Antibiotic resistance profiles and integrons in Enterobacteriaceae from the riverside of Evros-Ardas with respect to chemical and waste pollution

Figures & data

Figure 1.  Sampling stations at the Ardas and Evros rivers in the Evros region of Greece.

Figure 2.  Mean concentration of indicator bacteria following the physical flow of the Ardas and Evros rivers to the sea (from north to south).

Table I.  Mean concentration of indicator bacteria at all sampling stations (n = 118).

			Mean concentration* (cfu/100 ml)
ID	River	Sampling station	Total coliforms	E. coli
S1	Ardas	Komara	380	80
S2	Ardas	Elaia	400	120
S3	Ardas	Rizia	410	130
S4	Ardas	Kastanies	600	170
S5	Evros	Dikaia	500	220
S6	Evros	N. Vissa	5800	5200
S7	Evros	Didimoticho	6100	5500
S8	Evros	Lagina	6600	5580
S9	Evros	Kipoi	7100	5820

* From log transformed values.

Table II.  Mean concentration of chemical parameters at all sampling stations (n=118).

ID	Sampling station	pH	Conductivity levels (µS/cm)	NO3 (mg/l)	NO2 (mg/l)	SO4 (mg/l)	PO4 (mg/l)	Zn (µg/l)	Cu µg/l	Fe (µg/l)
S1	Komara	7.8	210	0.5	0.026	44	0.20	ND	ND	12.1
S2	Elaia	7.8	320	0.9	0.022	42	0.19	ND	ND	12.4
S3	Rizia	7.7	350	0.9	0.023	38	0.16	ND	ND	12.9
S4	Kastanies	7.5	260	1.3	0.023	39	0.18	ND	ND	14.5
S5	Dikaia	7.7	330	1.8	0.099	73	0.68	ND	ND	6.0
S6	N. Vissa	7.7	360	1.1	0.082	78	0.65	ND	1.9	6.4
S7	Didimoticho	7.8	560	3.5	0.056	78	0.86	ND	2.5	7.1
S8	Lagina	7.8	620	4.5	0.124	77	1.10	ND	ND	8.8
S9	Kipoi	7.8	880	6.6	0.074	73	0.92	ND	ND	9.5

ND, not detectable.

Table III.  Antibiotic resistance profiles of integron class I and II and gene cassettes of 14 strains isolated in ecosystems of Ardas and Evros.

E. coli strains	Integron class I	Integron class I antibiotic gene cassette	Integron class I + II	Antibiotic resistance profile
1	+	1600 bp	–	sul, tri, strep, tet, chlor
2	+	1600 bp	–	sul, tri, strep, amp, amx, amx + clavulanic acid, tet, chlor
3	+	–	+	sul, amp, amx, amx + clavulanic acid,
4	+	–	+	sul, amp, amx, amx + clavulanic acid, cefotaxime, cefoxitin, nal, norfloxacin, ciprofloxacin
5	–	–	–	nal, ciprofloxacin, norfloxacin
6	–	–	–	amp, amx amx + sulbactam, cefotaxime, cefpirone, cefoxitin, norfloxacin, ciprofloxacin
7	–	–	–	amp, amx amx + sulbactam
8	–	–	–	amp, amx, tet
9	–	–	–	amp, amx, amp + clavulanic acid
10	–	–	–	amp, amx
11	–	–	–	amp, amx, nal
12	–	–	–	amp, amx
13				amp, amx, amp + clavulanic acid
14	–	–	–	amp, amx, chlor

+, presence; –, absence; amp, ampicillin; amx, amoxicillin; chlor, chloramphenicol; nal, nalidixic acid; strep, streptomycin; sul, sulfamethoxazole; tet, tetracycline; tri, trimethoprim.