Antimicrobial Resistance and Heat Sensitivity of Oxacillin-Resistant, mecA-Positive Staphylococcus spp. from Unpasteurized Milk

2008 ◽  
Vol 71 (1) ◽  
pp. 186-190 ◽  
Author(s):  
ALAN M. MCKAY

Eight Staphylococcus spp. carrying the mecA gene were isolated from oxacillin enrichments of 70 unpasteurized milk samples. The isolates were identified as five Staphylococcus epidermidis, two Staphylococcus lentus, and one Staphylococcus haemolyticus. No mecA-positive Staphylococcus aureus were isolated. All isolates carried genes for other antibiotic resistances in addition to mecA. The results establish that mecA-carrying coagulase-negative Staphylococcus spp. in unpasteurized milk have the potential to be a reservoir of other genes encoding antimicrobial resistance. Two S. epidermidis isolates with qacA/B genes were resistant to benzalkonium chloride. Decimal reduction times (D-values) for the mecA-Staphylococcus spp. at 56°C in whole milk ranged from 1.46 to 2.82 min. D-values at 56°C for nine S. aureus milk isolates ranged from 10.8 to 20.1 min. Heat treatments intended to control S. aureus may be an effective means to protect consumers of milk and dairy products. Contact with or consumption of milk and dairy products that have not been heat treated may lead to the spread of antimicrobial resistance genes in Staphylococcus spp. to animals and humans.

Author(s):  
Anil Poudel ◽  
Terri Hathcock ◽  
Patrick Butaye ◽  
Yuan Kang ◽  
Stuart Price ◽  
...  

Background: Antimicrobial resistance is rising globally at an alarming rate. While multiple active surveillance programs have been established to monitor the antimicrobial resistance, studies on the environmental link to antimicrobial spread are lacking. Methods: A total of 493 flies were trapped from a dairy unit, a dog kennel, a poultry farm, a beef cattle unit, an urban trash facility and an urban downtown area to isolate Escherichia coli, Klebsiella pneumoniae and Staphylococcus spp. for antimicrobial susceptibility testing and molecular characterization. Results: E. coli, K. pneumoniae and coagulase-negative Staphylococcus were recovered from 43.9%, 15.5% and 66.2% of the houseflies, and 26.0%, 19.2%, 37.0% of the blowflies, respectively. In total, 35.3% of flies were found to harbor antimicrobial-resistant bacteria and 9.0% contained multidrug-resistant isolates. Three Staphylococcus aureus isolates were recovered from blowflies while three extended spectrum beta lactamase (ESBL)-carrying E. coli and one ESBL-carrying K. pneumoniae were isolated from houseflies. Whole genome sequencing identified the antimicrobial resistance genes blaCMY-2 and blaCTXM-1 as ESBLs. Conclusion: Taken together, our data indicate that flies can be used as indicators for environmental contamination of antimicrobial resistance. More extensive studies are warranted to explore the sentinel role of flies for antimicrobial resistance.


2017 ◽  
Vol 68 (11) ◽  
pp. 2546-2550
Author(s):  
Monica Licker ◽  
Andrei Anghel ◽  
Roxana Moldovan ◽  
Elena Hogea ◽  
Delia Muntean ◽  
...  

Antimicrobial resistance (AMR) represents a real burden for the modern medicine. One of the most frecvently isolated hospital acquired (HA) pathogens wordlwide, is Methicillin resistant Staphylococcus aureus (MRSA). Recently not only HA, but also community-acquired MRSA (CA-MRSA) infections have been reported. A prospective study was performed between February 2009 and October 2010, with the aim to investigate bacterial resistance of CA-MRSA and HA-MRSA. DNA microarray technology has been used for the detection of 4 AMR genes for the studied MRSA strains. A number of 218 HA- S.aureus strains have been isolated, from which 89 (40. 82%) were MRSA. In the community, 1.553 S.aureus strains were isolated, out of which, 356 (22. 92%) were MRSA. From these, a number of 17 HA and 12 CA �MRSA strains have been analyzed by DNA microarray technology. From 100% phenotypically described HA- MRSA, we identified mecA gene in 10 strains (58. 83%). Other 6 strains (35. 29%) have been erm(A) positive and 4 (23. 53%) - tet(O) positive. 83. 33% (10 strains) from the CA strains had mecA gene, only one (8. 33%) was erm(A) positive and 4 (33. 33%) were erm(C) positive. DNA microarray is a method allowing the concomitant scan of multiple genes and can be done within a few hours. That type of rapid and reliable methods for antimicrobial sensitivity tests are important to start an appropriate therapy.


2020 ◽  
Vol 48 ◽  
Author(s):  
Érica Chaves Lucio ◽  
Gisele Veneroni Gouveia ◽  
Mateus Matiuzzi Da Costa ◽  
Mário Baltazar De Oliveira ◽  
Rinaldo Aparecido Mota ◽  
...  

Background: Bovine mastitis remains one of the health problems that cause the most damage to milk producers. The negative impact of mastitis is due to reduced milk production, early slaughter of females, reduced commercial value of the affected animals, losses in the genetic potential of the herd, expenses with medicines and veterinary medical assistance. Staphylococcus spp. stands out as the cause of this disease and has been able to remain in the mammary gland, becoming resistant to several antimicrobials. The aims of the present study were to characterize the phenotypes, genotypes and resistance profiles of Staphylococcus spp. isolates from bovine mastitis cases in the state of Pernambuco, Brazil.Materials, Methods & Results: These isolates were classified according to biochemical tests and the presence of the nuc gene.  The polymerase chain reaction (PCR) for amplification of the mecA and blaZ genes was used to analyze the genetic potentials of antimicrobial resistance. Isolates were also phenotypically tested for resistance to nine antimicrobials (ampicillin, doxicillin, erythromycin, gentamicin, rifampicin, cephalothin, amoxicillin, nalidixic acid and oxacillin). The genetic potentials for biofilm production were evaluated by the amplifications of the icaD, icaA and bap genes. The phenotypic test of gentian violet was used for biofilm formation analyzes. Ninety-three (93.0%) of the isolates among the Staphylococcus spp. samples were classified as Staphylococcus aureus. The lowest percentage of sensitivity observed was for amoxicillin (28.0%). All of the isolates were sensitive to erythromycin and gentamicin, and 15 (15%) exhibited sensitivity to all of the drugs tested. All of the isolates were negative for the mecA gene, and 36 (36%) were positive for blaZ. In the adhesion microplate tests, 44 (44%) of the isolates were capable of biofilm formation. Of these, seven (15.9%) were strong formers, whereas 16 (36.3%) and 21 (47.8%) were moderate and weak formers, respectively. The icaD gene was confirmed in 89 (89%) of the isolates. The icaA gene was confirmed in 61 (61%) samples, and the bap gene in 52 (52%) samples. One of the samples did not possess icaA, icaD or bap and exhibited moderate biofilm formation according to the microplate adherence test. Sixteen isolates simultaneously exhibited the three genes tested for biofilm production (icaA, icaD and bap) and were negative according to the microplate adherence test.Discussion:  The indiscriminate use of antibiotics to treat mastitis is a common practice in the study area, which may have contributed to the high proportion of herds (88.23%; 15/17) with multi-resistant isolates, constituting a selection factor for the dissemination of resistant bacteria among herds.  The absence of the mecA gene in the present study may be associated with the development of resistant bacteria through another mechanism, such as the overproduction of beta-lactamases. The results demonstrate that antimicrobial resistance occurs in Staphylococcus spp. that cause bovine mastitis in herds of Pernambuco and that these isolates have the a great capacity for biofilm formation. It is necessary to sensitize the professionals involved in the milk production chain of Brazil regarding the importance of the adequate use of antimicrobials for the treatment and control of mastitis, since studies in the country indicate the dissemination of resistant bacterial strains.


2015 ◽  
Vol 143 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
Anka Popovic-Vranjes ◽  
Milka Popovic ◽  
Marija Jevtic

Contrary to the safe practices of milk pasteurization or sterilization, which effectively reduce foodborne outbreaks incidence associated with raw milk and dairy products use, outbreaks caused by such products continue to occur. Despite this fact, a worldwide movement advocating for the rights of raw milk and cheese selling and consumption, due to their specific nutritive characteristics, has strengthened significantly in recent years. Traditional agricultural manufacturers from Serbia still sell products related to thermally unprocessed milk, such as cottage cheese and raw cream. In AP Vojvodina during the period of 1981-2010 a total of 179 foodborne outbreaks were reported, where the incriminated cause of the outbreak were milk or diary. In 126 (70.39%) outbreaks, totaling 2276 sick individuals and one casualty, it was confirmed that the incriminated food was from the group of dairy products. In 48 instances (26.82%), bacteriological tests confirmed that milk and dairy products were excluded as the outbreak causes, while in another 5 (2.79%) outbreaks, microbiological analysis of food failed to confirm any relation to the actual epidemiological instances. In some cases, bacteriological testing of incriminated foods was not possible. In the cases of outbreaks associated with the consumption of milk and dairy products, traditional raw milk products were cited as being used. Consumption of unpasteurized milk and cheese represents public health threat. National and international rules ensuring use of safe products for human consumption have to set rules of trade of thermally processed milk and products on the market.


2020 ◽  
Vol 83 (7) ◽  
pp. 1110-1114 ◽  
Author(s):  
MARGARIDA SOUSA ◽  
VANESSA SILVA ◽  
ADRIANA SILVA ◽  
NUNO SILVA ◽  
JESSICA RIBEIRO ◽  
...  

ABSTRACT The prevalence and diversity of Staphylococcus species from wild European rabbits (Oryctolagus cuniculus) in the Azores were investigated, and the antibiotic resistance phenotype and genotype of the isolates were determined. Nasal samples from 77 wild European rabbits from São Jorge and São Miguel islands in Azores were examined. Antibiotic susceptibility of the isolates was determined using the Kirby-Bauer disk diffusion method, and the presence of antimicrobial resistance genes and virulence factors was determined by PCR. The genetic lineages of S. aureus isolates were characterized by spa typing and multilocus sequence typing. A total of 49 staphylococci were obtained from 35 of the 77 wild rabbits. Both coagulase-positive (8.2%) and coagulase-negative (91.8%) staphylococci were detected: 4 S. aureus, 17 S. fleurettii, 13 S. sciuri, 7 S. xylosus, 4 S. epidermidis, and 1 each of S. simulans, S. saprophyticus, S. succinus, and S. equorum. The four S. aureus isolates showed methicillin susceptibility and were characterized as spa type t272/CC121, Panton-Valentine leukocidin negative, and hlB positive. Most of the coagulase-negative staphylococci showed resistance to fusidic acid and beta-lactams, and multidrug resistance was identified especially among S. epidermidis isolates. The mecA gene was detected in 20 isolates of the species S. fleurettii and S. epidermidis, associated with the blaZ gene in one S. epidermidis isolate. Five antimicrobial resistance genes were detected in one S. epidermidis isolate (mecA,dfrA,dfrG,aac6′-aph2′′, and ant4). Our results highlight that wild rabbits are reservoirs or “temporary hosts” of Staphylococcus species with zoonotic potential, some of them carrying relevant antimicrobial resistances. HIGHLIGHTS


1990 ◽  
Vol 5 (5) ◽  
pp. 895-902
Author(s):  
H. Issa

Retrospectively we evaluated the records of 68 children with brucellosis. We found 58.2% had consumed unpasteurized milk and dairy products. Nonspecific manifestations included: arthralgia [78%], fever [75%]and sweating [60%]. Localized manifestations included limping [75%]and arthritis [54%]. Leukopenia was found in 51% of children and anaemia in 24%. Brucella species was cultured for blood of 16 [23.5%]patients. Combination therapy containing streptomycin was more effective than gentamicin combinations


2020 ◽  
Vol 8 (9) ◽  
pp. 1317
Author(s):  
Laura Ruiz-Ripa ◽  
Paula Gómez ◽  
Carla Andrea Alonso ◽  
María Cruz Camacho ◽  
Yolanda Ramiro ◽  
...  

The objective of this study was to determine the prevalence and diversity of coagulase-negative staphylococci (CoNS) species from wild birds in Spain, as well as to analyze the antimicrobial resistance phenotype/genotype and the virulence gene content. During 2015–2016, tracheal samples of 242 wild birds were collected in different regions of Spain for staphylococci recovery. The species identification was performed using MALDI-TOF. The antimicrobial resistance phenotype and genotype was investigated by the disk diffusion method and by PCR, respectively. The presence of the virulence genes lukF/S-PV, tst, eta, etb, etd and scn was investigated by PCR. Moreover, CoNS carrying the mecA gene were subjected to SCCmec typing. Of the tested animals, 60% were CoNS-carriers, and 173 CoNS isolates were recovered from the 146 positive animals, which belonged to 11 species, with predominance of S. sciuri (n = 118) and S. lentus (n = 25). A total of 34% of CoNS isolates showed a multidrug resistance phenotype, and 42 mecA-positive methicillin-resistant CoNS (MRCoNS) were detected. The isolates showed resistance to the following antimicrobials (percentage of resistant isolates/antimicrobial resistance genes detected): penicillin (49/ blaZ, mecA), cefoxitin (24/ mecA), erythromycin and/or clindamycin (92/ erm(B), erm(C), erm(43), msr(A), mph(C), lnu(A), lsa(B), vga(A) and sal(A)), gentamicin and/or tobramycin (5/ aac(6′)-Ie-aph(2″)-Ia, ant(4′)-Ia), streptomycin (12/str), tetracycline (17/ tet(K), tet(L), tet(M)), ciprofloxacin (4), chloramphenicol (1/ fexA), fusidic acid (86/ fusB, fusD) and trimethoprim–sulfamethoxazole (1/ dfrK). None of the isolates harbored the lukF/S-PV, eta, etb, etd and scn genes, but two S. sciuri isolates (1%) carried the tst gene. Wild birds are frequently colonized by CoNS species, especially S. sciuri. We identified scavenging on intensively produced livestock and feeding on landfills as risk factors for CoNS carriage. High proportions of MRCoNS and multidrug resistant CoNS were detected, which coupled with the presence of important virulence genes is of concern.


2017 ◽  
Vol 62 (No. 9) ◽  
pp. 479-487 ◽  
Author(s):  
J. Siugzdaite ◽  
A. Gabinaitiene

The objective of this study was to evaluate the prevalence of coagulase-negative staphylococci in healthy dogs and to determine whether methicillin-resistant staphylococci expressed the mecA gene. Nasal and rectal swab samples were taken from 50 clinically healthy dogs. The prevalence of coagulase-negative staphylococci was evaluated according to phenotypic properties. The agar diffusion method was applied to evaluate antimicrobial resistance and the prevalence of methicillin resistance was determined using PCR analysing the mecA gene. A total of 59 coagulase-negative staphylococcus strains were isolated from the nostrils and rectums of 37 (74%) clinically healthy dogs. The prevalence of coagulase-negative staphylococci in female dogs was significantly higher compared with male dogs (P < 0.05). The results of antimicrobial susceptibility testing showed that 6.7% of the strains were resistant to oxacillin, 23.7% were resistant to penicillin, 22% to ampicillin and 16.9% to erythromycin. The mecA PCR revealed one oxacillin-sensitive and four oxacillin-resistant coagulase-negative staphylococci strains to be mecA carriers. Staphylococcus sciuri (60%) and Staphylococcus warneri (20%) were the most prevalent species among methicillin-resistant coagulase negative staphylococci. High antimicrobial resistance rates for these bacteria were observed against penicillin (100%), ampicillin (100%), oxacillin (80%), erythromycin (80%) and gentamicin (60%). All strains were susceptible to vancomycin and enrofloxacin. It is assumed that methicillin-resistance genes evolved in coagulase-negative staphylococcus and were then horizontally transferred among staphylococci.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Majoie Géroxie Tohoyessou ◽  
Wassiyath Mousse ◽  
Haziz Sina ◽  
Fernique Kona ◽  
Tania Azanghadji ◽  
...  

Staphylococcus species are considered as one of the major pathogens causing outbreaks of food poisoning. The aim of this work was to assess the toxinogenic and antibiotic susceptibility profiles of the strains of Staphylococcus spp isolated from three types of fermented dairy products (yoghourt, millet dêguê, and couscous dêguê). The isolation of the Staphylococcus strains was performed on selective media, and their identification was done using biochemical and molecular methods. The susceptibility at 15 antibiotics tested was assessed using the disc diffusion method. The immunodiffusion method was used to evaluate the toxin (luk-E/D, luk-S/F, ETA, and ETB) production. Biofilm formation was qualitatively researched on microplates. Less than half (42.77%) of the collected samples were contaminated with Staphylococcus spp. The yoghourt and millet dêguê samples collected in the afternoon were more contaminated than those collected in the morning. The S. aureus, S. capitis, and S. xylosus strains, respectively, were the most present. S. aureus was the only coagulase-positive species identified in our samples. The highest resistance to antibiotics was observed with penicillin (100%) irrespective of the nature of the sample. S. aureus strains were highly (71.4%) resistant to methicillin. The S. aureus strains were the most biofilm-forming (27.6%), followed by S. capitis strains. Panton and Valentine’s leukocidin (luk-S/F) was produced by only S. aureus strains at a rate of 8.33%. Only coagulase-negative Staphylococcus (CNS) produced Luk-E/D. The high rates of Staphylococci contamination indicate bad hygiene quality during the production and distribution of dairy products. It is, therefore, necessary to improve the quality of fermented milk products.


2017 ◽  
Vol 47 (7) ◽  
Author(s):  
Jamile de Oliveira Hachiya ◽  
Gabriel Augusto Marques Rossi ◽  
Laryssa Freitas Ribeiro ◽  
Rafael Akira Sato ◽  
Higor Oliveira Silva ◽  
...  

ABSTRACT: This study focused on counting Staphylococcus spp. in curd cheeses “requeijão” and “especialidade láctea type requeijão” sold in Brazil, assessing the presence of mecA gene in obtained isolates and establishing antimicrobial resistance profile of the mecA gene positive isolates. To this, a set of 200 samples of these dairy products were evaluated. Low counts of Staphylococcus spp. were observed in these dairy products. All the isolates were determined as coagulase-negative strains using coagulase test and PCR. However, two isolates (3.70%) were carriers of mecA gene and they can be considered as risk for public health. These isolates presented resistance to penicillin, oxacillin and erythromycin. In conclusion, low counts of Staphylococcus were detected in curd cheese “requeijão” and “especialidade láctea type requeijão” sold in Brazil. However, coagulase-negative methicillin-resistant Staphylococcus spp. was detected in these dairy products. This is the first report of the detection of methicillin-resistant Staphylococcus spp. in heat-treated dairy products in Brazil. Results served as a warning to public sanitary authorities to control multidrug-resistant strains in veterinary and human medicine.


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