RESUMO
Nosocomial outbreaks of Burkholderia cepacia complex, transmitted through contaminated medical surfaces or equipment have been reported. Pulsed-field Gel Electrophoresis (PFGE) is recognized as the "gold standard" for molecular subtyping, yet studies on clonal relationships in India are limited. PFGE was used to study the clonal relationships of 22 isolates of Burkholderia cenocepacia from 12 patients admitted to a critical care unit during 2 months (November and December 2021). PFGE revealed three different profiles with 15 isolates belonging to a single cluster suggesting a common source within the hospital, emphasizing the need for preventive measures to control B. cenocepacia transmission.
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Infecções por Burkholderia , Burkholderia cenocepacia , Infecção Hospitalar , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado , Unidades de Terapia Intensiva , Centros de Atenção Terciária , Humanos , Infecções por Burkholderia/epidemiologia , Infecções por Burkholderia/microbiologia , Burkholderia cenocepacia/genética , Burkholderia cenocepacia/classificação , Burkholderia cenocepacia/isolamento & purificação , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Índia/epidemiologia , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Tipagem Molecular/métodosRESUMO
PURPOSE: Burkholderia cepacia complex (Bcc) is a diverse group of environmental bacteria associated with opportunistic infections. The identification of Bcc using conventional methods poses challenges. Bcc infections are difficult to treat due to intrinsic antibiotic resistance. The study aimed to investigate the species distribution and antimicrobial susceptibility of clinical Bcc isolates. METHODS: A total of 153 Bcc isolates obtained from clinical samples were analysed. Species identification was carried out using automated methods, including MALDI-TOF MS and VITEK2. Antimicrobial susceptibility testing was performed using the disc diffusion method. RESULTS: Burkholderia cenocepacia (70.5%) emerged as the most prevalent species, followed by Burkholderia contaminans (9.8%) and Burkholderia cepacia (7.2%). Ventilator-associated pneumonia (38.6%) was the most common infection, followed by sepsis (28.1%). Co-existence of Bcc with other pathogens in many cases suggested potential co-infection scenarios. Antimicrobial susceptibility revealed that ceftazidime, co-trimoxazole and meropenem were the most effective drugs, while levofloxacin proved to be the least effective. Moderate susceptibility was noted to minocycline, with 4.6% of isolates exhibiting multi-drug resistance. CONCLUSION: This study provides valuable insights into the prevalence, clinical associations, and antibiotic susceptibility of Bcc in India. It highlights the importance of Bcc as a nosocomial pathogen, especially in vulnerable patient populations. The findings contribute to understanding Bcc infections, their distribution, and emphasize the necessity for accurate identification methods in clinical settings.
Assuntos
Antibacterianos , Infecções por Burkholderia , Complexo Burkholderia cepacia , Testes de Sensibilidade Microbiana , Centros de Atenção Terciária , Humanos , Índia/epidemiologia , Infecções por Burkholderia/microbiologia , Complexo Burkholderia cepacia/efeitos dos fármacos , Complexo Burkholderia cepacia/isolamento & purificação , Complexo Burkholderia cepacia/classificação , Antibacterianos/farmacologia , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Idoso , Criança , Pré-Escolar , Lactente , Pneumonia Associada à Ventilação Mecânica/microbiologia , Sepse/microbiologia , Idoso de 80 Anos ou mais , Coinfecção/microbiologia , Ceftazidima/farmacologiaRESUMO
Linezolid is an effective oxazolidinone antibiotic against multi resistant Gram-positive organisms. Linezolid resistance is an emerging problem and some controversy exists about the reliability of different phenotypic methods of linezolid susceptibility testing. Fifty isolates each of methicillin resistant S. aureus (MRSA) and Staphylococcus haemolyticus were tested for linezolid susceptibility using Kirby-Bauer disc diffusion, E-test, automated system VITEK2, Broth micro-dilution (reference method) and PCR for the cfr gene. Six resistant isolates were identified, three each in MRSA and S. haemolyticus, all carrying the cfr gene. E-test and VITEK2 were found to be more accurate than disc diffusion test.
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Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Linezolida/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Reprodutibilidade dos Testes , Antibacterianos/farmacologia , Staphylococcus , Testes de Sensibilidade MicrobianaRESUMO
Among the species within Acb-complex, Acinetobacter lactucae has not been frequently isolated from clinical settings, unlike Acinetobacter baumannii, which is an important nosocomial pathogen. We report the genomic sequences of A. lactucae strains (PKAL1732 and 1828C) harboring multiple-resistance determinants including metallo-ß-lactamase (bla NDM-1) isolated from immunocompromised patients admitted to a referral hospital in India.
RESUMO
BACKGROUND: Most studies on biocide resistance and its genetic determinants arise from environmental or food-borne microbial isolates and only a few from clinically relevant isolates. OBJECTIVES: This study determines the proportion of biocide resistance against five commonly used biocides and detects biocide resistance genes among MDR bacterial isolates using PCR. METHODS: Consecutive MDR isolates (n â= â180) were included (30 each of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, and Enterococcus species) from clinical specimens of various inpatient units at JIPMER. The isolates were challenged at 0.5,1 and 2 Macfarland (McF) inoculum with discrete dilutions of disinfectants. The minimum bactericidal concentrations (MBCs) for 70% Ethanol, 1.5% Cresol, 2% Glutaraldehyde, 1% Cetrimide, and 1% Chlorhexidine were determined for the isolates using ATCC reference strains as controls. PCR was performed targeting qac A/B, G; smr; and nfx B genes. RESULTS: For all biocides, MDR isolates had MBCs less than the maximum MBCs of ATCC strains. For MDR K. pneumoniae, A. baumannii, and P. aeruginosa, the highest MBCs of chlorhexidine and cetrimide were ≥75 and â≥ â150 âµg/ml respectively at 0.5 McF inoculum; whereas these organisms grew at higher inoculum (2McF) even at commercially recommended biocidal concentration (1%) corresponding to 750 and 1500 âµg/ml of chlorhexidine and cetrimide respectively. Meanwhile, the highest MBCs of MDR E. coli were 75 and 150 âµg/ml for chlorhexidine and cetrimide respectively. Interestingly, the Gram-positive cocci survived the action of up to 35% ethanol. The nfxB and qacG genes were detected in 87% and 6.67% of MDR P. aeruginosa isolates respectively with no biocide resistance genes detected among the other organisms. CONCLUSIONS: Biocide dilutions challenged with higher inoculum indicated a narrow margin of effectiveness for certain biocides. Although a significant proportion of clinical MDR isolates of P. aeruginosa harbored biocide resistance genes, this finding had no phenotypic correlation.
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Desinfetantes , Humanos , Desinfetantes/farmacologia , Clorexidina , Escherichia coli , Centros de Atenção Terciária , Testes de Sensibilidade Microbiana , Etanol , Compostos de Cetrimônio , Antibacterianos/farmacologiaRESUMO
Introduction. Linezolid is an effective therapeutic option for treating severe infections caused by multidrug-resistant Gram-positive organisms. Several mechanisms have been reported to be responsible for resistance to this antibiotic.Hypothesis or Gap Statement. Although several mechanisms of linezolid resistance have been reported in Staphylococcus haemolyticus, the prevalence and potential for horizontal transfer of resistance genes have not been fully characterized, particularly among S. haemolyticus isolates from India.Aim. To perform whole-genome sequencing (WGS) of linezolid-resistant S. haemolyticus isolates to characterize the resistance mechanisms.Methodology. WGS was performed for 16 linezolid-resistant S. haemolyticus isolates to check for the presence of cfr, optrA and poxtA genes and mutations in 23S rRNA and ribosomal proteins (L3, L4 and L22) that are possible mechanisms implicated in linezolid resistance. Sequence types were identified using MLST finder. The minimum inhibitory concentration (MIC) of linezolid was determined using the E-test method. Polymerase chain reaction (PCR) was carried out for the detection of the cfr gene.Results. The study documented three different mechanisms of linezolid resistance in S. haemolyticus. Thirteen of the 16 isolates were phenotypically resistant to linezolid, of which 12 were positive for the cfr gene. The G2603T mutation in 23S rRNA was found in the majority of the isolates (n=13). Ten isolates had the R138V mutation in L3 ribosomal protein. Twelve isolates with the cfr gene in combination with either G2603T or R138V mutations displayed extremely high MIC values. Surprisingly, three phenotypically sensitive isolates were found to be positive for the cfr gene but negative for other resistance mechanisms. Importantly, in almost half of the isolates the cfr gene was present on a plasmid. ST3 and ST1 were found to be the predominant sequence types.Conclusion. All phenotypically resistant isolates exhibited two or three linezolid resistance mechanisms. The cfr gene was found on plasmids in many isolates, demonstrating its potential for horizontal transfer to more pathogenic organisms.
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RNA Ribossômico 23S , Staphylococcus haemolyticus , Linezolida/farmacologia , Staphylococcus haemolyticus/genética , Tipagem de Sequências Multilocus , RNA Ribossômico 23S/genética , Farmacorresistência Bacteriana/genética , Antibacterianos/farmacologia , Enterococcus , Testes de Sensibilidade MicrobianaRESUMO
CONTEXT: The emergence of drug resistant pathogens pose major threat to hospitalized patients as well as to the community associated with increased mortality and morbidity. The treatment of carbapenem resistant enterobacteriaceae, one of the top WHO priority pathogen remains a global issue. Combination therapy with different classes of antibiotics have been tried with the aim to reduce toxicity, to increase the efficacy of the drugs and to reduce resistance. The in-vitro synergy methods have to be carried out to determine whether the combination of those antibiotics are synergistic, antagonistic or additive. AIMS: We have performed in-vitro synergy testing by checkerboard method for colistin -meropenem combination to determine whether the combination of the two antibiotics were synergistic or antagonistic. METHODS AND MATERIAL: All the consecutive twenty five blood isolates of Escherichia coli and twenty five blood isolates of Klebsiella pneumoniae which were showing resistance to carbapenems by either disc diffusion or vitek 2 were collected over a period of 6 months and checkerboard method was performed. STATISTICAL ANALYSIS USED: The reduction of MIC of colisin on combination with meropenem compared to MIC of colistin alone is analyzed by McNemar's chisquare test with the help of software Stata version 14 and p valueâ¯<â¯0.05 is considered as significant. RESULTS: 56% of K. pneumoniae showed synergy and 44% showed additive/indifference results. For E. coli 40% showed synergy and 60% showed additive/indifference. None of the isolates of E. coli and K. pneumoniae showed antagonism. There was more than two fold reduction in MIC of colistin (significant) on combining withmeropenem. CONCLUSIONS: The study results support the combination therapy to treat infections by multi-drug-resistant Klebsiela pneumoniae and Escherichia coli by in-vitro checkerboard testing method which inturn will be helpful for clinicians for judicious use of antimicrobials.
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Antibacterianos , Colistina , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Meropeném , Antibacterianos/farmacologia , Carbapenêmicos , Colistina/farmacologia , Farmacorresistência Bacteriana , Sinergismo Farmacológico , Humanos , Meropeném/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
Aims: Although Staphylococcus haemolyticus is considered as a part of normal skin flora, infections associated with them are increasing. Irrespective of the low virulence profile it poses a severe threat to patients with indwelling devices due to its multidrug-resistant nature. The aim of this study was to determine antibiotic resistance patterns and to detect the genes responsible in clinical isolates of S. haemolyticus. Results: All the 356 S. haemolyticus isolates were susceptible to glycopeptides. 91.3% were resistant to cefoxitin, 85.4% to erythromycin, 57.3% to co-trimoxazole, 52.8% to clindamycin, whereas only 3.7% of isolates were resistant to linezolid. Tetracycline resistance was found in 16.6% of isolates with tetK as the major genetic determinant. Most of the cefoxitin-resistant isolates carried mecA gene (99.4%), whereas dfrG gene was found only in 57.3% of co-trimoxazole-resistant isolates. Macrolides resistance was seen in 85.4% of isolates with cMLSB (constitutive macrolide, lincosamide, and streptogramin B) (42.5%) as the major phenotype with ermC and msrAB genes as the predominant genetic determinants. Among linezolid-resistant isolates all except one showed higher minimum inhibitory concentration (MIC) (>256 µg/mL) with chloramphenicol-florfenicol resistance (cfr) gene as the genetic determinant, whereas one isolate had a lower MIC (16 µg/mL) and was negative for cfr gene. Conclusion: Emerging resistance to linezolid is a cause for concern. Strategies to prevent the spread of antibiotic resistance require continuous surveillance of these multidrug-resistant strains.
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Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Staphylococcus haemolyticus/genética , Genes Bacterianos , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da PolimeraseRESUMO
Background & objectives: Although there are reports of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) across the globe, there is a lack of reliable data on hVISA in India. The present study was undertaken to determine the rate of hVISA among the methicillin-resistant Staphylococcus aureus (MRSA) isolates, and to compare the brain heart infusion agar with vancomycin 4 µg/ml (BHIV4) method with population analysis profile-area under the curve (PAP-AUC) method for the detection of hVISA and to study the distribution of mobile genetic element that carries methicillin-resistance gene SCCmec (Staphylococcal cassette chromosome mec) types among these isolates. Methods: BHIV4 and PAP-AUC methods were employed to detect hVISA among 500 clinical isolates of MRSA. SCCmec typing of these isolates was performed by multiplex polymerase chain reaction. The clinical presentation, treatment with vancomycin and outcome was documented for patients with hVISA. Results: The rate of hVISA was 12.4 per cent by PAP-AUC method. Sensitivity, specificity, PPV, NPV and kappa agreement of BHIV4 with PAP-AUC was 58.06, 93.15, 54.55, 94.01 per cent and 0.498, respectively. The isolation of hVISA was significantly (P<0.01) higher in patients admitted to intensive care units and wards than in patients attending the outpatient departments. Only 38 per cent of the patients received vancomycin as therapy. Majority of the hVISA isolates carried SCCmec type V or IV. Interpretation & conclusions: The rate of hVISA isolation in our study was 12.4 per cent. The sensitivity of the BHIV4 screening test was low, and was in moderate agreement with PAP-AUC test. SCCmec type V was the predominant type seen in half of the isolates. More studies need to be done in different parts of the country on a large number of isolates to confirm our findings.
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Proteínas de Bactérias/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Proteínas de Ligação às Penicilinas/genética , Infecções Estafilocócicas/genética , Vancomicina/uso terapêutico , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Área Sob a Curva , Meios de Cultura/química , Meios de Cultura/farmacologia , Humanos , Índia/epidemiologia , Sequências Repetitivas Dispersas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Vancomicina/efeitos adversos , Resistência a Vancomicina/genéticaRESUMO
PURPOSE: Routine surveillance of antimicrobial resistance (AMR) is an essential component of measures aimed to tackle the growing threat of resistant microbes in public health. This study presents a 1-year multicentre report on AMR in Staphylococcus species as part of Indian Council of Medical Research-AMR surveillance network. MATERIALS AND METHODS: Staphylococcus species was routinely collected in the nodal and regional centres of the network and antimicrobial susceptibility testing was performed against a panel of antimicrobials. Minimum inhibitory concentration (MIC) values of vancomycin (VAN), daptomycin, tigecycline and linezolid (LNZ) against selected methicillin-resistant Staphylococcus aureus(MRSA) isolates were determined by E-test and MIC creep, if any, was determined. Resistant genotypes were determined by polymerase chain reaction for those isolates showing phenotypic resistance. RESULTS: The prevalence of MRSA was found to be range from moderate (21%) to high (45%) among the centres with an overall prevalence of 37.3%. High prevalence of resistance was observed with commonly used antimicrobials such as ciprofloxacin and erythromycin in all the centres. Resistance to LNZ was not encountered except for a single case. Full-blown resistance to VAN in S. aureus was not observed; however, a few VAN-intermediate S. aureus isolates were documented. The most common species of coagulase negative staphylococci (CoNS) identified was Staphylococcus haemolyticus and Staphylococcus epidermidis. Resistance among CoNS was relatively higher than S. aureus. Most phenotypically resistant organisms possessed the corresponding resistance genes. CONCLUSION: There were localised differences in the prevalence of resistance between the centres. The efficacy of the anti-MRSA antimicrobials was very high; however, almost all these antimicrobials showed evidence of creeping MIC.