Geni virulencije i antimikrobna osjetljivost izolata bakterije Escherichia coli dobijenih od krava s mastitisom u pokrajini Mashhad, Iran – kratko priopćenje

The purpose of this study was to determine the virulence genes and antimicrobial resistance patterns of Escherichia coli isolated from milk samples of cows with bovine mastitis. Forty-seven E. coli isolates from clinical mastitis milk samples, from five dairy farms in Northeast of Iran, were subjected to multiplex PCR to determine virulence genes stx1, stx2, eaeA, hlyA, sta, F4, F17, fliC, and rfbE. In addition, antimicrobial susceptibility was assessed by applying disk diffusion methods. The eaeA and stx1 genes were most frequently detected in 42 (89.3%) and 34 (72.3%) isolates, respectively. However, the least frequent gene was F41 as it was found in only one isolate (2.1%). Furthermore, 9 out of 47 isolates were hlyA positive, and four isolates harbored the sta gene. The antimicrobial susceptibility demonstrated the highest resistance against lincomycin (100%) and neomycin (91.4%). Since these bacteria represent a high-risk pathogen on farms, the emergence of multiple antibiotic-resistant and pathogenic E. coli strains should be of great concern for public health.Cilj je istraživanja bio odrediti gene virulencije i antimikrobnu rezistencije bakterije Escherichia coli izolirane iz uzoraka mlijeka krava s mastitisom. Ukupno 47 izolata bakterije E. coli iz uzoraka mlijeka krava s kliničkim mastitisom, s pet mliječnih farmi u sjeveroistočnom Iranu, podvrgnuto je protokolu multipleks PCR-a kako bi se odredili geni virulencije stx1, stx2, eaeA, hlyA, sta, F4, F17, fliC i rfbE. Antimikrobna je osjetljivost procijenjena primjenom disk-difuzijske metode. Najčešće određeni geni jesu gen eaeA, u 42 izolata (89,3 %) i gen stx1, u 34 izolata (72,3 %). Najrjeđi gen bio je F41, koji je pronađen u jednom izolatu (2,1 %). Nadalje, 9 od 47 izolata bilo je hlyA pozitivno, a četiri su izolata sadržavala gen sta. Procjena antimikrobne je osjetljivosti pokazala je najveću rezistenciju na linkomicin (100 %) i neomicin (91,4 %). Nalazi upućuju da se radi o visokorizičnim patogenima na farmama krava, stoga bi pojava višestruko rezistentnih i patogenih sojeva E. coli trebala izazvati veliku javnozdravstvenu zabrinutost

Fenotipsko i genotipsko istraživanje otpornosti na antimikrobne lijekove i proizvodnja beta-laktamaze proširenog spektra kod bakterije Escherichia coli izolirane iz krava s mastitisom

Escherichia coli has been one of the most highlighted pathogens isolated from clinical cases of mastitis. Unfortunately, the deficiency of appropriate antimicrobial stewardship and overuse of antimicrobial agents have increased antimicrobial resistance in animal isolates. The current study aimed to demonstrate the prevalence of extended-spectrum beta-lactamase (ESBL) production, resistance genes, and multi drug resistant (MDR) among E. coli isolates from cases of clinical mastitis. For this purpose, 40 E. coli isolates were collected from clinical mastitis milk samples from five farms in Mashhad, Iran. The antimicrobial susceptibility testing (AST) was applied to 15 antimicrobial agents of veterinary and human medicine interest. Also, ESBL production was evaluated using a doubledisc synergy test (DDST). The distribution of 20 resistance genes was sought among E. coli isolates by six multiplexPCR and three uniplex-PCR assays. The highest sensitivity was identified against imipenem and amikacin (100%). On the other hand, the highest resistance was observed for tetracycline and trimethoprim-sulfamethoxazole (70% - 72.5%), respectively. According to the AST and DDST tests, one isolate was confirmed as ESBL-producing and MDR. In addition, the most frequent resistance genes were blaTEM and AmpC (100% each). The qnrA encoding resistance to quinolones was similarly prevalent and detected in 50% of the isolates. In conclusion, at least three resistant genes were detected in 28 isolates (70%), but the majority of isolates were sensitive against most of the tested antibiotics. This fact might relate to the low expression of these genes within the isolates. The horizontal gene transfer of the present genes may confer resistance to other related bacterial species in humans or domestic animals.Escherichia coli jedan je od najistaknutijih patogena izoliranih kod kliničkih slučajeva mastitisa. Nažalost, izostanak odgovarajućeg upravljanja antimikrobnim lijekovima i njihova prekomjerna upotreba povećali su otpornost varijanti izoliranih iz životinja prema tim lijekovima. Cilj je ovog istraživanja bio prikazati prevalenciju proizvodnje beta-laktamaze proširenog spektra (ESBL), gensku rezistenciju i višestruku rezistentnciju na lijekove (MDR) među izolatima E. coli dobivenim od krava s kliničkim mastitisom. U tu je svrhu prikupljeno 40 izolata E. coli iz uzoraka mlijeka krava s pet farmi u Mashhadu u Iranu. Istraživanje osjetljivosti na antimikrobne lijekove (AST) otkrilo je 15 antimikrobnih tvari važnih za veterinarsku i humanu medicinu. Proizvodnja ESBL-a pritom je procijenjena upotrebom testa sinergije s dvostrukim diskom (engl. double-disc synergy test, DDST). Raspodjela 20 gena rezistancije među izolatima E. coli pretražena je putem šest multiplex-PCR testa i tri uniplex-PCR testa. Najveća je osjetljivost pronađena na imipenem i amikacin (100%), dok je najveća rezistencija uočena kod tetraciklina (70%) i trimetoprim-sulfametoksazola (72,5%). Prema testovima AST i DDST, jedan je izolat potvrđen kao proizvod ESBL-a i MDR. Najveća (100 %) je stopa gena rezistencije uočena za gene blaTEM i AmpC. Gen qnrA koji kodira rezistenciju na kinolone imao je također visoku prevalenciju i otkriven je u 50% izolata. Zaključeno je da su najmanje tri gena rezistencije otkrivena u 28 izolata (70%). Većina se izolata pokazala osjetljivima na antibiotike testirane ovim istraživanjem. Ta spoznaja može biti povezana s niskom ekspresijom gena rezistencije u izolatima. Horizontalni prijenos ovih gena može uzrokovati rezistenciju prema drugim srodnim bakterijskim vrstama u ljudi i kod domaćih životinja

Detection of efflux pump genes in multiresistant Acinetobacter baumannii ST2 in Iran

Acinetobacter baumannii, as a nosocomial pathogen has become a worldwide concern in recent years. In the current study, the resistance to tetracyclines and colistin were assessed in the isolates from different provinces of Iran. During the timeline of this study, a number of 270 isolates of A. baumannii were collected from tracheal aspirates, wounds, urine and blood cultures. The minimum inhibitory concentration (MIC) for tetracycline, doxycycline, minocycline, tigecycline and colistin were evaluated. Tetracycline resistance genes were assessed by PCR. The mean expression level of adeB, adeJ and adeG were assessed using semi quantitative Real-Time PCR. The clonal relationship of the isolates was evaluated by the repetitive extragenic palindromic PCR (REP-PCR), International Clonal (IC) Lineage Multiplex PCR and multilocus sequence typing (MLST) (Pasteur scheme) methods. The MIC by microdilution method showed that 87.5, 51.4, 28, 0.74 and 0% of the isolates were resistant to tetracycline, doxycycline, minocycline, tigecycline and colistin respectively. The prevalence of tetracycline resistance genes was 99.2, 99.2, 98, 86.7, 10, 3.33, 0.37, 0% for adeB, adeJ, adeG, tetB, tetA(39), tetA, tetM and tetH in tetracycline-resistant isolates. Moreover, the expression level of adeB, adeJ, adeG genes in tigecycline-nonsusceptible A. baumannii (TNAB) strain was higher compared to the tigecycline-susceptible A. baumannii (TSAB). A broad genomic diversity was revealed, but ST2 was the most prevalent ST. Our results indicated that tetracycline resistance in Iran is mediated by resistance-nodulation-cell division (RND) and tetB efflux pumps

The global prevalence of gastric cancer in Helicobacter pylori-infected individuals: a systematic review and meta-analysis

Abstract Background Helicobacter pylori is a gastrointestinal pathogen that infects around half of the world's population. H. pylori infection is the most severe known risk factor for gastric cancer (GC), which is the second highest cause of cancer-related deaths globally. We conducted a systematic review and meta-analysis to assess the global prevalence of GC in H. pylori-infected individuals. Methods We performed a systematic search of the PubMed, Web of Science, and Embase databases for studies of the prevalence of GC in H. pylori-infected individuals published from 1 January 2011 to 20 April 2021. Metaprop package were used to calculate the pooled prevalence with 95% confidence interval. Random-effects model was applied to estimate the pooled prevalence. We also quantified it with the I2 index. Based on the Higgins classification approach, I2 values above 0.7 were determined as high heterogeneity. Results Among 17,438 reports screened, we assessed 1053 full-text articles for eligibility; 149 were included in the final analysis, comprising data from 32 countries. The highest and lowest prevalence was observed in America (pooled prevalence: 18.06%; 95% CI: 16.48 − 19.63; I2: 98.84%) and Africa (pooled prevalence: 9.52%; 95% CI: 5.92 − 13.12; I2: 88.39%). Among individual countries, Japan had the highest pooled prevalence of GC in H. pylori positive patients (Prevalence: 90.90%:95% CI: 83.61–95.14), whereas Sweden had the lowest prevalence (Prevalence: 0.07%; 95% CI: 0.06–0.09). The highest and lowest prevalence was observed in prospective case series (pooled prevalence: 23.13%; 95% CI: 20.41 − 25.85; I2: 97.70%) and retrospective cohort (pooled prevalence: 1.17%; 95% CI: 0.55 − 1.78; I 2: 0.10%). Conclusions H. pylori infection in GC patients varied between regions in this systematic review and meta-analysis. We observed that large amounts of GCs in developed countries are associated with H. pylori. Using these data, regional initiatives can be taken to prevent and eradicate H. pylori worldwide, thus reducing its complications