**3.3.2 PFGE Results**

230 Salmonella – A Dangerous Foodborne Pathogen

Serotypes Cattle Human Chicken Ducks Swine Turkey Bison Elk Others Total

(0.2) - 4(0.9)

(bedding) 1(0.2)

207 (47.7)

(17.5)

0)

(lynx)

(0.2) 14(3.2) 434(10

Infantis 2(0.5) 2(0.5) - - - - - - 4(0.9) Java - 1(0.2) - - - - - - 1(0.2) Kentucky - 1(0.2) 2(0.5) - - - - - - 3(0.7) Litchfield - 1(0.2) - - - - - - - 1(0.2) Mbandaka 2(0.5) 2(0.5) - - - - - - - 4(0.9) Mississipi - 1(0.2) - - - - - - - 1(0.2) Montevideo - 3(0.7) - - - - - - - 3(0.7)

Muenster 15 (3.5) - - - - - - - - 15(3.5) Newport 9(2.1) 17(3.9) - - - 2(0.5) - - - 28(6.5) Oranienburg - 2(0.5) - - - - - - - 2(0.5) Paratyphi - 2(0.5) - - - - - - - 2(0.5) Reading - 1(0.2) - - - - - - - 1(0.2) Reno - 1(0.2) - - - - - - - 1(0.2) Sandiego - 2(0.5) - - - - - - - 2(0.5) Senftenberg - - - - - 1(0.2) - - - 1(0.2) Soesterberg - 1(0.2) - - - - - - - 1(0.2) Sonnei - 3(0.7) - - - - - - - 3(0.7) Sovenga - 1(0.2) - - - - - - - 1(0.2) St paul - 7(1.6) - - - 3(0.7) - - - 10 (2.3) Stanley - 1(0.2) - - - - - - - 1(0.2)

Thompson - 1(0.2) - - - - - - 11(0.2)

Typhimurium <sup>140</sup>

Total <sup>193</sup>

North Dakota.

(44.5)

179

Tripoli - 2(0.5) - - - - - - - 2(0.5) Typhi - 1(0.2) - - - - - - - 1(0.2)

Worthingtom 2 (0.5) - - - - - 1(0.2) - - 3(0.7) unidentified 14 (3.2) 47 (10.8) - - - 3(0.7) - - 12(2.8) <sup>76</sup>

Table 8. *Salmonella* serotypes isolated from different animal species and human cases in

The total number of isolates that were common between domestic animals and humans were 183 (42.2%) and 90 (20.7%) respectively (Table 8). *S. Typhimurium* was the predominant serotype in both humans (13.4%, n=58) and domestic animals (34.3%, n= 159), followed by Newport with 11 (2.6%) and 17(3.9%) isolated in animals and human, respectively. *S. Arizona* (n=3, 0.7%)*, S. Give* (n=4, 0.9%) *and S. Muenster* (n=15, 3.5%) were isolated mostly

(32.3) 58 (13.4) - - 3(0.7) 4(0.9) 1(0.2) - 11(0.2)

(41.2) 4(0.9) 1(0.2) 5(1.2) 35(8.1) 2(0.5) <sup>1</sup>

Muenchen - 3(0.7) - - - - - <sup>1</sup>

The initial 434 *Salmonella* isolates were grouped into 113 distinct PFGE profiles at 85% similarity (Tables 9, 10, 11; Figure 2). The 179 human isolates were distributed within the 98 of the 113 PFGE fingerprint patterns or profiles at the same level of similarity. A detailed examination of the 273 isolates from serotypes commonly isolated from man (n=90) and domestic animals (n=183), revealed that 40 of the human and 55 animal isolates were distributed amongst 8 distinct (i.e. with 100% similarity) PFGE fingerprint profiles. The 40 isolates from the human cases were linked to 2 serotypes – *S. Typhimurium Copenhagen* and *S. Heidelberg* that shared indistinguishable genetic fingerprint patterns (100% homology) with some animal isolates. The biggest clonal group involving *S. Typhimurium Copenhagen* with 100 % similarity in the PFGE fingerprint patterns involved 22 isolates from cattle, 17 Humans and 1 from a sick swine (Figure 2). The second PFGE profile involved 19 isolates of *S. Typhimurium Copenhagen* with indistinguishable fingerprints, isolated from 7 feedlot cattle, 2 range cattle and 10 human cases (Figure 2). The third profile had 10 cattle and 4 humans, fifth profile had 1 human, 1 swine and 1 turkey, sixth profile was identified as *S. Heidelberg* form human (1) and turkey meat (1), seventh profile had *S. Typhimurium Copenhagen* from cattle (4), human (5) and chicken (1) and the eighth profile had S. *Heidelberg,* isolated from human (1) and turkey meat (1). Figure 2 shows details of human and domestic animal serotypes in the eight distinct profiles each with indistinguishable PFGE fingerprint patterns. The isolation of serovars with similar PFGE patterns in cattle preceded those in humans. Most outbreaks were recorded in 2004 (58%), while a few turkey isolates with similar PFGE profile were recorded after (Table 9).

Fig. 2. PGFE profile of the commonly serotypes isolated from domestic animals or their products and humans.

Antimicrobial Drug Resistance and Molecular Characterization

*Salmonella* 

Copenhagen

Copenhagen

Copenhagen

Copenhagen

Copenhagen

Copenhagen

*KAN-Kanamycin, STR-Streptomycin, SU-Sulfizoxazole,TET-Tetacycline* 

<sup>I</sup>Typhimurium

II Typhimurium

III Typhimurium

IV Typhimurium

<sup>V</sup>Typhimurium

VII Typhimurium

Xbal patterns with indistinguishable fingerprint

of *Salmonella* Isolated from Domestic Animals, Humans and Meat Products 233

Serotype Origin Antimicrobial resistance

profile

Cattle AM,AMP,CL,STR,SU,TET 20 Cattle AM,AMP,KAN,STR,SU,TET 2 Swine AM,AMP,CL,STR,SU,TET 1 Human AM,AMP,KAN,STR,SU,TET 1 Human CL 4 Human - 5 Human AM,AMP 3 Human GE,STR,SU 1 Human CL,KAN,TET 3

Cattle AM,AMP,CL,STR,SU,TET 8 Cattle AM,AMP,KAN,STR,SU,TET 1 Human - 5 Human CL 4 Human CL,KAN,TET 1

Cattle AM,AMP,CL,STR,SU,TET 10 Human CL 2 Human - 2

Cattle AM,AMP,CL,STR,SU,TET 4 Human - 1

Human CL 1 Swine AM,AMP,CL,STR,SU,TET 1 Turkey meat AM,AMP,CL,STR,SU,TET 1

Turkey meat AMP,CL,SU,TET 1

Turkey meat SU 1

Cattle AM,AMP,CL,STR,SU,TET 4 Chicken AM,AMP,CL,STR 1 Human CX 1 Human CL 1 Human - 2 Human AM,AMP 1

VI Heidelberg Human - 1

VIII Heidelberg Human CL 1

 *Total* 95 *AM-Amoxacillin/Clavulonic acid, AMP-Ampicillin,CX-Ceftixiaxone, CL-Chloramphenicol, GEN-Gentamicin,* 

Table 10. Relationship of molecular types and antibiotic resistance patterns of *Salmonella* 

*enterica* serotype isolated from man, domestic animals and animal products.

Number of matching isolates


Table 9. PFGE profiles, host species and year of isolation of the *Salmonella* serotypes.
