Anna Zadernowska

Coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food of animal origin – Phenotypic and genotypic antibiotic resistance

The aim of this work was to study the pheno- and genotypical antimicrobial resistance profile of coagulase negative staphylococci (CoNS) isolated from 146 ready-to-eat food of animal origin (cheeses, cured meats, sausages, smoked fishes). 58 strains were isolated, they were classified as Staphylococcus xylosus (n = 29), Staphylococcus epidermidis (n = 16); Staphylococcus lentus (n = 7); Staphylococcus saprophyticus (n = 4); Staphylococcus hyicus (n = 1) and Staphylococcus simulans (n = 1) by phenotypic and genotypic methods. Isolates were tested for resistance to erythromycin, clindamycin, gentamicin, cefoxitin, norfloxacin, ciprofloxacin, tetracycline, tigecycline, rifampicin, nitrofurantoin, linezolid, trimetoprim, sulphamethoxazole/trimethoprim, chloramphenicol, quinupristin/dalfopristin by the disk diffusion method. PCR was used for the detection of antibiotic resistance genes encoding: methicillin resistance--mecA; macrolide resistance--erm(A), erm(B), erm(C), mrs(A/B); efflux proteins tet(K) and tet(L) and ribosomal protection proteins tet(M). For all the tet(M)-positive isolates the presence of conjugative transposons of the Tn916-Tn1545 family was determined. Most of the isolates were resistant to cefoxitin (41.3%) followed by clindamycin (36.2%), tigecycline (24.1%), rifampicin (17.2%) and erythromycin (13.8%). 32.2% staphylococcal isolates were multidrug resistant (MDR). All methicillin resistant staphylococci harboured mecA gene. Isolates, phenotypic resistant to tetracycline, harboured at least one tetracycline resistance determinant on which tet(M) was most frequent. All of the isolates positive for tet(M) genes were positive for the Tn916-Tn1545 -like integrase family gene. In the erythromycin-resistant isolates, the macrolide resistance genes erm(C) or msr(A/B) were present. Although coagulase-negative staphylococci are not classical food poisoning bacteria, its presence in food could be of public health significance due to the possible spread of antibiotic resistance.

Yersinia enterocolitica: A Dangerous, But Often Ignored, Foodborne Pathogen

Yersinia enterocolitica is listed in the annual reports of the European Food Safety Authority (EFSA) as the third-most-common enteropathogen. The highly pathogenic Y. enterocolitica bioserotype 1B/O8 is geographically limited to Northern America, although it has also emerged in Japan and Europe. Furthermore, the number of reports on the pathogenicity of serotype 1A (so far regarded as nonpathogenic) has been increasing. Humans are most often infected by consuming raw or inadequately thermally processed pork or milk as well as vegetable products and ready-to-eat meals. Identification of these bacteria in food presents considerable methodological problems.

Microbiological contamination of dried and lyophilized garlic as a potential source of food spoilage

Garlic is valued more for its flavoring and used in a wide variety of foods. In food technology, fresh garlic is not used, but instead its processed forms, most often dried and lyophilized, are utilized. The quality and safety of the final product largely depends on their microbiological quality. This research has provided information about effect of garlic fixation methods and provided information about effect of microbiological contamination of garlic used as a spice for quality of garlic mayonnaise sauce. The authors decided to undertake studies following a report from one of the manufacturers of garlic sauces on product defects which originated in dried garlic used in the production process. Samples of garlic (n = 26) were examinated using standard cultural methods (counts of fungi, lactic acid bacteria–LAB, spore-producing Bacillus sp. and the presence of anaerobic saccharolytic and proteolytic clostridia), automated system TEMPO (total viable count, Enterobacteriaceae), immunoenzymatic method using VIDAS tests (occurrence of Salmonella sp. and Listeria monocytogenes). The number of total viable count was ranged from 3.51 to 6.85 log CFU/g. Enterobacteriaceae were detected only in one sample. Comparably low values were recorded for fungi (1.30 to 3.47 log CFU/g). The number of LAB was ranged from 2.34 to 5.49 log CFU/g. Clostridium sp. were detected in 22 samples. Salmonella sp. and Listeria monocytogenes were not detected. It was found that garlic, regardless of th preservation procedure, might be a source of contamination of garlic mayonnaise sauce especially with lactic acid bacteria and Clostridium sp. spores.

Staphylococci from food as a reservoir of antibiotic resistance genes

Klebsiella pneumoniae (K. pneumonia), Staphylococcus aureus, Candida albicans and Candida tropicalis are opportunistic microbes associated with certain diseases such as diabetes, deep wounds and immunodeficiency. Those microbes have evolved their resistance to antibiotics in recent years. The aim of this study is to prepare oil extracts from the dried roots of Indian Costus and sea-Qust and test that oils effectiveness on some bacteria and yeast. The results have recorded significantly high antimicrobial activity against K. pneumonia and C.tropicalis during treatment with Indian Costus oil, the sea-Qust oil was also very effective on C.albicans and S.aureus. Because the cell wall (SEM) of C. albicans was rough and wrinkled. Therefore, the budding of yeast became less with a treatment of Indian Costus oil. Thus, this result demonstrates that oil extract of Costus-type plants is effective that their oil extract could be considered as a natural alternative to antibiotics. [Manal Othman Al-Kattan and Amna Ali Saddiq. Study Effect of Indian Costus and Sea-Qust Oil Extract on Some Opportunistic Bacteria and Yeast.. Life Sci J 2014;11(8):423-427]. (ISSN:1097-8135). http://www.lifesciencesite.com. 55W have been using antibiotics for the last so many decades for the therapeutic and animal growth production. There are no stringent laws to minimize the indiscriminate use of antibiotics. Inappropriate usage of antibiotics has led to many problems, mainly antibiotics resistance and residues in veterinary sector. More than 70% of the antibiotics are being used in animal sector for the growth production by the persons who are not having any knowledge about antibiotics. For the last three decades, there has been no major approval for new antibiotics. We have to focus on preserving the current antibiotics for the future generations. There is no scientific base for the usage of antibiotics in India. Even an ordinary layman gets antibiotics over the counter without any prescription. At this juncture it is the responsibility of each and every individual of this country to use antibiotics in a rational and legitimate use. In this regard, author would like to present his views of comprehensive strategies to be adopted for changing norms for reducing unnecessary and inappropriate use of antibiotics in India.T increase of community-associated and hospital-acquired infections with Staphylococcus aureus accompanying with the raise of antibiotic resistant isolates particularly multi-drug resistant (MDR) ones recently has become a serious clinical and epidemiological problem. In this study, 51 S. aureus isolates obtained from healthy volunteers in Southern Vietnam were analyzed in order to determine their drug susceptibility to twelve commonly used antibiotics including ampicillin, cefoxitin, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, kanamycin, linezolid, meropenem, rifampin, tetracycline and trimethoprim/ sufamethxazole by using disc diffusion technique. The resistant rate of S. aureus isolates to vancomycin was also determined by using minimum inhibitory concentration method. Antibiotic sensitivity test demonstrated that most of the isolates were resistant to ampicillin (96.08%). Meanwhile the resistant rates to clindamycin, kanamycin, erythromycin, linezolid, tetracycline and ciprofloxacin were in the range of 28%-61%. In addition, few antibiotics still have strong effect on S. aureus such as cefoxitin (resistant rate15.69%), meropenem (13.73%) chloramphenicol (5.88%), trimethoprim/sufamethxazole, rifampin (1.96%) and particularly vancomycin (0%). Moreover, the rate of MRSA in southern Vietnam community is estimated via cefoxitin resistant percentage which is around 16%, doubled the rate announced in 2004. In conclusion, the data provided essential information on the antibiotic susceptibility profile of S. aureus isolates in Vietnamese community.

STAPHYLOCOCCUS AUREUS FROM READY-TO-EAT FOOD AS A SOURCE OF MULTIPLE ANTIBIOTIC RESISTANCE GENES

The emergence of antibiotic-resistant strains of S. aureus such as methicillin-resistant S. aureus (MRSA) is a worldwide problem. Ready-to-eat (RTE) food which does not need thermal processing before consumption could be a vehicle for the spread of antibiotic-resistant microorganisms. The present study evaluated the molecular genetic characteristics (RAPD) and pheno- and genotypical antimicrobial resistance profile of S. aureus isolated from 75 RTE food samples (sushi, hamburgers, salads). All of the isolates (n=32) were resistant to at least one class of antibiotic tested of which 75% strains were classified as multidrug resistant. Most of the isolates were resistant to cefoxitin (87,5%) followed by clindamycin (78,1%), tigecycline and quinupristin/dalfopristin (53,1%). All methicillin resistant staphylococci harbored mec A gene. Among tetracycline resistance isolates all of them harbored at least one gene: tet (M), tet (L) and/or tet (K) and 78,9% of them were positive for the Tn 916 /Tn 1545 -like integrase family gene. Our results indicated that retail RTE food could be considered an important route for transmission of antibiotic resistant staphylococci harboring multiple antibiotic resistance genes.