scholarly journals Prevalence and antimicrobial susceptibility of Listeria spp. isolated from bulk raw milk in north-eastern Poland

2022 ◽  
Vol 78 (03) ◽  
pp. 6628-2022
Author(s):  
MARTA SOŁTYSIUK ◽  
AGNIESZKA WISZNIEWSKA-ŁASZCZYCH ◽  
JOANNA WOJTACKA ◽  
BEATA WYSOK

Purpose of research: The aim of the study was to determine the presence of Listeria spp. strains in the milk samples obtained from dairy farms in north-eastern Poland and to determine the profile of resistance to antibiotics recommended in the treatment of listeriosis. Material and methods: 500 samples of bulk milk were analyzed. Milk samples were obtained from dairy farms located in Warmia and Mazury region in Poland. Chronic mastitis, requiring frequent and long-term use of antibiotics has been documented in these herds. Isolation of Listeria spp. was performed according to the standard procedure PN-EN ISO 11290-1: 2017-07. Antibiotic resistance testing was performed by the disc diffusion method according to the Clinical & Laboratory Standards Institute (CLSI) recommendations. Results: In total, out of 500 samples of pooled milk, based on biochemical properties, 8 isolates were confirmed as belonging to the genus Listeria (1.6%). The further identification of Listeria strains on the basis of MicrobactListeria12L showed that 3 strains (3/8, 37.5%) belonged to L. monocytogenes species and 5 strains (5/8, 62.5%) belonged to L. innocua species. The analysis of sensitivity to commonly used antimicrobial agents showed that all isolates, both belonging to L. monocytogenes and L. innocua species, were sensitive to ampicillin. Multidrug resistance, defined as resistance to at least three classes of antibiotics, was confirmed among four isolates (50%). Research summary: The studies undertaken revealed that raw milk can pose a risk for public health due to the prevalence of pathogenic Listeria spp. among which multidrug resistant strains are present. It is therefore necessary to rationalize the use of antibiotics and to monitor bacterial resistance in the food production environment.

2007 ◽  
Vol 59 (2) ◽  
pp. 508-512 ◽  
Author(s):  
B.R. Paneto ◽  
R.P. Schocken-Iturrino ◽  
C. Macedo ◽  
E. Santo ◽  
J.M. Marin

The occurrence of toxigenic Escherichia coli in raw milk cheese was surveyed in Middle Western Brazil. Fifty samples of cheese from different supermarkets were analyzed for E.coli. The isolates were serotyped and screened for the presence of verotoxigenic E. coli (VTEC) and enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR). The susceptibility to thirteen antimicrobial agents was evaluated by the disk diffusion method. E.coli were recovered from 48 (96.0%) of the samples. The serogroups identified were O125 (6.0%), O111 (4.0%), O55 (2.0%) and O119 (2.0%). Three (6.0%) and 1(2.0%) of the E.coli isolates were VTEC and ETEC, respectively. Most frequent resistance was observed to the following antimicrobials: cephalothin (60.0%), nalidixic acid (40.0%), doxycyclin (33.0%), tetracycline (31.0%) and ampicillin (29.0%).


Author(s):  
Fateme DAVARZANI ◽  
Navid SAIDI ◽  
Saeed BESHARATI ◽  
Horieh SADERI ◽  
Iraj RASOOLI ◽  
...  

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.


2019 ◽  
Vol 40 (1) ◽  
pp. 163 ◽  
Author(s):  
Leandro Parussolo ◽  
Ricardo Antônio Pilegi Sfaciotte ◽  
Karine Andrezza Dalmina ◽  
Fernanda Danielle Melo ◽  
Ubirajara Maciel Costa ◽  
...  

The serrano artisanal cheese is a typical product from South region of Brazil, which is produced by skilled cheesemakers using raw milk. The contamination of this food by Escherichia coli has a great impact on public health, since it could threat the consumers’ health. The study evaluated the presence of virulence genes, antimicrobial susceptibility profiles and bofilm-production ability of Escherichia coli isolates obtained from raw milk and artisanal cheese produced in Southern Brazil. A total of 117 isolates of E. coli were characterized by multiplex PCR to detect the following virulence genes: eae for enteropatogenic E. coli (EPEC), lt and st for enterotoxigenic E. coli (ETEC), stx for shiga toxin-producing E. coli (STEC), stx and eae for enterohemorrhagic E. coli (EHEC), ipaH for enteroinvasive E. coli (EIEC) and aggR for enteroaggregative E. coli (EAEC). In addition, antimicrobial susceptibility profile to 22 antimicrobial agents was also performed by disk diffusion method, and we searched for extended-spectrum beta-lactamases (ESBL) and/or carbapenemase- producing isolates. Isolates that were positive for ESBL and carbapenemase were further investigated for the presence of the genes: blaTEM, blaSHV, blaOXA, blaCTX-M, for ESBL and blaOXA-48 for carbapenemase. Further, isolates had their ability to form biofilms investigated by the red Congo agar method. Virulence genes of E. coli were identified in 21.37% of the tested isolates, which were classified as EPEC (the most prevalent pathotype) and ETEC or EAEC. Ten (8.55%) of the total studied E. coli isolates revealed a multidrug-resistant profile, since they were resistant to three or more antimicrobial classes; whereas four isolates (3.42%) were classified as ESBL-producers and showed the presence of blaTEM gene. None of the isolates exhibited carbapenemase activity nor did they carry carbapenemase genes. From the total of E. coli isolates, 79 (67.52%) were considered potential biofilm producers. These results address a serious public health issue, since artisanal cheeses pose a risk to consumers’ health, since may be sources of dissemination of diarrheogenic E. coli, that can cause from subclinical to severe and fatal infections in children and adults, and also emphasize the need to improve adaptations/adjustments in the manufacturing processes of these products.


1988 ◽  
Vol 51 (11) ◽  
pp. 840-841 ◽  
Author(s):  
MICHAEL B. LIEWEN ◽  
MARK W. PLAUTZ

Raw milk samples were obtained from bulk storage tanks of individual dairy farms in eastern Nebraska during February and July of 1986. One hundred different farms were tested during each period. One-tenth ml of each sample was plated directly onto McBride's Listeria Agar (MLA) and 30 ml was subjected to a four-week cold enrichment procedure. Suspect colonies from MLA were subjected to biochemical tests to confirm identity. Nine percent of all raw milk samples examined were determined to be positive for Listeria species after the cold enrichment procedure. Four percent contained L. monocytogenes and five percent contained L. innocua. Six percent and two percent of samples were found to contain L. monocytogenes in February and July respectively.


2014 ◽  
Vol 83 (10) ◽  
pp. S9-S13 ◽  
Author(s):  
Lenka Vorlová ◽  
Lucia Hodulová ◽  
Ivana Borkovcová ◽  
Hana Přidalová ◽  
Romana Kostrhounová ◽  
...  

The aim of this study was to compare the iodine content in raw milk from organic and conventional dairy farms of different sizes. Milk samples were collected between 2012 and 2013, and the iodine content was determined by a Sandell-Kolthoff reaction after dry alkaline digestion of the milk samples. Comparing the iodine content in raw milk samples from small sized dairy farms (116.76 ± 46.29 μg/l) and large sized dairy farms (173.70 ± 35.42 μg/l), a significant difference in iodine content was observed (P ≤ 0.05). The lowest values were found in small and medium dairy farms, 45.30 μg/l and 40.46 μg/l, respectively. High variability (112.92 ± 94.74 μg/l) in the iodine content was detected in raw milk from medium sized dairy farms. When considering milk samples from organic dairy farms (119.29 μg /l ± 40.37) vs. conventional dairy farms (136.55 μg/l ± 42.91), no significant difference was detected. These results indicate higher iodine content in milk from large dairy farms regardless of conventional or organic farming methods.


Author(s):  
R.H. Mdegela ◽  
R. Ryoba ◽  
E.D. Karimuribo ◽  
E.J. Phiri ◽  
T. Loken ◽  
...  

A cross sectional study was conducted during October and November 2006 on 69 smallholder dairy farms with lactating cows in Mvomero and Njombe districts Tanzania, to determine the prevalence of mastitis and to assess the milk quality on the study farms. Clinical mastitis was investigated using clinical changes of udder and milk at animal level. Cow-side California Mastitis Test (CMT) and microbiological cultures were used to assess subclinical mastitis at quarter level. Milk quality was determined on bulk milk samples at herd level using alcohol and acidity tests, butter fat content, total solids, ash content as well as Delvotest® for antimicrobial residues. Overall prevalence of clinical mastitis at herd level in both districts was 21.7 % (n = 69). Based on CMT, prevalence of subclinical mastitis at animal level was 51.6 % (n = 91). Prevalence of bacterial isolates at animal level was 35.2 % (n = 91) while for fungal it was 16.7 % (n = 90). Based on CMT results, prevalence of subclinical mastitis at quarter level was 30 % (n = 353), while for bacteria and fungi it was 16 % and 6 % respectively. Contamination of milk with antimicrobial residues was 4.5 % (n =67). The milk quality parameters for most of the milk samples were within acceptable levels. Findings in this study have demonstrated high prevalence of subclinical mastitis that may contribute to low productivity of dairy cattle in both districts. About 20 % of CMT subclinical cases had no involvement of microbial pathogens that suggested the need for minimal interventions with antimicrobial agents. These findings call for use of udder disinfectants and improved milking hygiene as intervention strategies to control mastitis on the smallholder dairy farms in Tanzania.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Mude Shecho ◽  
Naod Thomas ◽  
Jelalu Kemal ◽  
Yimer Muktar

A cross-sectional study was carried out to determine antimicrobial drug resistance patterns of E. coli O157:H7 isolates and estimate the level of the pathogen. A total of 194 cloacae swab samples were collected randomly in two poultry farms. Standard cultural, biochemical, and serological (latex agglutination) methods were used to isolate E. coli O157:H7. The isolates were subjected to antimicrobial susceptibility testing using disc diffusion method. Out of 194 cloacae samples examined, 13.4% (n=26) were found to be positive for E. coli O157:H7. The finding indicated differences in E. coli O157:H7 infection among the different risk factors. Chicken from Adele Poultry Farm showed higher E. coli O157:H7 infection (OR = 3.89) than Haramaya University poultry farm and young birds had more infection (OR = 4.62) than adult birds. Of the total 14 antimicrobials included in the panel of study, the susceptibility results were varied with 96.15% and 0% E. coli O157:H7 isolates expressing resistance to erythromycin, clindamycin, spectinomycin, and ciprofloxacin, respectively. Multidrug resistance to more than two antimicrobial agents was detected in 24 (92.30%) of the isolates. The study showed high presence of antimicrobial resistant isolates of E. coli O157:H7. Further study is required to better understand the ecology and evolution of bacterial resistance to antimicrobial agents.


2020 ◽  
Vol 44 (4) ◽  
pp. 91-100
Author(s):  
F. O. Olufemi ◽  
O. A. Odunfa ◽  
P. A. Akinduti ◽  
O. B. Kehinde

 Milk contaminated with antibiotic resistant bacteria can be a major threat to public health. This study wasconducted toinvestigate the antibiotic susceptibility of bacterial isolates from goat's milk in Abeokuta. Nine (9) bacteria species comprising 182 isolates were identified in 73 milk samples collected from six (6) different places located some 2 - 50 kilometers apart in Abeokuta. Isolation and identification of the bacteria species were carried out using standard microbiological procedures. The bacteria species were Pseudomonas spp (22.28%), Micrococcus spp (21.74%), Staphylococcus aureus (19.02%), Staphylococcus saprophyticus (15.22%), Enterobacter spp (8.70%), Bacillus spp (5.43%), Pasteurella spp (4.89%), Escherichia coli (2.17%), and Citrobacter spp (0.54%). Antibiotic susceptibility of the isolates and minimum inhibitory concentration were determined using a panel of 10 antibiotics by disc diffusion method and standard guidelines. The bacterial load from milk samples obtained in various locations are as follows:-DUFARMS,0.1-1.2x10 cfu/mL;Eweje, 0.6-1.2x10 cfu/mL; Odeda, 0.6-3.5x10 cfu/mL; Elite, 1.0-5.5x10 cfu/mL; Elega, 0.1- 2.52x10 cfu/mL; and Obantoko 0.16-1.04x10 cfu/mL. The mean counts were 0.54 ± 0.40x10 cfu/mL; 0.78 ±0.13x10 cfu/mL; 1.83±1.23x10 cfu/mL; 2.58 ±1.45x10 cfu/mL; 8.51 ±5.60x10 cfu/mL and 4.14 ±3.90 x10 cfu/mL respectively. Antibiotic susceptibility results showed that the organisms were 100% resistant to Amoxicillin,86.26% to Ceftriazone, 84.62% to Streptomycin, 82.42% to Chloramphenicol and 78.02% to Cotrimoxazol. However, the isolates were only 6.04% resistant to Ofloxacin and 11.54% to Pefloxacin suggesting that these might just be the only two antibiotics that the pathogens might respond to. In conclusion, microbes that are ordinarily commensals may be highly resistant to commonly used Antibiotics. This could pose serious problems in managing outbreaks associated these microbes. Reservoirs for bacterial resistance may be present in healthy animal populations and research is needed to accurately quantify the problem, propose and evaluate practicable solutions. There is the need to clarify the role of environmental factors, agents, and transmission of bacterial resistance in apparently healthy livestock.  


2022 ◽  
Vol 82 ◽  
Author(s):  
Q. A. Naseer ◽  
X. Xue ◽  
X. Wang ◽  
S. Dang ◽  
S. U. Din ◽  
...  

Abstract Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in “De Man, Rogasa, and Sharp” broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell- free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.


2019 ◽  
Vol 20 ◽  
Author(s):  
Laryssa F. Ribeiro ◽  
Mayhara M. C. Barbosa ◽  
Fernanda R. Pinto ◽  
Leticia F. Lavezzo ◽  
Gabriel A. M. Rossi ◽  
...  

Abstract This study focused on detecting diarrheagenic Escherichia coli, enteropathogenic E. coli (EPEC), Shiga-toxin-producing E. coli (STEC), enterohemorrhagic E. coli (EHEC or STEC:EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC) in raw milk, water, and cattle feces sampled from non-technified dairy farms located in the northeastern São Paulo State, Brazil. Thirty-six water samples were collected at different points, namely, water wells (8 samples), water intended for human consumption (8 samples), water from milking parlor (8 samples), and water intended for animal consumption (7 samples), headwaters (1 sample), rivers (3 samples), and reservoirs (1 sample). Three raw milk samples were taken directly from bulk tanks in each farm, totalizing 24 samples. Feces samples were collected using rectal swabs from 160 bovines (20 animals per farm). E. coli was detected in 128 feces samples (80%), 16 raw milk samples (66.67%), and 20 water samples (55.56%). STEC (26 samples, 16.25%), EPEC (10 samples, 6.25%), STEC: EPEC (5 samples, 3.13%), and STEC: ETEC (1 sample, 0.63%) were the most prevalent strains detected in samples from cattle feces. EPEC, STEC, and STEC: EPEC strains were detected in 4.17% (1 sample), 16.67% (4 samples), and 4.17% (1 sample) of raw milk samples, respectively. STEC strains were detected in water used in the milking parlor, while no EAEC strain was detected. As a conclusion, cattle feces are important contamination sources of pathogenic E. coli in non-technified dairy farms and, consequently, cross-contamination among feces, water, and/or raw milk can occur. The use of quality water and hygienic practices during milking are recommended to avoid contamination since pathogens can be transmitted to humans via raw milk or raw milk cheese ingestion.


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