Use of REP- and ERIC-PCR to reveal genetic heterogeneity of Vibrio cholerae from edible ice in Jakarta, Indonesia

Non-serogroup O1/O139 agglutinable Vibrio cholerae: a phylogenetically and genealogically neglected yet emerging potential pathogen of clinical relevance

Somatic antigen agglutinable type-1/139 Vibrio cholerae (SAAT-1/139-Vc) members or O1/O139 V. cholerae have been described by various investigators as pathogenic due to their increasing virulence potential and production of choleragen. Reported cholera outbreak cases around the world have been associated with these choleragenic V. cholerae with high case fatality affecting various human and animals. These virulent Vibrio members have shown genealogical and phylogenetic relationship with the avirulent somatic antigen non-agglutinable strains of 1/139 V. cholerae (SANAS-1/139- Vc) or O1/O139 non-agglutinating V. cholerae (O1/O139-NAG-Vc). Reports on implication of O1/O139-NAGVc members in most sporadic cholera/cholera-like cases of diarrhea, production of cholera toxin and transmission via consumption and/or contact with contaminated water/seafood are currently on the rise. Some reported sporadic cases of cholera outbreaks and observed change in nature has also been tracable to these non-agglutinable Vibrio members (O1/O139-NAGVc) yet there is a sustained paucity of research interest on the non-agglutinable V. cholerae members. The emergence of fulminating extraintestinal and systemic vibriosis is another aspect of SANAS-1/139- Vc implication which has received low attention in terms of research driven interest. This review addresses the need to appraise and continually expand research based studies on the somatic antigen non-serogroup agglutinable type-1/139 V.cholerae members which are currently prevalent in studies of water bodies, fruits/vegetables, foods and terrestrial environment. Our opinion is amassed from interest in integrated surveillance studies, management/control of cholera outbreaks as well as diarrhea and other disease-related cases both in the rural, suburban and urban metropolis.

Molecular prevalence of resistance determinants, virulence factors and capsular serotypes among colistin resistance carbapenemase producing Klebsiella pneumoniae: a multi-centric retrospective study

The emergence of colistin-carbapenem-resistant Klebsiella pneumoniae (CCR-Kp) in bloodstream infection results in high mortality, and virulence factor contributes further to the difficulty of treatment. A total of 158 carbapenem-resistant K. pneumoniae (CRKP) isolates causing bloodstream infection were collected from three Indian tertiary care hospitals during the 9-month study period, of which 27 isolates exhibited resistance to both colistin and carbapenem antibiotics. In this study, all the strains were characterized for antimicrobial resistance, virulence factors and capsular serotypes that facilitate the development of colistin and carbapenem-resistant K.pneumoniae (CCR-Kp) in bloodstream infection. Fourteen isolates displayed extremely drug resistance (XDR), susceptible only to tigecycline, and the remaining 13 isolates displayed multidrug resistance (MDR). The gene prevalence analysis for CCR-Kp isolates showed the predominance of bla KPC (81.48%) followed by bla NDM (62.96%), bla VIM (37.03%) and bla IMP (18.51%) genes. The distribution of virulence genes was found to be fimH (81.48%), wabG (59.25%), mrkD (55.56%), entB (48.15%), irp1 (33.33%), and rmpA (18.52%). The capsular serotypes K1, K2, K5 and K54 have been identified in 16 isolates. The absence of plasmid-mediated colistin resistance (mcr) genes implies the involvement of other mechanisms. The ERIC and (GTG)5 molecular typing methods detected 18 and 22 distinct clustering patterns among the CCR-Kp isolates, respectively. A strong correlation between ERIC and (GTG)5 genotyping method was established with antimicrobial resistance patterns and virulence determinants at P < 0.05, while no correlation was found with capsular serotyping. Similar virulence and resistance typing among the isolates suggest hospital-acquired infection in a health care setup. These outcomes will advance our awareness of CCR-Kp outbreaks associated with tertiary care hospitals and help forecast their occurrence in the near future.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-03056-4.

Genetic relatedness in extended-spectrum beta-lactamase-producing Escherichia coli from clinical isolates using enterobacterial repetitive intergenic consensus polymerase chain reaction

OBJECTIVES

The aim of this study is to determine the genetic relatedness of extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli using the enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) technique.

METHODS

Suspected Gram-negative bacteria with their identities from the clinical samples were confirmed using Microgen GN-A-ID Kit. The double-disc synergy test was used to confirm for ESBL-producing E. coli. The susceptibility of the organisms was tested against eleven antimicrobial agents. A singleplex PCR assay was carried out targeting TEM, SHV, CTX-M, and OXA. ERIC-PCR performed, and band patterns obtained were visually evaluated. A dendrogram of the ERIC-PCR fingerprint pattern was done with the aid of DendroUPGMA using the cluster method.

RESULTS

Of the 576 clinical samples collected, 23 isolates were confirmed E. coli, and all (100%) are ESBL producers. The highest antibiotic resistance rate was recorded in cefixime (95.6%), and the least was amikacin (17.4%). The predominant ESBL gene is blaTEM genes (95.6%). Gel analysis of ERIC-PCR revealed 1-6 bands. The profiles of the ERIC-PCR differentiated the 23 E. coli isolates into four ERIC cluster types.

CONCLUSION

More than 80% of the isolates are sensitive to amikacin, with greater than 95% harboring blaTEM genes. Overall, ERIC obtained from the clinical specimens indicated some evidence in the genetic relatedness of the ESBL genes among E. coli isolates.

Characterization of V. cholerae O1 biotype El Tor serotype Ogawa possessing the ctxB gene of the classical biotype isolated from well water associated with the cholera outbreak in Kerala, South India

We investigated 22 water samples (17 well water and five pipe water - both chlorinated) and six soil samples from the surroundings of wells of the households of suspected patients from Palakkad district, Kerala (India), from where a cholera outbreak was reported during June-July 2016. A total of 25 Vibrio cholerae isolates were collected from three well water samples during a recent cholera outbreak. Biochemical and serological studies revealed that all of the isolates belonged to serogroup O1, biotype El Tor, serotype Ogawa. PCR assays confirmed the occurrence of ctxB, ctxA, hlyA, tcpA El Tor,VPI, ace, zot, ompW, rfbO1 and toxR genes in all isolates. The presence of the ctxB gene of the classical biotype in all of the El Tor isolates suggests that it is a new variant of El Tor biotype. Antibiogram profile of all V. cholerae O1 isolates revealed resistance towards five classes of antibiotics island and indicates that they were multidrug resistant. ERIC-PCR and PFGE finger prints showed the clonal relationship among the V. cholerae O1 isolates. The results of this study revealed the emergence of a new variant of El Tor biotype in the water samples from Palakkad district, from where a cholera outbreak was reported.

Comparative Assessment of Different PCR-Based Typing Methods of Pseudomonas aeruginosa Isolates

Introduction

Pseudomonas aeruginosa is one of the important causes of nosocomial infections. Analyzing the diversity of these isolates is important to control the diseases caused by them. Studies of molecular epidemiology depend on the application of typing methods.

Purpose

This study aims to assess the performance of PCR- based typing techniques (RAPD, ribotyping, tDNA, and ERIC) in determining the genetic diversity of 44 P. aeruginosa urinary isolates.

Methods

Performance parameters were analyzed for each of the tested methods. The banding pattern was assessed by calculating polymorphism, genotypic gene diversity and the effective multiplex ratio. Moreover, strain diversity, typeability, and discriminatory power were used to measure the efficiency of typing methods. The congruence among typing methods was calculated by Rand’s and Wallace coefficients.

Results

P-640 among RAPD primers and Ribo-2 among ribotyping primers were more informative as they gave high strain diversity, the highest number of clusters, and highest discriminatory power (ISD=70.45%, 29 clusters at 70% cutoff, DI=0.97 and ISD=75%, 25 clusters at 70% cutoff DI=0.969, respectively). Comparison of typing methods showed that RAPD-PCR gave the highest mean percent polymorphism per assay (76.85%) followed by ERIC-PCR. ERIC-PCR outperformed in most marker parameters; highest mean number of alleles, number of monomorphic bands per assay unit, mean genotypic gene diversity, effective multiplex ratio, and assay efficiency index. Calculated congruence revealed that individual methods demonstrate moderate to poor predictive power. Interestingly, this power increased by combining data obtained from another method.

Conclusion

RAPD primer (P-640) had more discrimination power followed by ribo-2 and ERIC. The performance and predictive power of typing methods can be improved by combining data obtained from different methods as ERIC+OPA-02 and ERIC+P-640 combinations gave complete typeability and discrimination of isolates. ERIC, ERIC+OPA-02, and ERIC+P-640 combinations can provide finer discrimination and classification of P. aeruginosa strains than the other tested methods.

Difference of Phenotype and Genotype Between Human and Environmental: Isolated Vibrio cholerae in Surabaya, Indonesia

Cholera due to Vibrio cholerae has been spreading worldwide, although the reports focusing on Indonesian V. cholerae are few. In this study, in order to investigate how V. cholerae transmitted to human from environment. We extended an epidemiological report that had investigated the genotype of V. cholerae isolated from human pediatric samples and environmental samples. We examined 44 strains of V. cholerae isolated from pediatric diarrhea patients and the environment such as shrimps or oysters collected in three adjacent towns in Surabaya, Indonesia. Susceptibilities were examined for 11 antibiotics. Serotype O1 or O139 genes and pathogenic genes including cholera toxin were detected. Multi-locus sequence typing (MLST) and enterobacterial repetitive intergenic consensus (ERIC)-PCR were also performed to determine genetic diversity of those isolates. Serotype O1 was seen in 17 strains (38.6%) with all pathogenic genes among 44 isolates. Other isolates were non-O1/non-O139 V. cholerae. Regarding antibiotic susceptibilities, those isolates from environmental samples showed resistance to ampicillin (11.4%), streptomycin (9.1%) and nalidixic acid (2.3%) but those isolates from pediatric stools showed no resistance to those 3 kinds of antibiotics. MLST revealed sequence type (ST) 69 in 17 strains (38.6%), ST198 in 3 strains (6.8%) and non-types in 24 strains (54.5%). All the ST69 strains were classified to O1 type with more than 95% similarity by ERIC-PCR, including all 6 (13.6%) isolates from environmental samples with resistance to streptomycin. In conclusion, V. cholerae O1 ST69 strains has been clonally spreading in Surabaya, exhibiting pathogenic factors and antibiotic resistance to streptomycin, especially in the isolates from environment.

Investigation of six plasmid-mediated quinolone resistance genes among clinical isolates of pseudomonas: a genotypic study in Saudi Arabia

Background: Quinolones are among the most effective antibiotics against Pseudomonas spp. Several chromosomal and/or plasmid-mediated quinolone-resistance mechanisms have been found in Pseudomonas.  Plasmid-mediated quinolone-resistance (PMQR) is mediated by quinolone-resistance (QNR) proteins, modifying enzymes or efflux pumps. Only a few previous studies examined the prevalence of quinolone-resistance in the Kingdom of Saudi Arabia (KSA) and showed it is increasing. Mechanisms of quinolone-resistance among Pseudomonas spp. in the KSA; examined herein; have not been extensively studied. Methods: Ninety-two Pseudomonas isolates were collected and their resistance to seven different types of quinolones was determined by the microbroth dilution method. PMQR mechanisms were examined using a PCR screen to identify six PMQR genes including qnrA, qnrB, qnrD, qnrS, aac(6´)-Ib-cr, and qepA. Clonal relatedness of the quinolone-resistant isolates was determined by ERIC-PCR. Results: Of the isolates, 42.4% (39/92) were resistant to 1-7 of the tested quinolones. Gemifloxacin resistance was the lowest (28.3%) while resistance to the other six quinolones were ≥ 35%. The most common biotype among the 39 quinolone-resistant isolates was resistance to the seven tested quinolones (26/39; 66.7%). qnrD, qnrS, and aac(6´)-Ib-cr were found in 31 (79.5%), 31 (79.5%) and 28 (71.8%) of the 39 isolates, respectively, and all three genes together were found in 22 of the 39 isolates (56.4%). qnrA, qnrB, and qepA were not detected in any of the isolates and two isolates did not harbor any of the six tested genes. The isolates showed 38 different ERIC profiles and only two isolates (Pa16 and Pa17) had an identical profile. Conclusion: This is the first description of PMQR mechanisms among clinical Pseudomonas isolates from the KSA, which appears to be mainly mediated by qnrD, qnrS, and aac(6´)-Ib-cr.

Evaluation of BOX-PCR and ERIC-PCR as Molecular Typing Tools for Pathogenic Leptospira

In the last decades, leptospirosis had gained public health concern due to morbidity and mortality rates caused by pathogenic Leptospira. The need for rapid and robust molecular typing methods to differentiate this zoonotic pathogen is of utmost importance. Various studies had been conducted to determine the genetic relatedness of Leptospira isolates using molecular typing methods. In this study, 29 pathogenic Leptospira isolates from rat, soil, and water samples in Sarawak, Malaysia, were characterized using BOX-PCR and ERIC-PCR. The effectiveness of these two methods with regard to the ease of interpretation, reproducibility, typeability, and discriminatory power was also being evaluated. Using BOX-PCR, six clusters and 3 single isolates were defined at a genetic distance percentage of 11.2%. ERIC-PCR clustered the isolates into 6 clusters and 2 single isolates at a genetic distance percentage of 6.8%. Both BOX-PCR and ERIC-PCR produced comparable results though the discriminatory index for ERIC-PCR (0.826) was higher than that for BOX-PCR (0.809). From the constructed dendrogram, it could be summarized that the isolates in this study were highly heterogeneous and genetically diverse. The findings from this study indicated that there is no genetic relatedness among the pathogenic Leptospira isolates in relation to the locality, source, and identity, with some exceptions. Out of the 29 pathogenic Leptospira isolates studied, BOX-PCR and ERIC-PCR successfully discriminated 4 isolates (2 isolates each) into the same cluster in relation to sample sources, as well as 2 isolates into the same cluster in association with the sample locality. Future studies shall incorporate the use of other molecular typing methods to make a more thorough comparison on the genetic relatedness of pathogenic Leptospira.

Genetic diversity of toxigenic Vibrio cholerae O1 from Sabah, Malaysia 2015

BACKGROUND

Cholera is an important health problem in Sabah, a Malaysian state in northern Borneo; however, Vibrio cholerae in Sabah have never been characterized. Since 2002, serogroup O1 strains having the traits of both classical and El Tor biotype, designated as atypical El Tor biotype, have been increasingly reported as the cause of cholera worldwide. These variants are believed to produce clinically more severe disease like classical strains.

PURPOSE

The purpose of this study is to investigate the genetic diversity of V.cholerae in Sabah and whether V.cholerae in Sabah belong to atypical El Tor biotype.

METHODS

ERIC-PCR, a DNA fingerprinting method for bacterial pathogens based on the enterobacterial repetitive intergenic consensus sequence, was used to study the genetic diversity of 65 clinical V.cholerae O1 isolates from 3 districts (Kudat, Beluran, Sandakan) in Sabah and one environmental isolate from coastal sea water in Kudat district. In addition, we studied the biotype-specific genetic traits in these isolates to establish their biotype.

RESULTS

Different fingerprint patterns were seen in isolates from these three districts but one of the patterns was seen in more than one district. Clinical isolates and environmental isolate have different patterns. In addition, Sabah isolates harbor genetic traits specific to both classical biotype (ctxB-1, rstR^Cla) and El Tor biotype (rstR^ET, rstC, tcpA^ET, rtxC, VC2346).

CONCLUSION

This study revealed that V.cholerae in Sabah were genetically diverse and were atypical El Tor strains. Fingerprint patterns of these isolates will be useful in tracing the origin of this pathogen in the future.

Enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis as a reliable evidence for suspected Shigella spp. outbreaks

BACKGROUND

Shigellosis remains a serious public health problem and an important cause of morbidity and mortality worldwide. The aim of this study was to characterize fliC and the genetic relatedness of Shigella spp. isolated during a one-year period from children in a suspected outbreak in Tehran, Iran.

METHODS AND RESULTS

Fifty Shigella spp. were isolated from 3779 stool samples of children with diarrhea (prevalence rate: 1.32%). Among the isolates, 92% were characterized as Shigella sonnei, while 6% and 2% were identified as S. flexneri and S. boydii, respectively. S. dysenteriae was not recovered from the patients. All isolates were negative for fliC except for Shigella standard strains. The enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) profiles allowed differentiating the 50 isolates into 5 ERIC types, which were grouped into five clusters (ET1-ET5). Computer-assisted clustering of the strains showed a high degree of similarity among the isolates.

CONCLUSION

In conclusion, given the clonal correlation of the Shigella strains isolated in this study and the lack of fliC among them, we propose that probably a single or limited fliC-defected Shigella clone spread and caused the outbreak.

Salmonella Contamination in Layer Farms in China: Detection and Genetic Analysis

Salmonella is the most common cause of foodborne illnesses worldwide. Poultry eggs are a major contamination source of Salmonella. The prevalence of Salmonella has been effectively reduced since a series of measures were taken to reduce contamination in egg-laying houses. In the present study, 1,512 environmental samples obtained from layer farms of different production scales were screened in a voluntary Salmonella survey study. Contaminations were detected using a PCR method. Genetic relationships among Salmonella samples were specified using molecular typing by enterobacterial repetitive intergenic consensus (ERIC)-PCR. The survey results showed that two layer farms, located in the Shandong and Hebei provinces, were contaminated with Salmonella. Thirty-one samples from these two farms, including feed, drinking nipples, egg collection belt, air inlets and outlets, air, overshoes, and eggshells, were identified as Salmonella-positive. It was observed that certain samples within the henhouses as well as in the egg collecting areas showed relatively high genetic similarities. The survey conclusively revealed minor Salmonella contamination in northern China. Moreover, various areas within the layer farms were identified as part of the propagation chain of Salmonella. Furthermore, evidence of cross-contamination of Salmonella was found in the laying houses and egg collection areas, even between these two regions. Therefore, it is necessary to establish routine Salmonella detection and subsequent environmental control measures in order to decrease the prevalence of Salmonella.

Molecular Epidemiology Survey of Staphylococcus aureus Panton-Valentine Leukocidin-positive Isolated from Sanandaj, Iran

Background:

Staphylococcus aureus strains that are Panton–Valentine leukocidin (PVL) positive cause severe skin and soft tissue infections as well as necrotizing pneumonia. The presence of PVL gene is a marker for methicillin-resistant S. aureus; therefore, survey on prevalence and phylogenetic distribution of PVL is of great importance for public health. The aim of this research was molecular epidemiology survey of S. aureus PVL positive, isolated from two tertiary hospitals of Sanandaj.

Materials and Methods:

A total of 264 staphylococci isolates were collected from clinical specimens, hospital personnel and hospital environment of two tertiary hospitals of Sanandaj, in 2012 (Toohid and Besat). Bacterial cultures and biochemical tests were performed for S. aureus detection. Then, polymerase chain reaction (PCR) and repetitive sequence-based PCR (rep-PCR) were used for the determination of prevalence and molecular epidemiology of S. aureus PVL, respectively. Data were analyzed using the Fisher's exact test (P < 0.05).

Results:

From 264 staphylococci isolates, 88 (33.33%) were detected as S. aureus. Furthermore, 20 out of 88 (22.72%) strains of S. aureus were PVL positive according to PCR results. Rep-PCR showed six main clusters of S. aureus samples. PVL had similar clonality between different samples. No significant relationship was observed between PVL positive S. aureus and rep-PCR patterns (P = 0.98).

Conclusion:

These results showed that a clone of S. aureus PVL positive has spread between the community and hospital settings. Therefore, appropriate measures are required to prevent the spread of staphylococci and other bacteria in hospitals.

Molecular and Genomic Characterization of Vibrio mimicus Isolated from a Frozen Shrimp Processing Facility in Mexico

Vibrio mimicus is a gram-negative bacterium responsible for diseases in humans. Three strains of V. mimicus identified as V. mimicus 87, V. mimicus 92 and V. mimicus 93 were isolated from a shrimp processing facility in Guaymas, Sonora, Mexico. The strains were analyzed using several molecular techniques and according to the cluster analysis they were different, their similarities ranged between 51.3% and 71.6%. ERIC-PCR and RAPD (vmh390R) were the most discriminatory molecular techniques for the differentiation of these strains. The complete genomes of two strains (V. mimicus 87, renamed as CAIM 1882, and V. mimicus 92, renamed as CAIM 1883) were sequenced. The sizes of the genomes were 3.9 Mb in both strains, with 2.8 Mb in ChI and 1.1 Mb in ChII. A 12.7% difference was found in the proteome content (BLAST matrix). Several virulence genes were detected (e.g. capsular polysaccharide, an accessory colonization factor and genes involved in quorum-sensing) which were classified in 16 categories. Variations in the gene content between these genomes were observed, mainly in proteins and virulence genes (e.g., hemagglutinin, mobile elements and membrane proteins). According to these results, both strains were different, even when they came from the same source, giving an insight of the diversity of V. mimicus. The identification of various virulence genes, including a not previously reported V. mimicus gene (acfD) in ChI in all sequenced strains, supports the pathogenic potential of this species. Further analysis will help to fully understand their potential virulence, environmental impact and evolution.

Molecular Characterization of Vibrio cholerae Isolated From Clinical Samples in Kurdistan Province, Iran

Background:

Vibrio cholerae causes diarrhoeal disease that afflicts thousands of people annually. V. cholerae is classified on the basis of somatic antigens into serovars or serogroups and there are at least 200 known serogroup. Two serogroups, O1 and O139 have been associated with epidemic diseases. Virulence genes of these bacteria are OmpW, ctxA and tcpA.

Objectives:

Due to the importance of V. cholerae infection and developing molecular diagnostics of this organism in medical and microbiology sciences, this study aimed to describe molecular characterization of V. cholerae isolated from clinical samples using a molecular method.

Materials and Methods:

In this study, 48 samples were provided during summer 2013 (late August and early September) by reference laboratory. Samples were assessed using biochemical tests initially. The primer of OmpW, ctxA and tcpA genes was used in Polymerase Chain Reaction (PCR) protocols. Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR and Repetitive Extragenic Palindromic (REP)-PCR methods were used to subtype V. cholerae.

Results:

In this study, from a total of 48 clinical stool samples 39 (81.2 %) were positive for V. cholerae in biochemical tests and bacteria culture tests. The PCR results showed that of 39 positive isolates 35 (89.7%), 34 (87.1%) and 37 (94.8%) were positive for ctxA, tcpA and OmpW gene, respectively. Also, in the REP-PCR method with ERIC primer strains were divided into 10 groups. In the REP-PCR method with REP primer, strains were divided into 13 groups.

Conclusions:

Polymerase chain reaction has specificity and accuracy for identification of the organism and is able to differentiate biotypes. Enterobacterial repetitive intergenic consensus sequence is one of the informative and discriminative methods for the analysis of V. cholerae diversity. The REP-PCR is a less informative and discriminative method compared to other methods for the analysis of V. cholerae diversity.

Study of aminoglycoside resistance genes in enterococcus and salmonella strains isolated from ilam and milad hospitals, iran

Background:

Aminoglycosides are a group of antibiotics that have been widely used in the treatment of life-threatening infections of Gram-negative bacteria.

Objectives:

This study aimed to evaluate the frequency of aminoglycoside resistance genes in Enterococcus and Salmonella strains isolated from clinical samples by PCR.

Materials and Methods:

In this study, 140 and 79 isolates of Enterococcus and Salmonella were collected, respectively. After phenotypic biochemical confirmation, 117 and 77 isolates were identified as Enterococcus and Salmonella, respectively. After the biochemical identification of the isolates, antibiotic susceptibility for screening of resistance was done using the Kirby-Bauer method for gentamicin, amikacin, kanamycin, tobramycin and netilmycin. DNA was extracted from resistant strains and the presence of acc (3)-Ia, aac (3′)-Ib, acc (6)-IIa ,16SrRNA methylase genes (armA and rat) was detected by PCR amplification using special primers and positive controls.

Results:

Enterococcus isolates have the highest prevalence of resistance to both kanamycin and amikacin (68.4%), and Salmonella isolates have the highest prevalence of resistance against kanamycin (6.9%). Ninety-three and 26 isolates of Enterococcus and Salmonella at least were resistant against one of the aminoglycosides, respectively. Moreover, 72.04%, 66.7%, and 36.6% of the resistant strains of Enterococcus had the aac (3′)-Ia, aac (3′)-IIa, and acc (6′)-Ib genes, respectively. None of the Salmonella isolates have the studied aminoglycoside genes.

Conclusions:

Our results indicate that acetylation genes have an important role in aminoglycoside resistance of the Enterococcus isolates from clinical samples. Moreover, Salmonella strains indicate very low level of aminoglycoside resistance, and aminoglycoside resistance genes were not found in Salmonella isolates. These results indicate that other resistance mechanisms, including efflux pumps have an important role in aminoglycoside resistance of Salmonella.