Kubera Łukasz, Rolbiecki Damian, Harnisz Monika, Kotlarska Ewa, Perliński Piotr
Department of Microbiology and Immunobiology, Faculty of Biological Sciences, Kazimierz Wielki University, 85-090, Bydgoszcz, Poland.
Department of Engineering of Water Protection and Environmental Microbiology, Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, 10-719, Olsztyn, Poland.
Environ Pollut. 2025 Mar 1;368:125793. doi: 10.1016/j.envpol.2025.125793. Epub 2025 Feb 3.
The rising incidence of antibiotic resistance poses a significant threat to public health. In recent years the widespread use of antibiotics has led to an increase in the concentration of antibiotic-resistant bacteria also in natural environments. The study was conducted in bathing areas three recreational lakes located in the Zaborski Landscape Park in northern Poland. Water samples were collected in three parallel repetitions in April, June and September 2022. Our study indicates that anthropopressure connected with tourism and recreation promotes the growth of fecal bacteria, including antibiotic-resistant strains, whose significant accumulation was recorded in September, the month marking the end of summer vacation. Antibiotic resistance profiles showed that isolated strains of fecal bacteria were resistant to beta-lactam antibiotics. The highest percentage of Escherichia coli strains showed resistance to cefepime (39.1%), and enterococci to imipenem (26.9%). The amplification of resistance genes confirmed the presence of only selected bla genes in the examined strains of fecal bacteria. The bla gene was found in 14 strains of Enterococcus faecium (82.4%), in all 4 isolates of Enterococcus faecalis, and in 4 out of 5 unspecified strains of fecal streptococci. In Escherichia coli only bla gene was identified in one strain. The presence of bla genes was strongly correlated with the concentration of fecal bacteria, it can therefore be assumed that the presence of resistance genes was caused by direct contamination of the studied lakes with feces containing antibiotic-resistant bacteria, presumably without contamination from other sources. Resistance genes found in the control strains from sewage treatment plants were not identified in the studied isolates. Antibiotic resistance genetic markers found in strains isolated from wastewater may prove helpful in determining the sources of contamination of natural aquatic ecosystems with antibiotic-resistant fecal bacteria and thus ensure efficient management of projects aimed at making these waterbodies available for public use.
抗生素耐药性的不断上升对公众健康构成了重大威胁。近年来，抗生素的广泛使用导致自然环境中抗生素耐药菌的浓度也有所增加。该研究在波兰北部扎博尔斯基景观公园的三个休闲湖泊的浴场区域进行。于2022年4月、6月和9月分三次平行重复采集水样。我们的研究表明，与旅游和娱乐相关的人为压力促进了粪便细菌的生长，包括抗生素耐药菌株，9月份记录到这些菌株大量积累，该月标志着暑假结束。抗生素耐药谱显示，分离出的粪便细菌菌株对β-内酰胺类抗生素耐药。最高比例的大肠杆菌菌株对头孢吡肟耐药（39.1%），肠球菌对亚胺培南耐药（26.9%）。耐药基因的扩增证实，在所检测的粪便细菌菌株中仅存在选定的bla基因。在14株粪肠球菌（82.4%）、所有4株粪链球菌分离株以及5株未明确的粪便链球菌菌株中的4株中发现了bla基因。在大肠杆菌中，仅在一株菌株中鉴定出bla基因。bla基因的存在与粪便细菌的浓度密切相关，因此可以推测，耐药基因的存在是由于研究的湖泊被含有抗生素耐药菌的粪便直接污染所致，大概没有其他来源的污染。在污水处理厂的对照菌株中发现的耐药基因在研究的分离株中未被鉴定出来。从废水中分离出的菌株中发现的抗生素耐药基因标记可能有助于确定天然水生生态系统被抗生素耐药粪便细菌污染的来源，从而确保有效管理旨在使这些水体可供公众使用的项目。
