ORIGINAL ARTICLE Occurrence and distribution of multiple antibiotic-resistant Enterococcus and Lactobacillus spp. from Indian poultry: in vivo transferability of their erythromycin, tetracycline and vancomycin resistance Chandran Preethi 1 & Surya Chandra Rao Thumu 1 & Prakash M. Halami 1 Received: 25 December 2016 /Accepted: 1 May 2017 # Springer-Verlag Berlin Heidelberg and the University of Milan 2017 Abstract The objective of this study was to determine the occurrence and distribution of antibiotic resistant (AR) lactic acid bacteria (LAB) in Indian poultry. LAB from poultry farm feces (n = 21) and samples from slaughter houses comprising chicken intestine (n = 46), raw meat (n = 23), and sanitary water (n = 4) were evaluated and compared with those from organic chicken (OC) collected from nearby villages. Screening studies showed 5–7 log units higher erythromycin (ER), tetracycline (TC) and vancomycin (VAN) resistant LAB from conventional poultry chicken (CC) compared to OC. Molecular characterization of isolated cultures (n = 32) with repetitive-PCR profiling and 16S rRNA gene sequencing re- vealed their taxonomical status as Enterococcus faecium ( n = 16), Enterococcus durans ( n = 2) , Lactobacillus plantarum (n = 10), Lactobacillus pentosus (n = 1) and Lactobacillus salivarius (n = 3). The isolates were found to harbor erm(B), msr(C), msr(A/B), tet(M), tet(L) and tet(K) genes associated with Tn916 and Tn917 family transposons. Expression studies through real-time PCR revealed antibiotic- induced expression of the identified AR genes. In vitro and in vivo conjugational studies revealed transfer of ER and TC resistant (ER R and TC R ) genes with transfer frequencies of 10 -7 and 10 -4 transconjugants recipient -1 , respectively. Although no known VAN resistance (VAN R ) genes were de- tected, high phenotypic resistance was observed and was transferable to the recipient. From a public health point of view, this study reports Indian poultry as a major source of high levels of AR bacteria contaminating the food chain and the environment. Thus, urgent and determined strategies are needed to control the spread of multiple AR bacteria. Keywords Antibiotic resistance . Horizontal gene transfer . Poultry . Enterococcus . Lactobacillus Introduction Since the time of their discovery, antibiotics have played a decisive role in human health and life expectancy (Fraqueza 2015). The spectacular success of antibiotics has led to the overuse/misuse of antibiotics in various sectors, such as clin- ical, veterinary, and even food production (Ammor et al. 2008). In intensively raised animals or birds, antibiotics are administered to whole flocks rather than individuals (van den Bogaard et al. 2001). Further, antibiotics may be continuously fed to animals such as broilers as antimicrobial growth pro- moters (Shryock and Richwine 2010). Such exploitation of antibiotics has created selective pressure for the emergence of relatively high amounts of resistant bacteria, raising con- cerns over public health (van den Bogaard et al. 2001). The use of antibiotics induces resistance not only in path- ogenic bacteria but also in endogenous bacterial flora, includ- ing lactic acid bacteria (LAB) (Jacobsen et al. 2007). These bacteria are ubiquitous in nature, and are found to be taxo- nomically diverse. They are found in large numbers in the gatrointestinal tract (GIT) of animals and humans, as well as in fermented dairy and vegetable foods (Thumu and Halami 2012). With the detection of antibiotic resistance (AR) genes in bacteria from food animals and the products derived from them, the food chain has been considered as the main route of transmission of AR (Witte 2000). The spread of resistance Chandran Preethi and Surya Chandra Rao Thumu contributed equally to this work * Prakash M. Halami prakashalami@cftri.res.in 1 Microbiology and Fermentation Technology Department, CSIR-Central Food Technological Research Institute, Mysore 570 020, India Ann Microbiol DOI 10.1007/s13213-017-1270-6