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DANMAP 2015 3D
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71 danmap 2015 6.
resistance
in zoonotic bacteria 6.1.2 s .
typhimurium
in pigs, domestically produced and imported pork a total of 89 s .
typhimurium
(including monophasic strains) were isolated from danish pigs and pork. of these 27 were generic
typhimurium
and 62 monophasic, which continued the historic increasing trend of the proportion of monophasic isolates, illustrating the spread of these novel serotypes. the level of fully sensitive s .
typhimurium
isolates in both pig and pork in 2015 remained similar to the level in 2014 (17% and 20%, respectively). no important differences in
resistance
levels were found between s .
typhimurium
isolates from pig and pork (table 6.2) and
resistance
to the tested antimicrobial agents was similar to levels reported in 2014. as in the previous years, the highest
resistance
levels were observed to ampicillin, tetracycline and sulfamethoxazole. the occurrence of asut multi-
resistance
has been increasing among s .
typhimurium
from pigs since 2010, partly due to an increase in the occurrence of the monophasic variants of s .
typhimurium
, which often carry the asut multi-
resistance
(figure 6.3). this year 63% of the monophasic isolates carried asut mostly in combination with
resistance
to one or more antibiotics, whereas the asut- profile only was seen in 32% of the generic
typhimurium
isolates. the increasing occurrence of multi-resistant monophasic s. 4,[5],12:i:- is also happen- ing in europe [hopkins et al. 2010. eurosurveillance 3:1]. this illustrates how spread of antimicrobial
resistance
among salmonella can be highly influenced by the spread a multi- resistant clones highlighting the multifactorial causes of global antibiotic
resistance
. tetracyclines, beta-lactamase sensitive penicillins, pleuromutil- ins and macrolides (mainly tylosin and tilmicosin) are the main antimicrobial agents used for weaners and pigs in denmark (figure 4.4). the use of tetracycline and to some extent macrolides increased from 2004 to 2009, where after the consumption was reduced over the following years. however these changes in usages of tetracycline and macrolides is not reflected in the observed levels of
resistance
in s.
typhimurium
from pigs and domestically produced pork (figure 6.3) ? as the trends is dominated by the increasing occurrence of monophasic s. 4,[5],12:i:- clones. none of the s.
typhimurium
isolates from pigs or pork were re- sistant to quinolones (ciprofloxacin or nalidixic acid), cephalo- sporins (cefotaxime and ceftazidime) or carbapenems (merope- nem); and the use of flouroquinolones and cephalosporins in the danish pig production has been very low for at last decade (web annex , table a4.2) . two s.
typhimurium
(one of these monophasic) isolates were resistant to azithromycin (assuming the cutoff mic>16), one originating from live pigs and one from pork. in both
cases
, the isolates also carried an asut-profile. 6.1.3 salmonella in humans in 2015, salmonella continued to be the second most frequent cause of bacterial intestinal infections in denmark. a total of 925 human laboratory-confirmed
cases
of salmonellosis was reported (16.3
cases
per 100,000 inhabitants). the most com- mon serotypes were s.
typhimurium
(including the monophasic variants) and s. enteritidis with 4.1 and 4.6
cases
per 100,000 inhabitants, respectively [annual report on zoonoses in den- mark 2015]. 6.1.4 s.
typhimurium
in humans s .
typhimurium
, including the monophasic variants, was the second most common serotype among the human
cases
(233
cases
), s. enteritidis being the most common (259
cases
).the monophasic variants represented half the s .
typhimurium
cases
(117 monophasic versus 116 generic
typhimurium
). available isolates were susceptibility tested (n = 231). information on travel history was collected through phone interviews, and among the reported human s .
typhimurium
isolates included in danmap 2015, 29% of the
cases
were categorised as travel associated, whereas 56% most likely had acquired their infection in denmark (table 6.2). in 2015, only one outbreak with the monophasic variant of s .
typhimurium
was detected and only 6 human
cases
were considered ?outbreak-related?. in contrast to previous years, domestically acquired human
cases
includes sporadic as well as out-break related
cases
(table 6.2). again this year, high levels of
resistance
to ampicillin, sulfon- amide, and tetracycline were observed.
resistance
to ampicil- lin was observed at the same level (65-67%) among isolates from domestic and travel-associated
cases
(table 6.2). for domestically acquired
cases
the level of ampicillin
resistance
had increased significantly from 2014 to 2015 (from 54% to 65%).
resistance
to sulfonamide and tetracycline increased significantly in travel associated
cases
from 2014 to 2015, where 76% and 74% were resistant in 2015 respectively. overall, 48% of all s .
typhimurium
isolates carried the asut multi-
resistance
profile (n = 112) alone or in combination with other antimicrobials. comparison with previous years showed that the proportion of isolates resistant to these antimicrobial agents have stabilised at this fairly high level. the level of
resistance
to trimethoprim increased in domestically acquired
cases
from 2014 to 2015 (6% to 14%, including both sporadic and outbreak related
cases
) reaching the same level as for travel-associated
cases
(11% in 2015). there is a tendency for higher levels of
resistance
among travel-associated isolates compared with domestic infections in 2015. both ciprofloxacin and nalidixic acid
resistance
were higher in isolates from travel-related
cases
(20% and 8% respectively) compared with isolates from domestic
cases
(2% for both antibiotics).
resistance
to both tetracycline and gentamicin were also significantly higher in travel-associated
cases
(74% and 11% respectively) when compared to do- mestically acquired
cases
(55% and 1% respectively). finally,
resistance
to chloramphenicol increased significantly in both
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