# The Invisible Threat of Antibiotic Resistance in Food
## 3 Antibiotic Resistance in Traditional Foods
### Antibiotic Resistance in Vegetables and Fruits
A variant of the _shv_ gene (_blaSHV-110_) was identified by [PERSON] et al. [56] in _Klebisiella pneumonine_ isolates from orange samples obtained from Chinese markets. Similarly, [PERSON] et al. [180] reported the presence of the same gene in three isolates from an orange juice sample. A German study [181] reported the isolation of seven ESBL-producing _E. coli_ isolates from fresh vegetables. The isolates were positive for _blaCTX-M-14_, _blaCTX-M-15_, _blaCTX-M-65_, _blaCTX-M-125_, and _blaCTX-M-2_ genes. [PERSON] et al. [182] documented the occurrence of multidrug-resistant _Klebisiella pneumonia_ isolates including ESBL genes in fresh fruits and vegetables sold in Algerian markets. The study of [PERSON] et al. [183] from China revealed that of the 48 _E. coli_ isolates, 28 (58.3%) were identified as ESBL-producing. Of these, 4 (66.7%, 4/6) were collected from soil, 6 (40.0%, 6/15) from vegetables, and 18 (66.7%, 18/27) from irrigation water. Chinese resistance surveillance data conducted in 2021 indicated a significant increase in the proportion of ESBL-producing _E. coli_, reaching 52.6% [184]. A high prevalence (83.3%; 20/24) of ESBL-producing strains from fresh vegetables and RTE salads [185] was published concerning Italian fresh produce. In contrast, there was a much lower frequency of ESBL-positive isolates in products tested in South Korea [176]. Among the analyzed 1324 raw vegetable samples, 0.83% (11/1324) were ESBL-positive _E. coli_ strains. [PERSON] and [PERSON] [177] published a paper on variants of ESBL resistance in _L. monocytogenes_ strains from fruits and vegetables in South Africa besides _L. monocytogenes_ isolates, that encoded resistance to a range of other antibiotics, including tetracyclines, sulfonamides, phenicols, and aminoglycosoides. The first report on _mcr-1_-producing _E. coli_ isolated from fresh produce was published in Switzerland in 2016 from ready-to-eat vegetables grown in Thailand and Vietnam. The two isolates were found to carry the _mcr-1_ gene together with the _blaCTX-M-5_ and _blaCTX-M-65_genes [186]. Since the first isolation, _mcr_ gene-producing Gram-negative bacteria have been reported worldwide [53; 187; 160; 56; 188]. In South Korea, [PERSON] et al. [189] identified the _mcr-1_ gene in _E. coli_ isolates from 0.076% (1/1324) of the investigated vegetable samples. The presence of the gene-encoding _mcr-1_ plasmid-mediated colistin resistance was reported in an _E. coli_ isolated from lettuce grown and marketed in Portugal [187]. In a study conducted by [PERSON] et al. [53], the authors analyzed _mcr_ genes in 528 vegetable samples sourced from 53 supermarkets or farmers' markets across 23 cities in nine provinces in China. Twenty-three _E. coli_ and one _Enterobacter cloacae mcr-1_-positive isolate were obtained, which were derived from 19 (3.6%) vegetable samples. Fruit samples from China have also shown the presence of _mcr_ genes [56]. This study conducted an examination of 133 fruit samples to determine the presence of various MCR variants (_mcr-1_ to _mcr-8_). This finding revealed the first identification of _mcr-1_-carrying _E. coli_ and _Klebsiella pneumoniae_ in market retail fruits in Guangzhou, China. In Japan, 308 colistin-resistant isolates were detected in 200 fresh vegetable samples [188]. Despite the absence of positive _mcr-1_ to _mcr-8_ genes among the isolates, one _Enterobacter cloacae_ strain and a _Raoultella ornithinolytica_ were identified as positive for the _mcr-9.1_ allele. The first Algerian report of the detection of the _mcr-1_ gene from vegetables was published by [PERSON] et al. [190]. From the analyzed 400 fresh vegetable samples, the _mcr-1_ gene was detected in only two _E. coli_ isolates. The first publication of carbapenemase-producing _Klebsiella variticola_ from fresh vegetable samples was published in 2015 [191]. The isolated strain was positive for the _blaOXA-181_ gene. It was isolated from a coriander sample from Thailand/Vietnam.