Piscibacillus halophilus sp. nov., a moderately halophilic bacterium from a hypersaline Iranian lake.

A Gram-positive, moderately halophilic bacterium, designated strain HS224(T), was isolated from the hypersaline lake Howz-Soltan in Iran. Cells of strain HS224(T) were rod-shaped, motile and produced oval endospores. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HS224(T) was affiliated to the genus Piscibacillus, exhibiting 98.5 % sequence similarity to the type strain of Piscibacillus salipiscarius. Strain HS224(T) was also related closely to the type strains of Aquisalibacillus elongatus (98.0 % 16S rRNA gene sequence similarity), Filobacillus milosensis (97.9 %) and Tenuibacillus multivorans (97.0 %). Strain HS224(T) was able to grow at NaCl concentrations of 1-20 % (w/v), with optimum growth occurring at 10 % (w/v) NaCl. The optimum temperature and pH for growth were 35 degrees C and pH 7.5. Major polar lipids were phosphatidylglycerol and diphosphatidylglycerol, the isoprenoid quinone was MK-7 and the peptidoglycan type was A1gamma, with meso-diaminopimelic acid as the diagnostic diamino acid; these characteristics were shared with P. salipiscarius. The major cellular fatty acids of strain HS224(T) were anteiso-C(15 : 0), iso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0). The G+C content of the DNA was 37.5 mol%. The level of DNA-DNA relatedness between strain HS224(T) and P. salipiscarius JCM 13188(T) was 30.8 %. It is evident from the genotypic, chemotaxonomic and phenotypic data presented that strain HS224(T) represents a novel species of the genus Piscibacillus, for which the name Piscibacillus halophilus sp. nov. is proposed. The type strain is HS224(T) (=CCM 7596(T)=DSM 21633(T)=JCM 15721(T)=LMG 24786(T)).

Bacillus persepolensis sp. nov., a moderately halophilic bacterium from a hypersaline lake.

A Gram-positive, moderately halophilic, endospore-forming bacterium, designated strain HS136T, was isolated from the hypersaline lake Howz-Soltan in Iran. Cells were motile rods, producing ellipsoidal endospores at a central-subterminal position in non-swollen sporangia. Strain HS136T, a strictly aerobic bacterium, grew between pH 7.0 and 10.0 (optimal growth at pH 8.0-8.5), between 25 and 45 degrees C (optimal growth at 40 degrees C) and at salinities of 5-20% (w/v) NaCl, growing optimally at 10% (w/v) NaCl. On the basis of 16S rRNA gene sequence analysis, strain HS136T was shown to belong to the genus Bacillus within the phylum Firmicutes and showed closest phylogenetic similarity to Bacillus salarius BH169T (95.2%) and Bacillus qingdaonensis CM1T (94.5%). The DNA G+C content of this new isolate was 37.1 mol%. The major cellular fatty acids of strain HS136T were iso-C15:0, anteiso-C15:0 and anteiso-C17:0, and its polar lipid pattern consisted of phosphatidylglycerol and diphosphatidylglycerol. The isoprenoid quinone was MK-7. The peptidoglycan type is A1gamma, with meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of polyphasic evidence from this study, Bacillus persepolensis sp. nov. is proposed, with strain HS136T (=CCM 7595T=DSM 21632T=JCM 15720T=LMG 25222T) as the type strain.

Thalassobacillus cyri sp. nov., a moderately halophilic Gram-positive bacterium from a hypersaline lake.

A Gram-positive, moderately halophilic bacterium, designated strain HS286(T), was isolated from water of the hypersaline Lake Howz-Soltan in Iran. Cells were strictly aerobic, rod-shaped, motile and able to produce ellipsoidal endospores at a central-subterminal position in swollen sporangia. Isolate HS286(T) grew in a complex medium supplemented with 1-15 % (w/v) NaCl, with optimum growth at 8.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain HS286(T) was closely related to Thalassobacillus devorans G-19.1(T) (99.4 % gene sequence similarity). The other closest species were Halobacillus yeomjeoni MSS-402(T) (96.9 %) and other species of the genus Halobacillus (with 96.7-93.5 % similarity). Strain HS286(T) had cell-wall peptidoglycan based on meso-diaminopimelic acid and MK-7 as the respiratory isoprenoid quinone. The major fatty acids were anteiso-C(15 : 0) (43.8 %), iso-C(16 : 0) (21.4 %), iso-C(14 : 0) (9.4 %), anteiso-C(17 : 0) (8.7 %) and iso-C(15 : 0) (7.0 %) and the polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, two phospholipids and a glycolipid. The DNA G+C content was 43.0 mol%. All of these features confirmed the placement of isolate HS286(T) within the genus Thalassobacillus. However DNA-DNA hybridization between strain HS286(T) and the only recognized species of the genus Thalassobacillus, T. devorans G-19.1(T), was 27.3 %, showing unequivocally that the novel isolate constituted a new genospecies. Strain HS286(T) could be clearly differentiated from T. devorans and other phylogenetic neighbours on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore, strain HS286(T) constitutes a novel species, for which the name Thalassobacillus cyri sp. nov. is proposed. The type strain is HS286(T) (=CCM 7597(T)=JCM 15722(T)).

Screening and isolation of halophilic bacteria producing extracellular hydrolyses from Howz Soltan Lake, Iran.

Screening of bacteria from different areas of Howz Soltan playa, a hypersaline lake in the central desert zone of Iran, led to the isolation of 231 moderately halophilic bacteria, which were able to grow optimally in media with 5-15% of salt, and 49 extremely halophilic microorganisms that required 20-25% of salt for optimal growth. These isolates produced a great variety of extracellular hydrolytic enzymes. A total of 195, 177, 100, 95, 92, 68, 65, 33, and 28 strains produced lipases, amylases, proteases, inulinases, xylanases, cellulases, pullulanases, DNases, and pectinases, respectively. In comparison with gram-negative bacteria, the gram-positive halophilic rods, showed more hydrolytic activities. Several combined activities were showed by some of these isolates. One strain presented 9 hydrolytic activities, 4 strains presented 8 hydrolytic activities, 10 strains presented 7 hydrolytic activities and 29 strains presented 6 hydrolytic activities. No halophilic isolate without hydrolytic activity has been found in this study. According to their phenotypic characteristics and comparative partial 16S rRNA sequence analysis, the halophilic strains were identified as members of the genera: Salicola, Halovibrio, Halomonas, Oceanobacillus, Thalassobacillus, Halobacillus, Virgibacillus, Gracilibacillus, Salinicoccus, and Piscibacillus. Most lipase and DNase producers were members of the genera Gracilibacillus and Halomonas, respectively, whereas most of the isolates able to produce hydrolytic enzymes such as amylase, protease, cellulose (CMCase) and inulinase, belonged to gram-positive genera, like Gracilibacillus, Thalassobacillus, Virgibacillus, and Halobacillus.

Isolation of the first metallo - â - lactamase producing Klebsiella pneumoniae in Lebanon

Introduction. A 58 year-old man was admitted to theSaint Joseph Hospital-Raymond and Aida Najjar polyclinicin Beirut on July 17, 2007 to undergo surgery for a moderatelydifferentiated colonic adenocarcinoma (T3N0). Followingseveral discharges and re-admissions, an extendedspectrum beta-lactamase (ESBL) producing Escherichia colisusceptible to imipenem was isolated. The patient was puton imipenem and metronidazole. Three weeks later, imipenem(IMP) resistant Klebsiella pneumoniae was isolated.Methods and results. The antimicrobial susceptibilityprofile of the imipenem-resistant Klebsiella pneumoniaestrain and related minimum inhibitory concentrations ofantibiotics were determined. Hydrolysis of IMP was evaluatedand production of metallo-â-lactamase (MBL) was detectedby a double disk-synergy test, ethylene diamine tetraaceticacid (EDTA) inhibited the imipenemase activity,whereas clavulanate and tazobactam did not, this suggestingthe production of a metallo-â-lactamase. Isoelectricfocusing analysis was performed and indicated the presenceof a cefotaximase (blaCTX-M-15). Polymerase chain reaction(PCR) was used and detected the presence of blaIMP-1and blaCTX-M genes.Conclusions. During the last decade, many hospitaloutbreaks caused by ESBL-producing Enterobacteriaceaespp. have been reported in Lebanon. To our knowledge, thisis the first report of a clinical isolate of K. pneumoniae producingan MBL in Lebanon (AU)

Introducción. El 17 de julio de 2007 un varón de58 años de edad fue ingresado en Hospital de Saint Joseph-Raymond and Aida Najjar Polyclinic de Beirut parasometerse a una intervención quirúrgica por un adenocarcinomamoderadamente diferenciado de colon (T3N0).Después de varias altas y rehospitalizaciones se aisló unaEscherichia coli productora de betalactamasa de espectroextendido y sensible al imipenem (IMP). El paciente fuetratado con imipenem y metronidazol. Una semana mástarde se efectuó un cultivo en el que se determinó Klebsiellapneumoniae resistente al imipenem.Métodos y resultados. Se determinó el perfil de sensibilidadantimicrobiana de la cepa de Klebsiella pneumoniaeresistente al imipenem y las concentracionesmínimas inhibitorias de los antibióticos. Se evaluó la hidrólisisdel IMP y se detectó la producción de metalo-betalactamasa(MBL) mediante el ensayo de sinergia condoble disco. El ácido etilendiaminotetraacético (EDTA)inhibió la actividad de la imipenemasa, mientras queclavulanato y tazobactam no, lo que indica la producciónde metalo-betalactamasa. Se efectuó un análisis porenfoque isoeléctrico que indicó la presencia de cefotaximasa(blaCTX-M-15). Para detectar la presencia de losgenes blaIMP-1 y blaCTX-M se empleó la reacción encadena de polimerasa (polymerase chain reaction [PCR]).Conclusiones. Durante la última década se han documentadomuchos brotes hospitalarios causados por especiesde enterobacterias productoras de ESBL en Líbano.A nuestro entender éste es el primer informe de unacepa clínica de K. pneumoniae productora de MBL en Líbano. (AU)

Isolation of the first metallo-beta-lactamase producing Klebsiella pneumoniae in Lebanon.

INTRODUCTION: A 58 year-old man was admitted to the Saint Joseph Hospital-Raymond and Aida Najjar polyclinic in Beirut on July 17, 2007 to undergo surgery for a moderately differentiated colonic adenocarcinoma (T3N0). Following several discharges and re-admissions, an extended spectrum beta-lactamase (ESBL) producing Escherichia coli susceptible to imipenem was isolated. The patient was put on imipenem and metronidazole. Three weeks later, imipenem (IMP) resistant Klebsiella pneumoniae was isolated. METHODS AND RESULTS: The antimicrobial susceptibility profile of the imipenem-resistant Klebsiella pneumoniae strain and related minimum inhibitory concentrations of antibiotics were determined. Hydrolysis of IMP was evaluated and production of metallo-beta-lactamase (MBL) was detected by a double disk-synergy test, ethylene diamine tetraacetic acid (EDTA) inhibited the imipenemase activity, whereas clavulanate and tazobactam did not, this suggesting the production of a metallo-beta-lactamase. Isoelectric focusing analysis was performed and indicated the presence of a cefotaximase (blaCTX-M-15). Polymerase chain reaction (PCR) was used and detected the presence of blaIMP-1 and blaCTX-M genes. CONCLUSIONS: During the last decade, many hospital outbreaks caused by ESBL-producing Enterobacteriaceae spp. have been reported in Lebanon. To our knowledge, this is the first report of a clinical isolate of K. pneumoniae producing an MBL in Lebanon.

[Lactobacillus rhamnosus septicemia in a diabetic patient associated with probiotic use: a case report]. / Septicémie à Lactobacillus rhamnosus chez une patiente diabétique prenant un traitement probiotique.

BACKGROUND: probiotic agents are increasingly used as over the counter drugs for the treatment of a variety of inflammatory and infectious conditions. The rationale of their use seems to restore a friendly bacterial flora in the gut. Complications of probiotic use, although rarely reported, can occur. OBSERVATION: we describe the case of a 54-year-old diabetic woman, who developed Lactobacillus rhamnosus septicemia while she was using probiotic oral treatment. Lactobacillus is a major component of probiotic agents. Her infection resolved after amoxicilline administration. DISCUSSION: this case highlights the complication of probiotic use, and perhaps the patient's predispositions to develop such complications.

Resistance profile and cross-resistance of HIV-1 among patients failing a non-nucleoside reverse transcriptase inhibitor-containing regimen.

The objectives were to determine the resistance profile and the rate of cross-resistance in HIV-1 infected patients failing an efavirenz or a nevirapine or a nevirapine then efavirenz containing regimens, and to investigate if zidovudine and more generally thymidine analog nucleosides lead to a particular genotypic pattern in nevirapine failing patients. A study was conducted in 104 patients with virological rebound to a non-nucleoside reverse transcriptase inhibitors (NNRTI) regimen (efavirenz n = 39, nevirapine n = 46 and nevirapine then efavirenz n = 19). Genotypic resistance testing was carried out of detectable plasma HIV-1 RNA (> 200 copies/ml). Among the 104 patients studied, only two patients failed to respond to the nevirapine regimen without selection of a NNRTI resistance mutation. All patients failing an efavirenz regimen harboured mutations conferring cross-resistance to nevirapine (K103N, Y188L, G190S). Among patients failing the nevirapine regimen and presenting with NNRTI mutations, 35 (80%) harboured mutations conferring cross-resistance to efavirenz (K101E, K103N, Y188L) and 9 (20%) harboured mutations conferring resistance to nevirapine alone (V106A and Y181C). In patients failing nevirapine then efavirenz therapy, all NNRTI resistance profile led to cross-resistance to all available NNRTIs. Among patients receiving nevirapine, the selection of mutations associated with a cross-resistance to efavirenz was more frequent statistically when a thymidine nucleoside analog (zidovudine or stavudine) was used in the regimen (P = 0.02). In conclusion, 100% of patients developed cross-resistance to nevirapine and efavirenz after treatment by efavirenz and 80% after treatment by nevirapine. The use of a thymidine analog concomitantly with nevirapine leads to the preferential selection of cross-resistance NNRTI mutations.