Use of Doxycycline in a Renal Impaired Patient with Enteroccocal Sepsis

Aim: This report highlights the use of doxycycline therapy other than the more standard regimen that includes an aminoglycoside in the management of enterococcal infection in patients with renal impairment without causing further damages to the kidney due to aminoglycoside therapy. Presentation of Case: A case of enteroccocal septicemia in a 29-year-old woman who was admitted on account of acute kidney injury secondary to pregnancy induced hypertension in the setting of pre-eclampsia. She was referred from another centre where she had emergency caesarean section done on account of severe pre-eclampsia at 36 weeks gestational age. Blood culture yielded Enterococcus species. When other antibiotic regimen failed, she was started on doxycycline. Patient had good clinical response and was discharged 7 days after commencement of doxycycline. Discussion: Enteroccoci have emerged as important agent of human disease largely because of their resistance to antimicrobial agents. They are important nosocomial pathogens capable of causing serious and potentially life-threatening infections, including sepsis. The incidence of enteroccocal infections, mainly hospital-acquired, has increased over the past 2 decades and isolates with novel mechanism of resistance to antimicrobial agents are more and more frequent. Furthermore, they have great capacity for transmitting these resistances to other species and even to other genera. Conclusion: Doxycycline is a safe and effective alternative antibiotic for the treatment of enterococcal sepsis in patients with impaired renal status.

Exploring the Therapeutic Potenital of the Leaderless Enterocins K1 and EJ97 in the Treatment of Vancomycin-Resistant Enterococcal Infection

The membrane-bound protease Eep is an important virulence factor in pathogenic enterococci. The protein is involved in stress response via the RIP pathway which is crucial for pathogenic enterococci to evade host immune attacks during infection. Eep serves also as a receptor for the bacteriocins enterocin K1 and enterocin EJ97. The bacteriocins kill Enterococcus faecium and E. faecalis, respectively, and their antibiotic resistant derivatives including vancomycin resistant enterococci (VRE). This functional duality of Eep makes these two enterocins very promising as options in the prospective treatment of enterococcal infections because wildtype enterococcal cells (with an intact Eep) are sensitive to the bacteriocins while bacteriocin-resistant-mutants (without a functional Eep) become less virulent. As a first step to explore their therapeutic potential in the treatment of systemic enterococcal infections, we investigated the compatibility of the bacteriocins with human blood, and the phenotypic changes of eep-mutants toward different stress conditions. We found that the bacteriocins were compatible with blood, as they did not cause haemolysis and that the bacteriocins retained most of their antibacterial effect when incubated in blood. The bacteriocins were autoclavable which is a crucial criterium for the development of parenteral administration. Eep-mutants, which became resistant to the bacteriocin were, as expected, less capable to withstand stress conditions such as exposure to lysozyme and desiccation. Further, their ability to chain, a trait implicated in niche adaptation as well as being necessary for genetic transfer via conjugation, was also severely affected. Together, these results indicate that the bacteriocins are promising for treatment of VRE infection.

Mechanism of Drug Resistance in Enterococci and Therapeutic Options - A Review

Enterococci exhibit an array of ways for constitutional and extrinsic resistance to primary antimicrobial agents available for clinical use. Susceptibility of these agents to β lactams, aminoglycosides or glycopeptides antibiotics or low susceptibility to combination of these agents, monomicrobial or polymicrobial nature of the infection, the involvement of heart valves or other endovascular structures affects therapy of Enterococcal infection. Vancomycin-resistant phenotypes A and B are most prevalent among medically important Enterococci isolates. Due to poor uptake of aminoglycosides, moderate level inherent resistance was reported in Enterococci. Gentamicin and Streptomycin are among the aminoglycoside antibiotics recommended for synergistic combination therapy with a cell wall acting agent. Enterococci isolates display inherent resistance to beta-lactam antibiotics due to less affinity penicillin-binding proteins, class B. Resistance to macrolides, due to erm B genotype and efflux proteins are common in Enterococci. Fluoroquinolone resistance due to genetic changes in chromosomal resistance determining regions has been observed in Enterococci isolates. Despite studies on good invitro action of Daptomycin, Linezolid and Tigecycline on Enterococci, their use may be limited due to shortage of clinical data and emergence of drug resistance. Thus optimal therapeutic option for Multidrug-resistant Enterococci infection is based on empirical observation, higher doses and combination therapies. This article reviews the antimicrobial resistance mechanism in Enterococci and available therapeutic options.

DISTRIBUTION AND ANTIBIOTICS SUSCEPTIBILITY PATTERNS OF ENTEROCOCCUS SPP. FROM A SELECTED HOSPITAL IN INDIA

Enterococci cause recurrent infections, especially among hospitalized patients. Their potential for resistance to multiple antibiotics and incumbent treatment failure constitutes a significant cause of morbidity and mortality. In this study, we aimed to determine the distribution of Enterococcus species from clinical samples and their antibiotic resistance profiles to supporting patients’ treatments based on informed-decision. We conducted a cross-sectional study at SRM Medical College Hospital, Tamil Nadu, India, from January to December 2014. Sixty Enterococcus isolates, from different clinical samples, were included in the study. The isolates were identified to species level based on sugar fermentation and biochemical reactions. The antibiotic susceptibility profile was determined using disk diffusion and agar dilution methods based on CLSI guidelines. The majority of Enterococcus isolates were recovered from urine samples (51.67%) and pus (38.33%). The predominant isolates were E. fecalis (55%) and E. fecium (33.30 %,). Others were E. avium (3.3%) and 1.7 % each for E. durans and E. raffinosus. Overall, the isolates demonstrated the highest frequency of resistance to high-level gentamicin (33.30%), and one-third (33.30%) of the isolates were multidrug-resistant. Because the majority of the drug-resistant isolates were from urine and pus samples, we concluded that suspected cases of UTIs, wound infections, and sepsis need critical evaluation for possible enterococcal infection. Clinical use of gentamicin, among other antibiotics, shall be closely monitored while treating infections.

In vitro antibacterial activity of telithromycin against Enterococcus spp. isolated from China

Background: Enterococci has resistant to a wide range of antimicrobials, and the treatment of enterococcal infection has always been an issue of concern. This study aimed to explore the new ketolides antimicrobials-telithromycin, against the planktonic cells and biofilms of enterococci. The minimum inhibitory concentration (MIC) of telithromycin was determined. The sequence types (STs) and genotypes of resistance to erythromycin in enterococci were detected. Furthermore, the effect of telithromycin against the biofilms of enterococci were investigated.Results: A total of 280 Enterococcus faecalis and 122 Enterococcus faecium isolates were collected from individual inpatients in China. Telithromycin showed excellent activity against the E. faecalis and E. faecium strains no matter sensitive or resistant to erythromycin with erm A, erm B or erm C, with the MIC50 at 2 μg/mL and 4 μg/mL, respectively. The predominant STs of E. faecalis isolates were ST16, ST30, ST179, and ST18, ST78, ST80 were the predominant STs of E. faecium isolates. Moreover, 87.1% (135/158) and 80.4% (41/51) isolates of the predominant STs carried the erm genes in E. faecalis and E. faecium isolates, respectively. The subinhibitory concentration of telithromycin (at 1/4× and 1/8× MICs) significantly inhibited the biofilm formation of 16 E. faecalis isolates. Telithromycin (at 8× MIC) indicated the removal effect on the established biofilms of 8 E. faecalis isolates, and combined with ampicillin eradicated more biofilms than telithromycin or ampicillin alone.Conclusion: Telithromycin showed an excellent activity against the planktonic cells of E. faecalis and E. faecium, and against the biofilms of E. faecalis.

Multiple Low-Reactivity Class B Penicillin-Binding Proteins Are Required for Cephalosporin Resistance in Enterococci

ABSTRACT Enterococcus faecalis and Enterococcus faecium are commensals of the gastrointestinal tract of most terrestrial organisms, including humans, and are major causes of health care-associated infections. Such infections are difficult or impossible to treat, as the enterococcal strains responsible are often resistant to multiple antibiotics. One intrinsic resistance trait that is conserved among E. faecalis and E. faecium is cephalosporin resistance, and prior exposure to cephalosporins is one of the most well-known risk factors for acquisition of an enterococcal infection. Cephalosporins inhibit peptidoglycan biosynthesis by acylating the active-site serine of penicillin-binding proteins (PBPs) to prevent the PBPs from catalyzing cross-linking during peptidoglycan synthesis. For decades, a specific PBP (known as Pbp4 or Pbp5) that exhibits low reactivity toward cephalosporins has been thought to be the primary PBP required for cephalosporin resistance. We analyzed other PBPs and report that in both E. faecalis and E. faecium, a second PBP, PbpA(2b), is also required for resistance; notably, the cephalosporin ceftriaxone exhibits a lethal effect on the ΔpbpA mutant. Strikingly, PbpA(2b) exhibits low intrinsic reactivity with cephalosporins in vivo and in vitro. Unlike the Δpbp5 mutant, the ΔpbpA mutant exhibits a variety of phenotypic defects in growth kinetics, cell wall integrity, and cellular morphology, indicating that PbpA(2b) and Pbp5(4) are not functionally redundant and that PbpA(2b) plays a more central role in peptidoglycan synthesis. Collectively, our results shift the current understanding of enterococcal cephalosporin resistance and suggest a model in which PbpA(2b) and Pbp5(4) cooperate to coordinately mediate peptidoglycan cross-linking in the presence of cephalosporins.

Study of vancomycin and high-level aminoglycoside-resistant Enterococcus species and evaluation of a rapid spot test for enterococci from Central Referral Hospital, Sikkim, India

BACKGROUND: Enterococcus is an important pathogen, and with its emergence of resistance to multiple antimicrobials, the management of infection is becoming increasingly difficult. AIM: The aim of the study is to determine the prevalence, antibiotic resistance, and risk factors associated with enterococcal infection or colonization. MATERIALS AND METHODS: In this prospective study, samples from inpatients were screened for resistant enterococci. Antibiotic susceptibility testing was performed using the disc diffusion method and minimum inhibitory concentration by the agar dilution method. A modification of a test tube method of sodium chloride-esculin hydrolysis to a spot test was evaluated for its rapidity and reliability in the presumptive diagnosis of enterococci. STATISTICAL ANALYSIS USED: Fisher's exact test was used for continuous (Student's t-test) and categorical variables. Multivariate analysis was performed with logistic regression using IBM SPSS 20.0 software (Armonk, NY, USA). RESULTS: Enterococcus species were isolated from 182 samples: Enterococcus faecalis (68.7%), Enterococcus faecium (20.9%), Enterococcus gallinarum (6%), and Enterococcus durans (4.4%). Maximum resistance was to ciprofloxacin (59.3%) and least to linezolid (0.5%). The isolation rate of vancomycin-resistant enterococci (VRE) was 13.7%; 30.2% and 20.9% were of high-level gentamicin and streptomycin, respectively. All 182 Enterococcus species gave positive results within 30–60 min by the rapid spot test. CONCLUSIONS: Overall, high-level aminoglycoside resistance (HLAR) was observed more than glycopeptide resistance. Surveillance strategies need to be upgraded and implemented in order to prevent the emergence and further spread of not only VRE but also HLAR enterococci in the hospital. The spot test gave reliable and rapid results in presumptive identification of enterococci.

Cultivation of oyster mushroom (Pleurotus sp) using different substrates and evaluate their potentials of antibacterial and phytochemicals

Mushroom is a variety of gilled fungi belongs to the class Basidiomycetes. It grows on tropical and northern temperate regions mainly in a moist condition. Mushroom act as a reservoir of nutrients. Edible mushroom plays a vital role in maintaining human health. The most commonly used edible mushroom is Pleurotus (oyster). It is rich in Protein, fibre, minerals and vitamins. It has a variety of fascinating properties like anti-inflammatory, anticancer, antiaging, analgesic and immune modulator property. The present study investigates the various phytochemicals and antibacterial potentials from the methanol, ethanol and aqueous extracts of fruit body mushroom. The cultivation of mushroom using different substrates such as paddy straw and corn straw. The mushroom extracts were subjected to qualitative phytochemical screening using standard methods. The crude extracts contain Alkaloids, Steroids, Flavonoids, Saponins, Phenols, Tannins, Proteins, Amino acids, Carbohydrates, Reducing sugar. The results indicated that the ethanolic extract had shown significant antibacterial activity against the test organisms. Enterococcal infection is a common infection prevailing nowadays. This study suggests that mushroom possess antibacterial potential against enterococcal species. So, intake of mushroom acts as a medicine for enterococcal infections.

Efficacy of Empiric Treatment of Urinary Tract Infections in Neonates and Young Infants

Background. The antibiotic resistance patterns of young infants with urinary tract infections (UTIs) have evolved over the past 2 decades. Whether current empiric antibiotic regimens are sufficient in this age group is unknown. Methods. A retrospective review of patients aged 0 to 60 days admitted with a UTI discharge diagnosis. Results. Overall susceptibility to empiric antibiotics was 87%. Antibiotic resistance and length of stay were highest among those who were afebrile, those admitted to the intensive care unit, and those with culture diagnosis of enterococcal infection. The sensitivity and specificity of ultrasound as a screening tool for genitourinary anomaly was 70% and 40%, respectively, with a positive predictive value of 31.8%. Conclusions. Empiric antibiotic regimens cover a high percentage of UTIs in infants. However, high rates of resistance and prolonged length of stay in patients with enterococcal infection highlight the need for continued surveillance of such patients in this age group.