rifampin and Flavobacteriaceae-Infections

Elizabethkingia meningoseptica, a Gram-negative pathogen once deemed clinically insignificant, tends to cause infections among low-birth-weight infants and immunocompromised patients. Previously, vancomycin was reported to cure several patients with bacteraemia caused by E. meningoseptica. Nevertheless, some laboratory investigations also showed considerable discordance between in vitro vancomycin susceptibility results obtained by the disk diffusion and broth microdilution methods against clinical E. meningoseptica isolates as determined using the criteria for staphylococci recommended by the Clinical and Laboratory Standards Institute (CLSI). In this review, the PubMed database (1960-2017) was searched for studies that reported mainly cases with E. meningoseptica bacteraemia or meningitis treated with vancomycin alone or with regimens that included vancomycin. In addition, the in vitro synergy between vancomycin and other agents against isolates of E. meningoseptica was reviewed. Elizabethkingia meningoseptica bacteraemia appears not to universally respond to intravenous (i.v.) vancomycin-only therapy, especially in patients who require haemodialysis. If i.v. vancomycin is the favoured therapy against E. meningoseptica meningitis, the addition of ciprofloxacin, linezolid or rifampicin might be an option to effectively treat this difficult-to-treat infection. Further clinical studies are needed to determine the clinical efficacy of these combination regimens for the treatment of E. meningoseptica meningitis.

Topics: Anti-Bacterial Agents; Bacteremia; Ciprofloxacin; Disk Diffusion Antimicrobial Tests; Drug Synergism; Drug Therapy, Combination; Flavobacteriaceae; Flavobacteriaceae Infections; Humans; Immunocompromised Host; Infant, Low Birth Weight; Infant, Newborn; Linezolid; Meningitis, Bacterial; Rifampin; Treatment Outcome; Vancomycin

Elizabethkingia meningoseptica (E. meningoseptica ) are Gram-negative bacteria commonly associated with nosocomial infections in neonates. This is a case study of E. meningoseptica, presented as meningitis and sepsis in a term baby. The female infant was born by vaginal delivery at 37 weeks gestational age. The case was peculiar because the baby was neither premature nor immuno-compromised, which are known risk factors for E. meningoseptica infection. The onset began on the second day of the neonate's life. On day 3, peripheral blood culture and cerebrospinal fluid findings isolated a gram-negative bacteria identified as E. meningoseptica. The first-line antibiotics therapy was changed to ciprofloxacin, vancomycin, and rifampicin, based on the laboratory determination of antimicrobial sensitivity. The patient's clinical condition improved, although post hemorrhagic ventricular dilatation was revealed by imaging studies. Clinicians should possess proper awareness of the antibiotic sensitivity of E. meningoseptica, as it is important in preventing high rates of morbidity and mortality.

Topics: Anti-Bacterial Agents; Ciprofloxacin; Drug Resistance, Bacterial; Drug Therapy, Combination; Female; Flavobacteriaceae; Flavobacteriaceae Infections; Humans; Infant, Newborn; Meningitis, Bacterial; Rifampin; Saudi Arabia; Sepsis; Treatment Outcome; Vancomycin

Topics: Aged; Amikacin; Anti-Bacterial Agents; Chryseobacterium; Drug Therapy, Combination; Flavobacteriaceae Infections; Humans; Male; Meropenem; Rifampin; Shock, Septic; Tigecycline; Trimethoprim, Sulfamethoxazole Drug Combination

Elizabethkingia genus is emerging in hospitals and resistant to multiple antibiotics. The intrinsic imipenem resistance of Elizabethkingia genus is related to two chromosome-encoded metallo-beta-lactamases (MBLs), BlaB and GOB. This study was aimed to investigate the in vitro activity of imipenem, vancomycin, and rifampicin in clinical Elizabethkingia species. The distribution and heterogeneity of MBLs responsible for imipenem resistance were also evaluated. A total of 167 Elizabethkingia isolates from different patients were collected, including E. anophelis (142), E. meningoseptica (11), and E. miricola (14). All isolates were evaluated by the broth microdilution assay, ethylenediaminetetraacetic acid (EDTA) combination disk test, and EDTA-based microdilution test. The characteristics of BlaB and GOB were evaluated in phylogenetic analysis and heterologous expression experiments. Most of the isolates were susceptible to rifampin (94%), whereas none of the isolates were susceptible to imipenem. Vancomycin showed intermediate effectiveness. EDTA could reduce 4 folds or more minimum inhibitory concentrations (MICs) of imipenem in 105 isolates (62.9%). Of the isolates, the amino acid sequences of BlaB and GOB were divided into 22 and 25 different types, respectively. Phylogenetic analysis showed BlaB and GOB are species-specific proteins. Furthermore, GOB and BlaB from E. anophelis showed higher imipenem hydrolysis efficiency than those from the other two species. Rifampicin remained the most active agent in the current study. The mechanism of Elizabethkingia resistance to imipenem primarily stemmed from MBLs but other mechanisms could also exist, which requires further investigation.

Topics: Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Drug Resistance, Bacterial; Edetic Acid; Flavobacteriaceae; Flavobacteriaceae Infections; Humans; Imipenem; Microbial Sensitivity Tests; Phylogeny; Rifampin; Species Specificity; Vancomycin

Flavobacterium psychrophilum is the etiologic agent of bacterial coldwater disease in salmonids. Earlier research showed that a rifampicin-passaged strain of F. psychrophilum (CSF 259-93B.17) caused no disease in rainbow trout (Oncorhynchus mykiss, Walbaum) while inducing a protective immune response against challenge with the virulent CSF 259-93 strain. We hypothesized that rifampicin passage leads to an accumulation of genomic mutations that, by chance, reduce virulence. To assess the pattern of phenotypic and genotypic changes associated with passage, we examined proteomic, LPS and single-nucleotide polymorphism (SNP) differences for two F. psychrophilum strains (CSF 259-93 and THC 02-90) that were passaged with and without rifampicin selection.. Rifampicin resistance was conveyed by expected mutations in rpoB, although affecting different DNA bases depending on the strain. One rifampicin-passaged CSF 259-93 strain (CR) was attenuated (4 % mortality) in challenged fish, but only accumulated eight nonsynonymous SNPs compared to the parent strain. A CSF 259-93 strain passaged without rifampicin (CN) accumulated five nonsynonymous SNPs and was partially attenuated (28 % mortality) compared to the parent strain (54.5 % mortality). In contrast, there were no significant change in fish mortalities among THC 02-90 wild-type and passaged strains, despite numerous SNPs accumulated during passage with (n = 174) and without rifampicin (n = 126). While only three missense SNPs were associated with attenuation, a Ser492Phe rpoB mutation in the CR strain may contribute to further attenuation. All strains except CR retained a gliding motility phenotype. Few proteomic differences were observed by 2D SDS-PAGE and there were no apparent changes in LPS between strains. Comparative methylome analysis of two strains (CR and TR) identified no shared methylation motifs for these two strains.. Multiple genomic changes arose during passage experiments with rifampicin selection pressure. Consistent with our hypothesis, unique strain-specific mutations were detected for the fully attenuated (CR), partially attenuated (CN) and another fully attenuated strain (B17).

Topics: Animals; Anti-Bacterial Agents; DNA-Directed RNA Polymerases; Drug Resistance, Bacterial; Fish Diseases; Flavobacteriaceae Infections; Flavobacterium; Lipopolysaccharides; Molecular Sequence Data; Oncorhynchus mykiss; Polymorphism, Single Nucleotide; Proteome; Rifampin; Selection, Genetic; Sequence Analysis, DNA; Serial Passage; Survival Analysis; Virulence

We report a nosocomial outbreak of urinary tract infection caused by Myroides odoratimimus, previously called Flavobacterium odoratum, in the urology unit of a Tunisian hospital. From May to November 2010, seven isolates of M. odoratimimus were recovered from urine. Pulsed-field gel electrophoresis clearly differentiated these isolates into two possibly related clones from two different periods. All patients but one had urinary calculi and underwent endourological surgery. All Myroides isolates were resistant to all antibiotics tested. Three patients were successfully treated with ciprofloxacin and rifampicin. Clinicians should be aware that M. odoratimimus may induce serious and prolonged nosocomial outbreaks of urinary tract infections.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Ciprofloxacin; Cluster Analysis; Cross Infection; Disease Outbreaks; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Flavobacteriaceae; Flavobacteriaceae Infections; Humans; Male; Middle Aged; Molecular Typing; Rifampin; Tunisia; Urinary Tract Infections; Urine

Flavobacterium psychrophilum is the aetiologic agent of bacterial coldwater disease and rainbow trout fry syndrome. In this study, we compared a wild-type strain (CSF 259-93) with a rifampicin-resistant strain and virulence-attenuated strain of F. psychrophilum (CSF 259-93B.17). The attenuated strain harboured a mutation in the rpoB gene consistent with resistance to rifampicin. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry demonstrated an altered proteome with eight proteins characteristic for the parent strain and six that were unique to the attenuated strain. Immunoblotting with a diagnostic monoclonal antibody (FL-43) identified a putative antigen (FP1493) that was subsequently cloned, expressed as a recombinant protein and confirmed as recognized by FL-43. 2D-PAGE, immunoblotting with rainbow trout, Oncorhynchus mykiss (Walbaum), convalescent antisera and mass spectrometry of bacterial whole-cell lysates revealed several uniquely expressed immunoreactive proteins including FP1493. An FP1493 recombinant subunit vaccine was tested, but did not provide protection against challenge with the CSF259-93 strain. While the exact mechanism responsible for altered protein synthesis and attenuation of CSF 259-93B.17 is still unknown, the differentially expressed immunoreactive proteins are a valuable resource to develop subunit vaccines and to identify proteins that are potentially involved in disease.

Topics: Animals; Antibodies, Bacterial; Bacterial Proteins; Bacterial Vaccines; Drug Resistance, Bacterial; Fish Diseases; Flavobacteriaceae Infections; Flavobacterium; Gene Expression Regulation, Bacterial; Immunization; Proteome; Rifampin; Virulence

Topics: Anti-Bacterial Agents; Bacteremia; Blood; Cerebrospinal Fluid; Female; Flavobacteriaceae; Flavobacteriaceae Infections; Humans; Meningitis; Microscopy; Middle Aged; Rifampin; Stem Cell Transplantation; Transplantation; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination

Elizabethkingia meningoseptica is a rare but well-recognised cause of neonatal meningitis. Reported outbreaks have involved very few cases. We describe the management and outcome of a relatively large outbreak of E.meningoseptica neonatal meningitis. From August 2002 to December 2003, eight cases of meningitis caused by E. meningoseptica occurred among babies admitted to the neonatal ward of Jawarhlal Nehru hospital, Mauritius. In all cases, the organism was isolated from the cerebrospinal fluid. Infection control measures were re-emphasized after each case and environmental swabs were cultured on several occasions. . The affected babies were aged 6 to 20 days (mean age of 10 days). Seven of the babies weighed < 2,500 g. All CSF isolates had the same antibiotic susceptibility pattern. Apart from one baby who died shortly after admission, all cases responded to treatment with intravenous piperacillin and oral rifampicin for three weeks. Hydrocephalus developed in two babies and was subsequently fatal in one case. At follow-up of the other cases, one baby had severe neurological sequelae but a full recovery was observed in the other four cases. The source of the outbreak could not be established conclusively. . The outcome was better than what has been reported in the medical literature. Prompt identification of the causative organism and initiation of appropriate antimicrobial therapy is essential. The combination of piperacillin and rifampicin should be considered an option for the treatment of E. meningoseptica neonatal meningitis if supported by properly performed antibiotic susceptibility test results. 

Topics: Anti-Bacterial Agents; Cerebrospinal Fluid; Disease Outbreaks; Environmental Microbiology; Female; Flavobacteriaceae; Flavobacteriaceae Infections; Humans; Hydrocephalus; Infant, Newborn; Male; Mauritius; Meningitis, Bacterial; Microbial Sensitivity Tests; Piperacillin; Rifampin; Treatment Outcome

Previous studies have demonstrated that passage of pathogenic bacteria on increasing concentrations of the antibiotic rifampicin leads to the attenuation of virulence and these resistant strains may serve as live attenuated vaccines. Two rifampicin resistant strains of Flavobacterium psychrophilum, 259-93A.16 and 259-93B.17, were generated by passage on TYES plates containing increasing concentrations of rifampicin. Electrophoretic analysis of whole-cell lysates prepared from the parent and resistant strains identified five differentially expressed proteins between the 259-93B.17 strain and parent strain, while there were no differences identified between the 259-93A.16 and parent strain. The LPS banding patterns were identical between all three strains. Bacterial challenges of rainbow trout (Oncorhynchus mykiss Walbaum) with the resistant strains demonstrated that the 259-93B.17 strain was highly attenuated and the 259-93A.16 strain was modestly attenuated at the challenge doses tested. Immunization of rainbow trout with the live attenuated 259-93B.17 strain by intraperitoneal injection resulted in significant protection against challenge with the virulent parent F. psychrophilum strain at 8 and 15 weeks post-immunization and fish exhibited elevated specific antibody titers. Importantly, immersion delivery of the 259-93B.17 strain stimulated protective immune responses in fish at 10 weeks post-immunization. The results demonstrate that the rifampicin resistant 259-93B.17 strain may serve as an effective live attenuated vaccine for the prevention of F. psychrophilum infections.

Topics: Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Bacterial Vaccines; Drug Resistance, Bacterial; Fish Diseases; Flavobacteriaceae Infections; Flavobacterium; Immunization; Oncorhynchus mykiss; Rifampin; Vaccines, Attenuated; Virulence