Scholarlink

<p><i>Photobacterium damselae</i> poses a significant threat to global aquaculture, causing economic losses due to diseases such as pasteurellosis. With the rise of antibiotic-resistant strains, alternative strategies are essential. This study reports the first isolation and characterization of lytic bacteriophages active against pathogenic <i>P. damselae</i> in India. Five distinct phages (<b>Φ</b>Ph1–<b>Φ</b>Ph5) were isolated from water and fish samples, achieving titers from 1.1 × 10<sup>8</sup> to 1.72 × 10<sup>9</sup> PFU/mL. Transmission Electron Microscopy&#xa0;(TEM) revealed virions with <i>Siphovirus</i>-like morphology, featuring icosahedral heads (60–112&#xa0;nm) and long, non-contractile tails (150–350&#xa0;nm). Host range determination showed high specificity: <b>Φ</b>Ph1–<b>Φ</b>Ph4 exclusively lysed <i>P. damselae</i> isolates (distinguishing activity against PDD and PDP), while Ph5 exhibited a broader range, also infecting <i>Vibrio parahaemolyticus</i>. One-step growth curves revealed latent periods of 50–60&#xa0;min and burst sizes of 70 ± 5 to 118 ± 8 PFU/cell. Physico-chemical studies demonstrated robust stability. <b>Φ</b>Ph1, <b>Φ</b>Ph2, and <b>Φ</b>Ph4 maintained viability up to 60&#xa0;°C. The phages remained stable across pH 5–10, with <b>Φ</b>Ph1 and <b>Φ</b>Ph2 showing tolerance at pH 3. Salinity tolerance generally spanned 0–35 ppt, though <b>Φ</b>Ph1 and <b>Φ</b>Ph5 showed sensitivity at 15–20 ppt. These lytic phages offer a targeted, eco-friendly alternative to antibiotics for managing <i>P. damselae</i> infections. These findings provide a foundation for future in vivo trials and the development of phage-based biocontrol strategies in aquaculture.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Lytic bacteriophages active against Photobacterium damselae: first isolation and characterization from Indian waters

  • 期刊论文

  • 发表日期：

    2026年6月29日

查看全文
  • Mahalakshmi Sivakumar,
  • Chrisolite Bagthasingh,
  • Murugadas Vaiyapuri,
  • Sivasankar Panchavarnam,
  • Manimekalai Durairaj,
  • Subash Palaniappan

摘要

Photobacterium damselae poses a significant threat to global aquaculture, causing economic losses due to diseases such as pasteurellosis. With the rise of antibiotic-resistant strains, alternative strategies are essential. This study reports the first isolation and characterization of lytic bacteriophages active against pathogenic P. damselae in India. Five distinct phages (ΦPh1–ΦPh5) were isolated from water and fish samples, achieving titers from 1.1 × 108 to 1.72 × 109 PFU/mL. Transmission Electron Microscopy (TEM) revealed virions with Siphovirus-like morphology, featuring icosahedral heads (60–112 nm) and long, non-contractile tails (150–350 nm). Host range determination showed high specificity: ΦPh1–ΦPh4 exclusively lysed P. damselae isolates (distinguishing activity against PDD and PDP), while Ph5 exhibited a broader range, also infecting Vibrio parahaemolyticus. One-step growth curves revealed latent periods of 50–60 min and burst sizes of 70 ± 5 to 118 ± 8 PFU/cell. Physico-chemical studies demonstrated robust stability. ΦPh1, ΦPh2, and ΦPh4 maintained viability up to 60 °C. The phages remained stable across pH 5–10, with ΦPh1 and ΦPh2 showing tolerance at pH 3. Salinity tolerance generally spanned 0–35 ppt, though ΦPh1 and ΦPh5 showed sensitivity at 15–20 ppt. These lytic phages offer a targeted, eco-friendly alternative to antibiotics for managing P. damselae infections. These findings provide a foundation for future in vivo trials and the development of phage-based biocontrol strategies in aquaculture.