Prevalencija, antibiotska rezistancija i sposobnost stvaranja biofilma bakterija Enterococcus spp. izoloiranih iz prehrambenih proizvoda u Alžiru

Enterococci are ubiquitous bacteria in the normal intestinal microbiota of both humans and animals. They can be used in the food industry as starter or probiotic cultures. However, some species have emerged as an important nosocomial pathogens, and have been implicated in severe multi-resistant infections. In this study, a total of 235 food products were analyzed for the presence of Enterococcus spp. Overall, 54 (22.9%) out of the 235 samples were contaminated and 54 strains were isolated. The latter were identified by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and tested for antibiotic susceptibility against seven antibiotic molecules, in addition to their ability to form a biofilm. The predominant species was Enterococcus faecalis (70.4%), followed by Enterococcus hirae (12.9%), Enterococcus faecium (11.1%) and Enterococcus durans (5.5%). The highest resistance profile was ascribed to tetracycline (66.7%) and penicillin G (33.3%). Six enterococcal isolates (11.1%) were resistant to at least three antibiotic families. All isolated strains were able to form a biofilm and exhibited gelatinase activity. However, only 4 (7.4%) were β-hemolytic. This study revealed that food products might play a role in the spread of enterococci through the food chain to humans with these virulence and resistance characteristics. As a result, continuous investigations are necessary to assess the health hazards associated with the consumption of contaminated food products.Enterokoki su ubikvitarne bakterije u fiziološkoj crijevnoj mikrobioti ljudi i životinja. Mogu se upotrijebiti u prehrambenoj industriji kao starterna ili probiotička kultura, međutim neke su se vrste pojavile kao važni nozokomijalni patogeni povezani s teškim multirezistentnim infekcijama. U ovom je istraživanju ukupno 235 prehrambenih proizvoda analizirano na prisutnost enterokoka. Od navedenog broja, 54 uzorka (22,9 %) bila su kontaminirana te su izolirana 54 soja. Potonji su identificirani masenom spektofotomerijom temeljenoj na MALDI-TOF (engl. Matrix Assisted Laser Desorption/Ionization Time-of-Flight) tehnologiji te je analizirana osjetljivost na sedam molekula antibiotika kako bi se potvrdila sposobnost stvaranja biofilma. Prevladavajuće su vrste bile Enterococcus faecalis (70,4 %), zatim Enterococcus hirae (12,9 %), Enterococcus faecium (11,1 %) i Enterococcus durans (5,5 %). Te su vrste najveću rezistenciju pokazale na tetraciklin (66,7 %) i penicilin G (33,3 %). Šest izolata enterokoka (11,1 %) bilo je rezistentno na najmanje tri porodice antibiotika. Svi su izolirani sojevi bili sposobni stvoriti biofilm i pokazali su aktivnost želatinaze, no samo su četiri soja (7,4 %) bila β-hemolitička. Ovo je istraživanje pokazalo da se enterokoki s ovakvom virulencijom i svojstvima rezistencije na antibiotike mogu širiti putem prehrambenih proizvoda. Potrebna su stoga kontinuirana istraživanja kako bi se procijenili zdravstveni rizici povezani s uzimanjem hrane kontaminirane bakterijama roda Enterococcus spp

Fizikalno-kemijske karakteristike i detekcija rezidua antibiotika u sirovom kravljem mlijeku isporučenom u tri industrije za preradu mlijeka u Alžiru

The uncontrolled use of antimicrobials in veterinary medicine may result in the presence of their residues in food matrices of animal origin such as milk. The aim of this study was to examine the physicochemical quality and to detect antibiotic residues (β-lactams and tetracyclines) in milk, as their presence has resulted in the rejection of significant quantities of milk for marketing. The study was conducted on 274 milk samples delivered to three milk-processing units located in the suburbs of Algiers and surrounding cities (Blida and Boumerdes). Antibiotic residue detection was performed using a fast screening test (BetaStar® Combo), with a reading result within five minutes. The results indicated that the milk processing industry of Blida had the highest rejected milk volumes (43.4%), followed by Algiers (24%) and Boumerdes (19.1%). Non-compliance of milk acidity was the first cause for milk rejection (47.6 %), followed by the presence of antibiotic residues (26.8%), and incompliance with requirements for density (13.4%) and fat levels (12.2%). The study revealed 22 positive cases (8.03%) of antibiotic residues. Among these, 90.91% were positive for β-lactams, and only 9.09% for tetracyclines. All tetracyclines cases and half of the β-lactams cases were found in the Blida milk processing company, indicating that the good practice of milk production and collection must be strengthened in that company.Nekontrolirana uporaba antimikrobnih sredstava u veterinarskoj medicini može rezultirati prisustvom njihovih rezidua u matricama hrane životinjskog podrijetla kao što je i mlijeko. Ovaj rad ima za cilj proučavanje fizikalno-kemijske kakvoće i detekcije ostataka antibiotika (β-laktama i tetraciklina), čije je određivanje u mlijeku prouzročilo odbijanje znatnih količina za plasman na tržištu. Istraživanje je provedeno na 274 uzorka mlijeka dostavljena u tri jedinice za preradu mlijeka koje se nalaze u predgrađima Alžira i drugih gradovima (Blida i Boumerdes). Detekcija ostataka antibiotika provedena je brzim testom (BetaStar® Combo), s rezultatom očitanja unutar pet minuta. Rezultati su pokazali da je najveća količina odbijenog mlijeka u industriji prerade mlijeka iz jedinice Blida (43,4 %), a slijede Alžir (24 %) i Boumerdes (19,1 %). Nesukladnost kiselosti mlijeka bila je prvi uzrok odbacivanje mlijeka (47,6 %), a zatim slijede: prisutnost antibiotskih ostataka (26,8 %), gustoća (13,4 %) i nesukladnost razine masti (FL) (12,2 %). Od svih procijenjenih uzoraka, studija je otkrila 22 pozitivna slučaja (8,03 %) na ostatke antibiotika. Među njima je 90,91 % bilo pozitivno na β-laktame, dok je samo 9,09 % pozitivno na tetracikline. Svi slučajevi tetraciklina i polovica β-laktama pronađeni su u mljekoprerađivačkoj tvrtki Blida, što ukazuje da se u toj kompaniji mora ojačati dobra praksa uzgoja i prikupljanja mlijeka

Role of milk and milk products in the spread of methicillin‐resistant Staphylococcus aureus in the dairy production chain

International audienceMilk and milk products can harbor a multiple varieties of microorganisms. Therefore, they can be an important source of foodborne pathogens, including multidrug-resistant bacteria. Methicillin-resistant Staphylococcus aureus (MRSA) causes a wide spectrum of infections both in animals and humans. Over the last two decades, the presence of MRSA in foods and food-producing animals, including milk and milk products, has been frequently reported worldwide, raising public health concerns. In order to monitor and prevent foodborne MRSA contamination, it is necessary to understand their sources, the pheno/genotypic characteristics of the strains, and their transmission dynamics. In this review, studies conducted worldwide were summarized in order to assess the prevalence and diversity of MRSA circulating in milk and milk products. The risk factors for the occurrence of MRSA in milk and milk products were also discussed with preventive and control measures to avoid MRSA contamination in the dairy food chain

Free fatty acid profiles and cholesterol and lipid indexes of raw ewe's milk from two Algerian breeds (Ouled-Djellal and Rumbi), collected in the steppe area

Description of the subject. This article aims to characterize the fat content of raw ewe's milk, collected locally in the Algerian central steppe, an area highly appreciated for its production of smen (traditional butter). Objectives. The objective of this study was to investigate the free fatty acid profile and the cholesterol and lipid indexes of raw ewe's milk from two Algerian local breeds (Ouled-Djellal and Rumbi). Method. Milk was collected from 20 ewes of each breed three times during the middle stage of lactation. The milk fat was extracted using the Rose-Gottlieb method. Fatty acids were analyzed by gas chromatography. Results. Palmitic (24.4% +/- 3.3), oleic (24.2% +/- 4.6), stearic (10.8% +/- 3.5), myristic (10.4% +/- 1.9) and capric (8.3% +/- 3.5) acids dominated and accounted for 78.1% of the total fatty acids. Saturated fatty acids predominated compared to unsaturated fatty acids (69.6% +/- 5.3 vs 30.8% +/- 5.1), and monounsaturated fatty acids outweighed the polyunsaturated (26.3% +/- 4.7 vs 4.5% +/- 1.1). The Ouled-Djellal milk had a higher short-chain fatty acid content than the Rumbi milk (p < 0.05). On the other hand, the Rumbi milk was richer in medium chain fatty acids. The two types of milk differed significantly regarding their palmitic and palmitoleic acid content (p < 0.05). Within the long chain of fatty acids, only the stearic acid (10.88% +/- 2.83 vs 12.34% +/- 2.75; p < 0.01) and the arachidic acid (0.26% +/- 0.18 vs 0.35% +/- 0.09; p < 0.05) were influenced by the breed. Conclusions. Results showed that milk from the Rumbi ewe was richer in fatty acids than the milk from the Ouled-Djellal and that Rumbi ewe's milk may be of value in dairy technology due to the socio-economic impact that it can generate

Phenotypic and Genotypic Characterization of <i>Staphylococcus aureus</i> Isolated from Nasal Samples of Healthy Dairy Goats in Algeria

The present study aimed to determine the phenotypic and genotypic characteristics of S. aureus isolates from the nasal swabs of goats. A total of 232 nasal samples (one per animal) were collected from goats on 13 farms located in two regions of Algeria and were analyzed for the presence of S. aureus. The detection of virulence factors was carried out using PCR. The antibiotic susceptibility of the recovered isolates was assessed using the disc diffusion method. The biofilm formation ability was assessed by the Congo red agar method and a microtiter plate assay, and the molecular characterization of isolates was carried out by spa-typing, and for selected isolates also by multilocus sequence typing (MLST). Overall, 36 out of 232 nasal swabs (15.5%) contained S. aureus, and 62 isolates were recovered. Regarding the virulence factors, at least one staphylococcal enterotoxin gene was detected in 30 (48.4%) isolates. The gene tst encoding the toxic shock syndrome toxin was detected in fifteen isolates (24.2%), but none of the isolates harbored the gene of Panton–Valentine leukocidin (lukF/S-PV). Nine different spa-types were identified, including the detection of a new one (t21230). The recovered isolates were assigned to three clonal complexes, with CC5 (51.8%) being the most common lineage. Two isolates were methicillin-resistant (MRSA) and belonged to ST5 (CC5) and to spa-types t450 and t688. Moreover, 27 (43.5%) of the S. aureus isolates were found to be slime producers in Congo red agar, and all of the recovered isolates could produce biofilms in the microtiter plate assay. Our study showed that the nares of healthy goats could be a reservoir of toxigenic and antibiotic-resistant strains of S. aureus isolates, including MRSA, which could have implications for public health