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1.
Rev Soc Bras Med Trop ; 53: e20200064, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32401864

RESUMEN

INTRODUCTION: Carbapenem-resistant Klebsiella pneumoniae infection lacks treatment options and is associated with prolonged hospital stays and high mortality rates. The production of carbapenemases is one of the most important factors responsible for this multi-resistance phenomenon. METHODS: In the present study, we analyzed the presence of genes encoding carbapenemases in K. pneumoniae isolates circulating in one of the public hospitals in the city of Aracaju, Sergipe, Brazil. We also determined the best combination of drugs that display in vitro antimicrobial synergy. First, 147 carbapenem-resistant K. pneumoniae isolates were validated for the presence of blaKPC, bla GES, bla NDM, bla SPM, bla IMP, bla VIM, and bla OXA-48 genes using multiplex polymerase chain reaction. Thereafter, using two isolates (97 and 102), the role of double and triple combinational drug therapy as a treatment option was analyzed. RESULTS: Seventy-four (50.3%) isolates were positive for bla NDM, eight (5.4%) for bla KPC, and one (1.2%) for both bla NDM and bla KPC. In the synergy tests, double combinations were better than triple combinations. Polymyxin B and amikacin for isolate 97 and polymyxin B coupled with meropenem for isolate 102 showed the best response. CONCLUSIONS: Clinicians in normal practice use multiple drugs to treat infections caused by multi-resistant microorganism; however, in most cases, the benefit of the combinations is unknown. In vitro synergistic tests, such as those described herein, are important as they might help select an appropriate multi-drug antibiotic therapy and a correct dosage, ultimately reducing toxicities and the development of antibiotic resistance.


Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/genética , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , beta-Lactamasas/genética , Brasil , ADN Bacteriano , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , Prevalencia
2.
Mem Inst Oswaldo Cruz ; 115: e200055, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32401997

RESUMEN

BACKGROUND Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis, and the number of new cases of multidrug resistant TB (MDR-TB), pre extensively drug-resistant TB (pre-XDR-TB) and extensively drug-resistant TB (XDR-TB) has increased considerably worldwide. OBJECTIVES Herein, using 156 M. tuberculosis isolates from 106 patients previously classified as MDR or pre-XDR or XDR isolates, we investigated the genetic mutation profiles associated with phenotypic resistances in patients with MDR-TB, pre-XDR-TB and XDR-TB, treatment outcomes and resistance evolution. METHODS Molecular analyses were performed by partial sequencing of the rpoB, katG, gyrA, gyrB, rrs genes and analysis of the fabG-inhA promoter region. Clinical, epidemiologic and demographic data were obtained from the TB Notification database system of São Paulo (TB-WEB) and the Information System for Special Tuberculosis Treatments (SITE-TB). FINDINGS Drug resistance was attributed to previously known mutations and a novel Asp449Val mutation in gyrB was observed in four isolates from the same patient. Ten patients had more than one isolate evaluated and eight of these patients displayed resistance progression. MAIN CONCLUSIONS The present study is the first to report the frequency of mutations related to second-line drug resistance in MDR-TB, pre-XDR-TB and XDR-TB isolates. The results could lead to the improvement of available technologies for the rapid detection of drug resistant TB.


Asunto(s)
Antituberculosos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Mutación/genética , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Adolescente , Adulto , Brasil , Tuberculosis Extensivamente Resistente a Drogas/microbiología , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Mycobacterium tuberculosis/aislamiento & purificación , Factores Socioeconómicos , Adulto Joven
3.
Mol Genet Genomics ; 295(4): 1001-1012, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32307574

RESUMEN

The increasing number of Chromobacterium haemolyticum human infection reports, especially in tropical regions and connected with environmental sources, resulted in an urge to better describe this species. This study aimed to characterize the C. haemolyticum resistome, virulence determinants and genetic platforms related with genome plasticity. A comparative genomic analysis was conducted between clinical C. haemolyticum genomes publicly available and the genome of an environmental isolate obtained in this study. The pangenome of C. haemolyticum was calculated and a total of 3378 core genes were predicted in its core genome, corresponding to 51.7% of the pangenome. Genetic determinants putatively encoding resistance to beta-lactams, fosfomycin, aminoglycosides and trimethoprim were predicted in all genomes, possibly constituting the intrinsic resistome of this species. In terms of resistance to beta-lactams, 4 genes were predicted encoding beta-lactamases of classes A, C and D. Moreover, the analysis of Chromobacterium genomes and C. haemolyticum environmental isolates reinforced the role of this genus as progenitor of the blaKPC gene. Putative virulence factors (VFs) were predicted in all genomes, related to adherence, toxins production, colonization and cell invasion. Secretion systems, including type III, were detected. A significant number of transposases and genomic islands were predicted in C. haemolyticum, in some cases above the average reported for Gram-negative bacterial genomes. We conclude that C. haemolyticum strains, including those of environmental origin, present a noteworthy collection of antibiotic resistance genes and VFs. Furthermore, sequences related to gene mobility and genome plasticity suggest high adaptability potential and a possible role as disseminator of antibiotic resistance.


Asunto(s)
Infecciones Bacterianas/genética , Chromobacterium/genética , Farmacorresistencia Bacteriana Múltiple/genética , Filogenia , Antibacterianos/efectos adversos , Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/microbiología , Chromobacterium/clasificación , Chromobacterium/efectos de los fármacos , Chromobacterium/patogenicidad , Genoma Bacteriano/efectos de los fármacos , Genoma Bacteriano/genética , Genómica , Humanos , Pruebas de Sensibilidad Microbiana , Virulencia/genética
4.
Gene ; 748: 144704, 2020 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-32339624

RESUMEN

Resistance to antibiotics have created havoc around the globe due to the emergence of multi-drug resistant (MDR) pathogenic bacterial strains. To decipher this problem, a detailed understanding of the antimicrobial resistance (AMR) genes and their resistant mechanisms are obligatory. The present study is mainly focused on an opportunistic, nosocomial bacterial strain Enterococcus faecalis V583, which possess acquired exogenous AMR genes portraying resistance against Chloramphenicol, Tetracycline, Vancomycin, Linezolid, Ampicillin and other antibiotics. An interaction network of eight AMR genes along with 40 functional partners have been constructed and analysed. Functional enrichment analysis highlighted 20, 21 and 22 genes having significant roles in Cellular Component (CC), Molecular Functions (MF) and Biological Process (BP) respectively. Clustering analysis resulted in four densely interconnected clusters (C1-C4) which were associated with three AMR mechanisms that include the alteration in drug target (pbps, mur and van genes), complete replacement/bypass of target sites (van genes) and ATP Binding Cassette (ABC) transporter efflux pump mechanisms (msrA, EF_1680, EF_1682 and pbps). Our results showed that the genes responsible for ß-lactams resistance (pbp1A, 1C, 2A, 2B); glycopeptide resistance (ddl, vanBHBRBSBWXYB); Erythromycin, Macrolides, Lincosamide and Streptogramin-B (MLSB) resistance (msrA, EF_1680, EF_1682) along with mur genes (murABBCDEFG) played an important role in MDR mechanisms. Network analysis has shown the genes mraY, pbpC, murE, murG and murD possessed 26, 24, 23, 22 and 22 interactions respectively. With more number of direct interactions, these genes can be considered as hub genes that could be exploited as potential drug targets for new drug discovery.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Enterococcus faecalis/efectos de los fármacos , Redes Reguladoras de Genes , Enterococcus faecalis/genética , Genes Bacterianos
5.
BMC Infect Dis ; 20(1): 314, 2020 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-32345231

RESUMEN

BACKGROUND: Mycoplasma genitalium is an emerging sexually transmitted infection, with increasing rates of resistance to fluroquinolones and macrolides, the recommended treatments. Despite this, M. genitalium is not part of routine screening for Sexually Transmitted Infections (STIs) in many countries and the prevalence of infection and patterns of disease remain to be determined in many populations. Such data is of particular importance in light of the reported rise in antibiotic resistance in M. genitalium isolates. METHODS: Urine and urethral swab samples were collected from the primary public sexual health clinic in Singapore and tested for C. trachomatis (CT) or N. gonorrhoeae (NG) infection and for the presence of M. genitalium. Antibiotic resistance in M. genitalium strains detected was determined by screening for genomic mutations associated with macrolide and fluroquinolone resistance. RESULTS: We report the results of a study into M. genitalium prevalence at the national sexual health clinic in Singapore. M. genitalium was heavily associated with CT infection (8.1% of cases), but present in only of 2.4% in CT negative cases and not independently linked to NG infection. Furthermore, we found high rates of resistance mutations to both macrolides (25%) and fluoroquinolones (37.5%) with a majority of resistant strains being dual-resistant. Resistance mutations were only found in strains from patients with CT co-infection. CONCLUSIONS: Our results support targeted screening of CT positive patients for M. genitalium as a cost-effective strategy to reduce the incidence of M. genitalium in the absence of comprehensive routine screening. The high rate of dual resistance also highlights the need to ensure the availability of alternative antibiotics for the treatment of multi-drug resistant M. genitalium isolates.


Asunto(s)
Antibacterianos/farmacología , Infecciones por Chlamydia/diagnóstico , Chlamydia trachomatis/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple , Infecciones por Mycoplasma/diagnóstico , Mycoplasma genitalium/efectos de los fármacos , Instituciones de Atención Ambulatoria , Antibacterianos/uso terapéutico , Infecciones por Chlamydia/complicaciones , Infecciones por Chlamydia/tratamiento farmacológico , Chlamydia trachomatis/genética , Chlamydia trachomatis/aislamiento & purificación , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Farmacorresistencia Bacteriana Múltiple/genética , Fluoroquinolonas/farmacología , Fluoroquinolonas/uso terapéutico , Humanos , Macrólidos/farmacología , Macrólidos/uso terapéutico , Infecciones por Mycoplasma/complicaciones , Infecciones por Mycoplasma/tratamiento farmacológico , Infecciones por Mycoplasma/epidemiología , Mycoplasma genitalium/genética , Mycoplasma genitalium/aislamiento & purificación , Prevalencia , ARN Ribosómico 23S/química , ARN Ribosómico 23S/genética , ARN Ribosómico 23S/metabolismo , Análisis de Secuencia de ADN , Singapur/epidemiología , Uretra/microbiología
6.
Zhonghua Jie He He Hu Xi Za Zhi ; 43(4): 356-361, 2020 Apr 12.
Artículo en Chino | MEDLINE | ID: mdl-32294818

RESUMEN

Objective: To explore the prevalence risk factors of Beijing genotype Mycobacterium tuberculosis (MTB) in Beijing and its correlation with second-line anti tuberculosis drug resistance. Methods: A total of 1 140 clinical MTB positive strains were collected from various districts in Beijing, and the drug sensitivity was detected by proportion method. Beijing genotype and non Beijing genotype MTB were identified by the method of Spoligotyping. Using SPSS 22.0 statistical software, chi square test or Fisher exact probability test was used to analyze the experimental data. Results: Among 1 140 MTB clinical isolates, 941 (82.5%) were Beijing genotype MTB, 199 were non Beijing genotype MTB. There were 663 males (70.5%) in Beijing genotype and 124 males (62.3%) in non Beijing genotype strains. There were significant differences in the proportion of males between the two genotypes [P=0.021, OR (95% CI):1.442 (1.048-1.985)]. There were 441 floating population (46.9%) in Beijing genotype MTB and 78 floating population (39.2%) in non Beijing genotype MTB. There was a significant difference in the proportion of floating population between the two genotypes [P=0.048,OR (95%CI):1.368(1.001-1.869)]. There were 129 patients (13.7%) aged 65 or older in Beijing genotype MTB, 40 patients (20.1%) aged 65 or older in non Beijing genotype MTB. The difference was statistically significant [P=0.021, or (95% CI): 0.631 (0.426-0.936)]. The resistance drug rates of Levofloxacin (Lfx), Amikacin (Am), Capreomycin (Cm), Para-aminosalicylic (PAS) in Beijing genotypes were 5.5% (52/941), 1.3% (12/941), 3.2% (30/941) and 3.0% (28/941), respectively, and those of non Beijing genotypes were 10.6% (21/199), 8.5% (17/199, 12.6% (25/199) and 11.6% (23/199), the difference was statistically significant (all P<0.05). There were 58 (6.2%) multidrug-resistant (MDR) strains in Beijing genotype MTB and 19 (9.5%) multidrug-resistant strains in non Beijing genotype. There was no significant difference in the proportion of MDR strains between Beijing genotype and non Beijing genotype (P>0.05). Conclusions: Beijing genotype MTB is widespread in Beijing and has a higher proportion in male population and floating population. Compared with non Beijing genotype, Beijing genotype MTB has a lower resistance rate to Lfx, Am, Cm and PAS, and there is no significant difference in the proportion of MDR-TB patients between the two genotypes.


Asunto(s)
Antituberculosos/uso terapéutico , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/genética , Tuberculosis Pulmonar/tratamiento farmacológico , Anciano , Antituberculosos/farmacología , China/epidemiología , ADN Bacteriano/genética , Farmacorresistencia Bacteriana Múltiple/genética , Genotipo , Humanos , Masculino , Mycobacterium tuberculosis/aislamiento & purificación , Prevalencia , Tuberculosis Pulmonar/epidemiología
7.
BMC Infect Dis ; 20(1): 278, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32293315

RESUMEN

BACKGROUND: Understanding potential risks of multi-drug resistant (MDR) pathogens from the booming poultry sector is a crucial public health concern. Campylobacter spp. are among the most important zoonotic pathogens associated with MDR infections in poultry and human. This study systematically examined potential risks and associated socio-environmental factors of MDR Campylobacter spp. in poultry farms and live bird markets (LBMs) of Bangladesh. METHODS: Microbial culture and PCR-based methods were applied to examine the occurrence and MDR patterns of Campylobacter spp. in potential sources (n = 224) at 7 hatcheries, 9 broiler farms and 4 LBMs in three sub-districts. Antimicrobial residues in broiler meat and liver samples (n = 50) were detected by advanced chromatographic techniques. A questionnaire based cross-sectional survey was conducted on socio-environmental factors. RESULTS: Overall, 32% (71/ 224) samples were found contaminated with Campylobacter spp. In poultry farms, Campylobacter spp. was primarily found in cloacal swab (21/49, 43%), followed by drinking water (8/24, 33%), and meat (8/28, 29%) samples of broilers. Remarkably, at LBMs, Campylobacter spp. was detected in higher prevalence (p < 0.05) in broiler meat (14/26, 54%), which could be related (p < 0.01) to bacterial contamination of drinking water (11/21, 52%) and floor (9/21, 43%). Campylobacter isolates, one from each of 71 positive samples, were differentiated into Campylobacter jejuni (66%) and Campylobacter coli (34%). Alarmingly, 49 and 42% strains of C. jejuni and C. coli, respectively, were observed as MDR, i.e., resistant to three or more antimicrobials, including, tetracycline, amoxicillin, streptomycin, fluoroquinolones, and macrolides. Residual antimicrobials (oxytetracycline, ciprofloxacin and enrofloxacin) were detected in majority of broiler liver (79%) and meat (62%) samples, among which 33 and 19%, respectively, had concentration above acceptable limit. Inadequate personal and environmental hygiene, unscrupulously use of antimicrobials, improper waste disposal, and lack of health surveillance were distinguishable risk factors, with local diversity and compound influences on MDR pathogens. CONCLUSION: Potential contamination sources and anthropogenic factors associated with the alarming occurrence of MDR Campylobacter, noted in this study, would aid in developing interventions to minimize the increasing risks of poultry-associated MDR pathogens under 'One Health' banner that includes poultry, human and environment perspectives.


Asunto(s)
Antibacterianos/análisis , Infecciones por Campylobacter/epidemiología , Campylobacter coli/efectos de los fármacos , Campylobacter jejuni/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Granjas , Enfermedades de las Aves de Corral/epidemiología , Aves de Corral/microbiología , Animales , Antibacterianos/uso terapéutico , Bangladesh/epidemiología , Infecciones por Campylobacter/tratamiento farmacológico , Infecciones por Campylobacter/microbiología , Campylobacter coli/genética , Campylobacter coli/aislamiento & purificación , Campylobacter jejuni/genética , Campylobacter jejuni/aislamiento & purificación , Pollos/microbiología , Estudios Transversales , Humanos , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , Prevalencia , Factores de Riesgo
8.
BMC Infect Dis ; 20(1): 237, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-32192451

RESUMEN

BACKGROUND: Infections with multidrug-resistant organisms (MDRO) pose a serious threat to patients with dysregulated immunity such as in hemophagocytic lymphohistiocytosis (HLH), but such infections have rarely been comprehensively characterized. Here, we present a fatal case of HLH secondary to cytomegalovirus (CMV) infection complicated by both anti-viral drug resistance and sepsis from multiple MDROs including pandrug-resistant superbug bacteria. CASE PRESENTATION: A previously healthy, six-year-old boy presented with a 45-day history of fever prior to a diagnosis of hemophagocytic lymphohistiocytosis and hemorrhagic colitis, both associated with CMV. On hospital admission, the patient was found to be colonized with multiple, multidrug-resistant (MDR) bacteria including vancomycin-resistant enterococci (VRE) and carbapenamase-producing organisms (CPO). He eventually developed respiratory, urine and bloodstream infections with highly drug-resistant, including pandrug-resistant bacteria, which could not be controlled by antibiotic treatment. Antiviral therapy also failed to contain his CMV infection and the patient succumbed to overwhelming bacterial and viral infection. Whole genome sequencing (WGS) of the MDR bacteria and metagenomic analysis of his blood sample revealed an unusual accumulation of a wide range of antimicrobial resistance mechanisms in a single patient, including antiviral resistance to ganciclovir, and resistance mechanisms to all currently available antibiotics. CONCLUSIONS: The case highlights both the risk of acquiring MDR superbugs and the severity of these infections in HLH patients.


Asunto(s)
Infecciones por Citomegalovirus/complicaciones , Citomegalovirus/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Farmacorresistencia Viral Múltiple , Linfohistiocitosis Hemofagocítica/virología , Sepsis/mortalidad , Antibacterianos/efectos adversos , Antibacterianos/uso terapéutico , Antivirales/efectos adversos , Antivirales/uso terapéutico , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Niño , Citomegalovirus/genética , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/diagnóstico , Infecciones por Citomegalovirus/tratamiento farmacológico , Infecciones por Citomegalovirus/virología , Resultado Fatal , Ganciclovir/efectos adversos , Ganciclovir/uso terapéutico , Genotipo , Humanos , Linfohistiocitosis Hemofagocítica/diagnóstico , Linfohistiocitosis Hemofagocítica/tratamiento farmacológico , Masculino , Sepsis/tratamiento farmacológico , Sepsis/microbiología , Enterococos Resistentes a la Vancomicina/efectos de los fármacos , Enterococos Resistentes a la Vancomicina/genética
9.
Zhonghua Jie He He Hu Xi Za Zhi ; 43(3): 234-241, 2020 Mar 12.
Artículo en Chino | MEDLINE | ID: mdl-32164095

RESUMEN

Objective: To evaluate the use of multiplex PCR amplicon sequencing (mPCR-NGS) technology in detecting gene mutations related to drug resistance of Mycobacterium tuberculosis (MTB) in formalin-fixed paraffin-embedded tissue specimens, and to explore its clinical value in the diagnosis of drug-resistant tuberculosis. Methods: Fifty clinical MTB strains isolated in the Changping District Tuberculosis Control Institute of Beijing from April 2013 to October 2015 with drug susceptibility test (DST) results of rifampicin, isoniazid, ethambutol, streptomycin, ofloxacin, capreomycin, kanamycin and amikacin available were recovered, including 42 drug-resistant strains and 8 drug-sensitive strains. The mPCR-NGS test was established to detect genes related to the 8 anti-tuberculosis drugs according to the previously published studies and databases. Fifty-five paraffin-embedded tissue specimens from drug-resistant tuberculosis patients were collected in the Department of Pathology, Beijing Chest Hospital, Capital Medical University during November 2017 to September 2018. All the specimens showed no less than one mutation in the gene regions related to drug resistance of any of the 4 drugs (rifampicin, isoniazid, ethambutol or fluoroquinolones) by probe melting curve assay. The effectiveness of mPCR-NGS test was evaluated on clinical MTB isolates using phenotypic DST as the reference. Clinical evaluation of mPCR-NGS test on formalin-fixed paraffin-embedded specimens from TB patients was performed using probe melting curve assay as the reference. The sensitivity, specificity and coincidence of mPCR-NGS were analyzed. Results: Using phenotypic DST as the reference, the sensitivities of the mPCR-NGS for detecting drug-resistance of rifampicin, isoniazid, streptomycin, and ethambutol were 95% (38/40), 93% (27/29), 93% (27/29), and 72% (13/18), respectively; and the specificities were 100% (10/10), 95% (20/21), 100% (21/21), and 94% (30/32), respectively. The sensitivities for capreomycin, kanamycin and amikacin were all 100% (2/2, 3/3, 3/3), and the specificities were 98% (47/48), 100% (33/33) and 100% (47/47), respectively. The sensitivity and specificity of ofloxacin were 70% (7/10) and 100% (40/40), respectively. The total coincidence rate for the 8vdrugs was 94%, and the Kappa value was 0.87. The 55 paraffin-embedded tissue specimens included in this study were all tested by probe melting curve assays. Among them 28 were resistant to rifampicin, 37 resistant to isoniazid, 13 resistant to ethambutol, and 17 resistant to fluoroquinolones. Using the probe melting curve assay as the reference, the sensitivities of the mPCR-NGS for detecting resistant to rifampicin, isoniazid, ethambutol, and fluoroquinolones were 100% (28/28), 95% (35/37), 100%, and 100%, respectively; and the specificities were all 100% (42/42, 38/38). The total coincidence rate of the two methods was 99%, and the Kappa value was 0.98. Conclusions: mPCR-NGS showed good sensitivities and specificities in detecting drug-resistant gene mutations both in clinical MTB isolates and paraffin-embedded tissue specimens. mPCR-NGS has the potential to be an accurate and rapid molecular pathological technology for diagnosis of drug-resistant tuberculosis.


Asunto(s)
Antituberculosos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Genes Bacterianos , Secuenciación de Nucleótidos de Alto Rendimiento , Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/genética , Humanos , Pruebas de Sensibilidad Microbiana , Mutación , Adhesión en Parafina , Sensibilidad y Especificidad
10.
Ann Clin Microbiol Antimicrob ; 19(1): 10, 2020 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-32220258

RESUMEN

BACKGROUND: Staphylococcus aureus is a primary pathogen of orthopedic infections. By mediating antimicrobial resistance, S. aureus biofilm plays an important role in the recalcitrance of orthopedic infections, especially for the intractable osteomyelitis (OM). This study investigated the relationship between biofilm production and various genetic or phenotypic characteristics among orthopedic S. aureus strains. METHODS: A total of 137 orthopedic S. aureus isolates were enrolled and divided into OM and non-OM groups. Biofilm production was evaluated using the crystal violet assay. Genetic and phenotypic characteristics including MRSA identification, MLST and spa typing, carriage of virulence genes, drug resistance, and patients' inflammatory responses indicators were characterized. The relationship between biofilm production and above-mentioned features was respectively analyzed among all isolates and compared between OM and non-OM isolates. RESULTS: Biofilm production presented no significant difference between OM (including 9 MRSA isolates) and non-OM (including 21 MRSA isolates) strains. We found that ST88, t377 and ST630-MSSA-t377 strains produced very strong biofilms, while MLST types of ST15, ST25, ST398, ST5, ST59 and spa types of t002, t2325, t437 tended to produce weaker biofilms. Strains with the following profiles produced stronger biofilms: fib(+)-hlgv(+)-lukED(+)-sei(-)-sem(-)-seo(-) for all isolates, sei(-)-sem(-)-seo(-) for OM isolates, and cna (+)-fib (+)-hlgv (+)-lukED (+)-seb(-)-sed(-) for non-OM isolates. In addition, not any single drug resistance was found to be related to biofilm production. We also observed that, among OM patients, strains with stronger biofilms caused weaker inflammatory responses. CONCLUSION: Some genetic or phenotypic characteristics of orthopedic strains were associated with biofilm production, and this association could be different among OM and non-OM strains. The results are of great significance for better understanding, evaluating and managing different kinds of biofilm-associated orthopedic infections, and provide potential targets for biofilm clearance.


Asunto(s)
Biopelículas , Enfermedades Musculoesqueléticas/microbiología , Infecciones Estafilocócicas , Staphylococcus aureus , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Farmacorresistencia Bacteriana Múltiple/genética , Genotipo , Humanos , Staphylococcus aureus Resistente a Meticilina/genética , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Enfermedades Musculoesqueléticas/tratamiento farmacológico , Osteomielitis/tratamiento farmacológico , Osteomielitis/microbiología , Fenotipo , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Factores de Virulencia/genética
11.
Artículo en Inglés | MEDLINE | ID: mdl-32049255

RESUMEN

In Fortaleza, the capital of Ceara State, Brazil, the detection rate of tuberculosis (TB) in 2018 was 65.5/100,000 inhabitants with a cure rate of 59.1%, which is higher than the country average. This study investigated the risk factors associated with drug-resistant tuberculosis (DR-TB) and identified the drug-resistance phenotype and resistance-conferring mutations. The geographic distribution of DR-TB in Fortaleza, Brazil, was also determined. From March 2017 to February 2018, 41 DR-TB isolates and 69 drug-susceptible pulmonary TB isolates were obtained from patients seen at a referral hospital in Fortaleza, Brazil. Samples were subjected to phenotypic and genetic analysis of resistance; the spatial distribution of the participants was also analyzed. Primary resistance was high (50.9%) among participants. The following risk factors for DR were identified: being female ( p = 0.03), having diabetes ( p < 0.01), history of previous TB disease ( p < 0.01), and the number of intra-domiciliary contacts ( p < 0.01). Analysis by multiplex allele-specific polymerase chain reaction detected mutations in the genes katG (65.8%) , rpoB (43.9%), inhA promoter (14.6%), and gyrA (9.8%). Sequencing identified mutations in the the genes katG (75.6%), inhA promoter (19.5%), rpoB (85.4%), and gyrA (100%). There was no mutation in the rrs gene. Spatial analysis showed DR-TB isolates distributed in areas of low socioeconomic status in the city of Fortaleza. Our results emphasized the importance of detecting resistance to TB drugs. The resistance found in the gene gyrA is of concern due to the high number of pre-extensive DR-TB cases in Fortaleza.


Asunto(s)
Antituberculosos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Mutación/genética , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Adulto , Estudios de Casos y Controles , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Femenino , Genotipo , Geografía Médica , Humanos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa Multiplex , Mycobacterium tuberculosis/aislamiento & purificación , Fenotipo , Embarazo , Estudios Prospectivos , Factores de Riesgo , Factores Socioeconómicos
12.
J Infect Public Health ; 13(4): 647-650, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32067931

RESUMEN

Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae have been isolated from human patients in many countries across the globe but rarely in Saudi Arabia. Here we provide the genomic characterization of the first KPC-producing K. pneumoniae isolated from the urine of a patient in Riyadh, Saudi Arabia, who had a recent travel history to Egypt involving a medical procedure. Presence of KPC-encoding gene initially detected with the Xpert Carba-R assay was confirmed by traditional PCR. Susceptibility testing using the VITEK 2 system, E-test and microbroth dilution methods showed that the K. pneumoniae isolate, namely SA01_KPC-2, was resistant to all antibiotics except colistin and ceftazidime/avibactam. Whole-genome sequencing (WGS), performed on the Illumina Miseq instrument, identified the isolate as sequence type (ST) 383 and serotype KL30-D1 O1v2. Genome assembly of SA01_KPC-2 indicated the presence of two plasmids. Plasmid pSA01_KPC-2, of approximately 45.9 kb in size, harbored the blaKPC-2 flanked by ISKpn27 and ISKpn6 and had a backbone similar to published KPC-carrying IncX6 plasmids. The second plasmid pSA01_incHIB1, a derivative of published 372-kb plasmid pKpvST383, carried genes encoding virulence factors and resistance to five classes of antibiotics. The isolation of the first KPC producer in Saudi Arabia requires high attention and rapid interventions to prevent further spread.


Asunto(s)
Proteínas Bacterianas/genética , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/enzimología , beta-Lactamasas/genética , Anciano , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Masculino , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , Arabia Saudita/epidemiología , Secuenciación Completa del Genoma
13.
Poult Sci ; 99(2): 1117-1123, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32029147

RESUMEN

Colibacillosis, caused by Escherichia coli, is one of the most common bacterial diseases of chickens. The high incidence and considerable economic losses associated with colibacillosis make it a significant concern worldwide. In recent years, the efficacy of colistin has been severely impacted by the emergence of plasmid-mediated colistin resistance genes, especially mcr-1. Therefore, monitoring of antibiotic resistance, particularly colistin resistance, amongst E. coli strains is vitally important to the future growth and sustainability of the poultry industry. In this study, a total of 130 E. coli strains were isolated from the livers of chickens displaying symptoms of colibacillosis in Tai'an, China. Isolates were screened for their susceptibility to various antibiotics and for the presence of mobile colistin resistance genes and other antibiotic resistance genes. Overall, 75 (57.7%) isolates showed resistance to colistin and were positive for mcr-1. The mobile colistin resistance genes, mcr-2, -3, and -4, were not detected in this study. Of the 75 mcr-1-positive isolates, all (100%) also carried tetracycline resistance genes, 71 (94.7%) also contained genes associated with ß-lactam resistance, 59 (78.7%) contained aminoglycoside resistance genes, and 57 (76%) contained sulfonamide resistance genes. This high prevalence of multidrug resistance among mcr-1-positive E. coli isolates, including the production of extended-spectrum ß-lactamases, is highly concerning. The surveillance findings presented here will be conducive to our understanding of the prevalence and characteristics of multidrug-resistance in E. coli in the Tai'an area and will provide a better scientific basis for the clinical treatment of colibacillosis in chickens.


Asunto(s)
Pollos , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Escherichia coli/veterinaria , Escherichia coli/efectos de los fármacos , Enfermedades de las Aves de Corral/epidemiología , Animales , China/epidemiología , Escherichia coli/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Pruebas de Sensibilidad Microbiana/veterinaria , Enfermedades de las Aves de Corral/microbiología , Prevalencia
14.
Int J Nanomedicine ; 15: 199-213, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32021174

RESUMEN

Purpose: Resistance to antibiotics is a major problem of public health. One of the alternative therapies is silver - more and more popular because of nanotechnology development and new possibilities of usage. As a component of colloid, powder, cream, bandages, etc., nanosilver is often recommended to treat the multidrug-resistant pathogens and we can observe its overuse also outside of the clinic where different physicochemical forms of silver nanoformulations (e.g. size, shape, compounds, surface area) are introduced. In this research, we described the consequences of long-term bacteria exposure to silver nanoformulations with different physicochemical properties, including changes in genome and changes of bacterial sensitivity to silver nanoformulations and/or antibiotics. Moreover, the prevalence of exogenous resistance to silver among multidrug-resistant bacteria was determined. Materials and Methods: Gram-negative and Gram-positive bacteria strains are described as sensitive and multidrug-resistant strains. The sensitivity of the tested bacterial strains to antibiotics was carried out with disc diffusion methods. The sensitivity of bacteria to silver nanoformulations and development of bacterial resistance to silver nanoformulations has been verified via determination of the minimal inhibitory concentrations. The presence of sil genes was verified via PCR reaction and DNA electrophoresis. The genomic and phenotypic changes have been verified via genome sequencing and bioinformatics analysis. Results: Bacteria after long-term exposure to silver nanoformulations may change their sensitivity to silver forms and/or antibiotics, depending on the physicochemical properties of silver nanoformulations, resulting from phenotypic or genetic changes in the bacterial cell. Finally, adaptants and mutants may become more sensitive or resistant to some antibiotics than wild types. Conclusion: Application of silver nanoformulations in the case of multiple resistance or multidrug-resistant bacterial infection can enhance or decrease their resistance to antibiotics. The usage of nanosilver in a clinic and outside of the clinic should be determined and should be under strong control. Moreover, each silver nanomaterial should be considered as a separate agent with a potential different mode of antibacterial action.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Nanoestructuras/química , Plata/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Bacterias Gramnegativas/genética , Bacterias Grampositivas/genética , Pruebas de Sensibilidad Microbiana , Plata/química
15.
J Med Microbiol ; 69(3): 379-386, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32101158

RESUMEN

Introduction. Despite many ongoing surveillance projects and the recent focus on the veterinary and clinical 'One Health' aspects of antimicrobial resistance (AMR), evidence of the extent of any public health risk posed by animal reservoirs with respect to the transmission of resistant strains of Escherichia coli to humans remains varied and contentious. In the UK, the main zoonotic reservoir for the foodborne pathogen Shiga toxin-producing E. coli (STEC) is cattle and sheep. In this study, we adopt an alternative approach to the risk assessment of transmission of AMR E. coli from animals to humans, involving monitoring AMR in isolates of STEC, an established zoonotic, foodborne pathogen, from human cases of gastrointestinal disease.Aim. The aim of this study was to determine the genome-derived AMR profiles for STEC from human cases to assess the risk of transmission of multidrug-resistant STEC from ruminants to humans.Methodology. STEC belonging to 10 different clonal complexes (CCs) (n=457) isolated from human faecal specimens were sequenced and genome-derived AMR profiles were determined. Phenotypic susceptibility testing was undertaken on all isolates (n=100) predicted to be resistant to at least one class of antimicrobial.Results. Of the 457 isolates, 332 (72.7 %) lacked identifiable resistance genes and were predicted to be fully susceptible to 11 classes of antimicrobials; 125/332 (27.3 %) carried 1 or more resistance genes, of which 83/125 (66.4 %) were resistant to 3 or more classes of antibiotic. The percentage of isolates harbouring AMR determinants varied between CCs, from 4% in CC25 to 100% in CC504. Forty-six different AMR genes were detected, which conferred resistance to eight different antibiotic classes. Resistance to ampicillin, streptomycin, tetracyclines and sulphonamides was most commonly detected. Four isolates were identified as extended-spectrum ß-lactamase producers. An overall concordance of 97.7 % (n=1075/1100) was demonstrated between the phenotypic and genotypic methods.Conclusion. This analysis provided an indirect assessment of the risk of transmission of AMR gastrointestinal pathogens from animals to humans, and revealed a subset of human isolates of the zoonotic pathogen STEC were resistant to the antimicrobials used in animal husbandry. However, this proportion has not increased over the last three decades, and thismay provide evidence that guidancepromoting responsible practice has been effective.


Asunto(s)
Antibacterianos/farmacología , Reservorios de Enfermedades/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Escherichia coli/epidemiología , Genoma Bacteriano/genética , Escherichia coli Shiga-Toxigénica/genética , Animales , Bovinos , Inglaterra/epidemiología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/transmisión , Heces/microbiología , Genotipo , Humanos , Masculino , Salud Única , Minorías Sexuales y de Género , Ovinos , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Zoonosis
16.
Mikrobiyol Bul ; 54(1): 40-49, 2020 01.
Artículo en Turco | MEDLINE | ID: mdl-32050877

RESUMEN

Acinetobacter baumannii is a multi-drug resistant (MDR) gram-negative pathogen leading to nosocomial infections. Hospital-acquired infections due to A.baumannii occur especially in patients hospitalized in intensive care units. Important infections related to this bacterium are pneumonia, bacteremia, endocarditis, skin and soft tissue, urinary tract infections and meningitis. Human transmission is usually through the hospital environment or through medical personnel. A.baumannii isolates increases their virulence not only being multiple resistance to antibiotics but as well as the ability to form biofilm. The biofilm formation of A.baumannii isolates were mostly related with genes encoding curli fiber (csgA), the chaperone-usher fimbria (csuE) and the outer membrane (ompA). The aim of this study was to demonstrate biofilm production and virulence genes in MDR invasive A.baumannii isolates. MDR and similarity status previously known invasive A.baumannii (n= 156) isolates were included in the study. Biofilm production was determined by quantitative microplate biofilm method. Virulence genes csgA, csuE, fimH, ompA and blaPER-1 were investigated by polymerase chain reaction (PCR). It was determined that 60.3% (94/156) of all the isolates formed biofilm. Of these 94 isolates, 17 were weak, 33 were medium and 44 were strong. The mean biomass forming capacity of the isolates was found to be 2.23 ± 0.0033. Among the isolates included in the study (n= 156) the frequency of csgA, csuE, ompA, fimH and blaPER-1 genes were 71.2%, 32.1%, 21.8%, 7.1% and 3.2% respectively. The frequency of csgA, ompA, bap, csuE, fimH virulence genes were found to be 41.5%, 24.5%, 20.2% and 5.3% among biofilm positive isolates respectively. Biofilm-forming isolates were most commonly found in pulsotype II 19.1% (18/94), pulsotype IX 17.0% (16/94) and pulsotype VI 12.8% (12/94). In this study, when the distribution of virulence genes were compAred with the isolates that have weak, medium and strong biofilm, all of the studied genes were found to be more abundant in isolates with strong and medium positive biofilm production. This has shown that excluding fimH gene, csgA, csuE and ompA genes have contributed to the biofilm formation in invasive A.baumannii isolates, respectively.


Asunto(s)
Infecciones por Acinetobacter , Acinetobacter baumannii , Biopelículas , Farmacorresistencia Bacteriana Múltiple , Virulencia , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Virulencia/genética
17.
PLoS One ; 15(2): e0220428, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32101543

RESUMEN

BACKGROUND: Multidrug-resistant (MDR) E. coli with extended-spectrum ß-lactamases (ESBLs) is becoming endemic in health care settings around the world. Baseline data on virulence and antimicrobial resistance (AMR) of specific lineages of E. coli circulating in developing countries like India is currently lacking. METHODS: Whole-genome sequencing was performed for 60 MDR E. coli isolates. The analysis was performed at single nucleotide polymorphism (SNP) level resolution to identify the presence of their virulence and AMR genes. RESULTS: Genome comparison revealed the presence of ST-131 global MDR and ST410 as emerging-MDR clades of E. coli in India. AMR gene profile for cephalosporin and carbapenem resistance differed between the clades. Genotypes blaCTX-M-15 and blaNDM-5 were common among cephalosporinases and carbapenemases, respectively. For aminoglycoside resistance, rmtB was positive for 31.7% of the isolates, of which 95% were co-harboring carbapenemases. In addition, the FimH types and virulence gene profile positively correlated with the SNP based phylogeny, and also revealed the evolution of MDR clones among the study population with temporal accumulation of SNPs. The predominant clone was ST167 (blaNDM lineage) followed by ST405 (global clone ST131 equivalent) and ST410 (fast spreading high risk clone). CONCLUSIONS: This is the first report on the whole genome analysis of MDR E. coli lineages circulating in India. Data from this study will provide public health agencies with baseline information on AMR and virulent genes in pathogenic E. coli in the region.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli/genética , Genómica , Virulencia/genética , Secuenciación Completa del Genoma , Carbapenémicos/farmacología , Cefalosporinas/farmacología , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Humanos , India , Polimorfismo de Nucleótido Simple
18.
Helicobacter ; 25(2): e12684, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32074664

RESUMEN

BACKGROUND: Resistant Helicobacter pylori to commonly used antimicrobial agents are associated with severe upper gastrointestinal disorders. To provide an epidemiological picture of H pylori and characterize the resistance pattern and genetic variation of clinical isolates, stomach biopsies from patients with functional dyspepsia were evaluated in northeast of Iran. MATERIALS AND METHODS: In this study, 80 patients were recruited. Finally, fifty H pylori strains were isolated from antrum and corpus biopsies by culturing on Columbia agar. All strains were identified by standard laboratory procedures. Susceptibility testing of antibiotics was performed using minimum inhibitory concentration test. Allele-specific primer (ASP)-PCR of 23S rRNA which associated with clarithromycin resistance was done among resistant strains. Moreover, cagA gene and polymorphism in vacA were detected. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) was applied to investigate the genetic variations among all strains. RESULTS: Antibiotic resistance pattern of H pylori strains was as follows: 68% (34/50) to metronidazole, 50% (25/50) to rifampicin, 30% (15/50) to amoxicillin, 28% (14/50) to levofloxacin, 22% (11/50) to clarithromycin, and 16% (8/50) to tetracycline. Multidrug-resistant strains were observed in 19 strains (38%). ASP-PCR of 23S rRNA showed four strains had A2143G mutation, six strains had A2142G mutation, and one strain had a Wt+A2143G mutation. Amplification of virulence-associated genes revealed that cagA was present in 27 isolates (54%) and vacA in 36 isolates (72%). The most common genotype of H pylori was vacA s1am2 (40%) followed by vacA s2m2 (14%), vacA s1am1 (12%), vacA s1bm1 (4%), and vacA s1bm2 (2%). DNA fingerprinting pattern indicated a high heterogeneity among isolated strains. CONCLUSION: An alarming level of resistance to metronidazole and rifampicin and high heterogeneity among H pylori isolates highlighted the importance of continued monitoring of antimicrobial susceptibility and epidemiological surveillance of this pathogen.


Asunto(s)
Farmacorresistencia Bacteriana/genética , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Helicobacter , Helicobacter pylori , Virulencia/genética , Adulto , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Biopsia , Femenino , Variación Genética , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Humanos , Irán/epidemiología , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , ARN Ribosómico 23S/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Estómago/microbiología
19.
PLoS One ; 15(2): e0228877, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32050009

RESUMEN

The efflux pumps from the Resistance-Nodulation-Division family, RND, are main contributors to intrinsic antibiotic resistance in Gram-negative bacteria. Among this family, the MdtABC pump is unusual by having two inner membrane components. The two components, MdtB and MdtC are homologs, therefore it is evident that the two components arose by gene duplication. In this paper, we describe the results obtained from a phylogenetic analysis of the MdtBC pumps in the context of other RNDs. We show that the individual inner membrane components (MdtB and MdtC) are conserved throughout the Proteobacterial species and that their existence is a result of a single gene duplication. We argue that this gene duplication was an ancient event which occurred before the split of Proteobacteria into Alpha-, Beta- and Gamma- classes. Moreover, we find that the MdtABC pumps and the MexMN pump from Pseudomonas aeruginosa share a close common ancestor, suggesting the MexMN pump arose by another gene duplication event of the original Mdt ancestor. Taken together, these results shed light on the evolution of the RND efflux pumps and demonstrate the ancient origin of the Mdt pumps and suggest that the core bacterial efflux pump repertoires have been generally stable throughout the course of evolution.


Asunto(s)
Proteínas Bacterianas/genética , Duplicación de Gen/genética , Proteobacteria/genética , Pseudomonas aeruginosa/genética , Farmacorresistencia Bacteriana Múltiple/genética , Proteínas de Transporte de Membrana/genética , Filogenia
20.
PLoS One ; 15(2): e0228956, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32040533

RESUMEN

Listeria monocytogenes (L. monocytogenes) is a foodborne pathogen and the etiologic agent of listeriosis, which can be disseminated within the agricultural environment particularly soil and irrigation water, contaminate farm produce and cause high mortality and morbidity among vulnerable individuals. This study assessed the incidence and antibiogram of L. monocytogenes recovered from irrigation water and agricultural soil samples collected from Chris Hani and Amathole District Municipalities (DMs) in Eastern Cape Province, South Africa. The distribution of presumptive L. monocytogenes in irrigation water and agricultural soil samples was done using the standard plate count method, while polymerase chain reaction (PCR) was used to identify the isolates. The confirmed isolates were screened for 9 key virulence markers using PCR after which they were subjected to antibiotic susceptibility testing against 18 antibiotics used for the alleviation of listeriosis using the disk diffusion method. Relevant putative antibiotic resistance genes in the resistant variants were screened for using PCR. The distribution of L. monocytogenes in irrigation water samples was statistically significant (P ≤ 0.05) and ranged from log10 1.00 CFU/100ml to log10 3.75 CFU/100 ml. In agricultural soil samples, the distribution ranged significantly (P ≤ 0.05) from log10 2.10 CFU/g to log10 3.51 CFU/g. Of the 117 presumptive L. monocytogenes recovered from irrigation water samples and 183 presumptive L. monocytogenes isolated from agricultural soil samples, 8 (6.8%) and 12 (6.6%) isolates were confirmed respectively. Nine virulence genes including inlA, inlB, inlC, inlJ, actA, hlyA, plcA, plcB, and iap were detected in all the isolates. The proportion of the isolates exhibiting phenotypic resistance against the test antimicrobials followed the order: tetracycline (90%), doxycycline (85%), cefotaxime (80%), penicillin (80%), chloramphenicol (70%), linezolid (65%), erythromycin (60%) and trimethoprim/sulfamethoxazole (55%). The isolates exhibited multiple antibiotic resistance against 3 or more antibiotics and the MAR indices of all the multidrug isolates were ≥0.2. The isolates harboured antibiotic resistance genes including tetA, tetB, tetC, sulI, sulII, aadA, aac(3)-IIa and ESBLs including blaTEM, blaCTX-M group 9, blaVEB as well as AmpC. None of the isolates harboured the carbapenemases. We conclude that irrigation water and agricultural soil collected from Chris Hani and Amathole District Municipalities (DMs) in Eastern Cape Province of South Africa are reservoirs and potential transmission routes of multidrug-resistant L. monocytogenes to the food web and consequently threat to public health.


Asunto(s)
Listeria monocytogenes/aislamiento & purificación , Microbiología del Suelo , Microbiología del Agua , Riego Agrícola , Reservorios de Enfermedades/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Granjas , Microbiología de Alimentos , Genes Bacterianos , Humanos , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/genética , Listeriosis/transmisión , Pruebas de Sensibilidad Microbiana , Sudáfrica , Virulencia/genética
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