one diarrheal isolate showed significantly greater B-wave retention when compared to ATCC14579 (p = 0.0303). No significant differences in mean A-wave (p ≥ 0.1535) or B-wave (p ≥ 0.0727) retention between the selected ocular and gastrointestinal isolates were observed. Intraocular concentrations of ATCC14579 were significantly higher than the selected ocular isolate and 3 of the gastrointestinal isolates (p ≤ 0.0303). Intraocular concentrations of the selected ocular isolate were not significantly different from the gastrointestinal isolates (p ≥ 0.1923).
Among the subset of virulence-related genes assessed, 5 were significantly enriched among the ocular isolates compared to gastrointestinal isolates. While hemolytic activity was higher among gastrointestinal isolates, retinal function retention and intraocular growth was not significantly different between the selected ocular and gastrointestinal isolates. These results suggest that strains causing gastrointestinal infections, while differing from ocular isolates in hemolytic activity and virulence-related gene profile, are similarly virulent in endophthalmitis.
可引起自限性胃肠道感染，但感染眼部时，可导致快速且不可逆转的失明。本研究旨在探讨临床眼部和胃肠道分离株在与毒力相关的基因型和眼内炎毒力方面是否存在差异。
评估了 28 例眼部、胃肠道和实验室参考分离株。通过溶血试验评估潜在的溶血活性差异。通过 PCR 评估 20 种毒力相关基因的存在情况。眼部和胃肠道分离株中 PCR 阳性的 5 种毒力基因子集与 ATCC14579 在实验性眼内炎小鼠模型中进行比较。感染后 8 小时，通过视网膜电图评估视网膜功能，通过平板计数法确定眼内细菌浓度。
胃肠道分离株的溶血活性明显高于眼部分离株和 ATCC14579（p<0.0001）。眼部分离株与胃肠道分离株相比，更为频繁地 PCR 阳性，（p≤0.0002）。在眼内炎模型中，感染 ATCC14579 的眼与感染所选眼部或胃肠道分离株的眼之间的平均 A 波保留率无显著差异（p≥0.3528）。平均 B 波保留率也观察到类似结果（p≥0.0640）。与 ATCC14579 相比，仅 1 株腹泻分离株的 B 波保留率显著升高（p=0.0303）。所选眼部和胃肠道分离株之间的平均 A 波（p≥0.1535）或 B 波（p≥0.0727）保留率无显著差异。ATCC14579 的眼内浓度明显高于所选眼部分离株和 3 株胃肠道分离株（p≤0.0303）。所选眼部分离株的眼内浓度与胃肠道分离株无显著差异（p≥0.1923）。
在所评估的毒力相关基因亚集中，5 种基因在眼部分离株中明显比胃肠道分离株富集。虽然胃肠道分离株的溶血活性较高，但所选眼部和胃肠道分离株之间的视网膜功能保留和眼内生长并无显著差异。这些结果表明，引起胃肠道感染的菌株，尽管在溶血活性和与毒力相关的基因谱方面与眼部分离株不同，但在眼内炎中具有相似的毒力。
