Faculty of Biotechnology, Atma Jaya Catholic University of Indonesia, Jalan Jenderal Sudirman, Jakarta, 12930, Indonesia.
Present Address: Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, 115.
BMC Microbiol. 2022 Apr 27;22(1):116. doi: 10.1186/s12866-022-02521-1.
Ice nucleation active (INA) bacteria are a group of microorganisms that can act as biological nucleator due to their ice nucleation protein property. Unfortunately, little is known about their prevalence and characteristics in tropical areas including Indonesia. Here, we monitor the presence of INA bacteria in rainwater and air samples collected from Jakarta, Tangerang and several areas in Western Java, Indonesia for one year. We further identify and characterize selected Class A of INA bacteria isolated from these areas.
Most of the INA bacteria were isolated from rainwater samples collected during March-August 2010, particularly from Jakarta, Bandung, and Tangerang. A total of 1,902 bacterial isolates were recovered from these area. We found a limited number of bacterial isolates from air sampling. From ice nucleation activity assays, 101 INA isolates were found active as ice nucleator at a temperature above -10 °C. A large majority (73 isolates) of them are classified as Class C (active below -8 °C), followed by Class A (26 isolates; active at -2 to -5 °C) and Class B (two isolates; active at -5 to -8 °C). We sequenced the 16S rRNA gene of 18 Class A INA isolates and identified 15 isolates as Enterobacteriaceae, while the remaining three as Pseudomonadaceae. The vast majority of our Class A INA isolates were likely Pantoea spp. with several isolates were deduced as either Pseudomonas, Cronobacter, and Klebsiella. We found that these 18 Class A INA isolates had acquired resistance to antibiotics erythromycin and ampicillin, which are considered two critically important antibiotics.
Our results showed that the prevalence of INA bacterial population varies across locations and seasons. Furthermore, our isolates were dominated by Class A and C INA bacteria. This study also cautions regarding the spread of antibiotic resistance among INA bacteria.
冰核活性（INA）细菌是一群能够因其冰核蛋白特性而充当生物成核剂的微生物。遗憾的是，人们对包括印度尼西亚在内的热带地区 INA 细菌的流行情况和特征知之甚少。在这里，我们监测了一年来从印度尼西亚雅加达、丹格朗和西爪哇省几个地区采集的雨水和空气样本中 INA 细菌的存在情况。我们进一步鉴定和表征了从这些地区分离出的选定 A 类 INA 细菌。
大多数 INA 细菌是从 2010 年 3 月至 8 月采集的雨水样本中分离出来的，特别是从雅加达、万隆和丹格朗采集的样本。从这些地区共回收了 1902 株细菌分离株。我们从空气采样中发现了数量有限的细菌分离株。通过冰核活性测定，发现 101 株 INA 分离株在-10°C 以上的温度下具有冰核活性。其中绝大多数（73 株）为 C 类（-8°C 以下活性），其次是 A 类（26 株；-2 至-5°C 活性）和 B 类（2 株；-5 至-8°C 活性）。我们对 18 株 A 类 INA 分离株的 16S rRNA 基因进行了测序，鉴定出 15 株为肠杆菌科，其余 3 株为假单胞菌科。我们的 A 类 INA 分离株绝大多数可能为 Pantoea spp.，其中几株推断为 Pseudomonas、Cronobacter 和 Klebsiella。我们发现这些 18 株 A 类 INA 分离株对红霉素和氨苄西林这两种重要抗生素具有耐药性。
我们的研究结果表明，INA 细菌种群的流行情况因地点和季节而异。此外，我们的分离株以 A 类和 C 类 INA 细菌为主。本研究还提醒注意 INA 细菌中抗生素耐药性的传播。
