Genetic Environment Surrounding bla OXA-55-like in Clinical Isolates of Shewanella algae Clade and Enhanced Expression of bla OXA-55-like in a Carbapenem-Resistant Isolate

Shewanella spp., which are known to carry chromosomally located bla OXA genes, have mainly been isolated from marine environments; however, they can also cause infections in humans. In this study, we compared the molecular characteristics of clinical isolates of Shewanella spp. with those originating from environmental sources. All 10 clinical isolates were genetically identified as members of the Shewanella algae clade ( S. algae , S. chilikensis , and S. carassii ); however, all but one of the 13 environmental isolates were identified as Shewanella species members outside the S. algae clade.

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Contaminated Handwashing Sinks as the Source of a Clonal Outbreak of KPC-2-Producing Klebsiella oxytoca on a Hematology Ward

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04306-14 ◽

2014 ◽

Vol 59 (1) ◽

pp. 714-716 ◽

Cited By ~ 61

Author(s):

Eva Leitner ◽

Gernot Zarfel ◽

Josefa Luxner ◽

Kathrin Herzog ◽

Shiva Pekard-Amenitsch ◽

...

Keyword(s):

Resistance Genes ◽

Genetic Relatedness ◽

Klebsiella Oxytoca ◽

Klebsiella Pneumonia ◽

Environmental Isolates ◽

Content Type ◽

Carbapenem Resistant

ABSTRACTWe investigated sinks as possible sources of a prolongedKlebsiella pneumoniacarbapenemase (KPC)-producingKlebsiella oxytocaoutbreak. Seven carbapenem-resistantK. oxytocaisolates were identified in sink drains in 4 patient rooms and in the medication room. Investigations for resistance genes and genetic relatedness of patient and environmental isolates revealed that all the isolates harbored theblaKPC-2andblaTEM-1genes and were genetically indistinguishable. We describe here a clonal outbreak caused by KPC-2-producingK. oxytoca, and handwashing sinks were a possible reservoir.

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Complete Genome Sequence of Pseudomonas aeruginosa K34-7, a Carbapenem-Resistant Isolate of the High-Risk Sequence Type 233

Microbiology Resource Announcements ◽

10.1128/mra.00886-18 ◽

2018 ◽

Vol 7 (4) ◽

Cited By ~ 2

Author(s):

George Taiaroa ◽

Ørjan Samuelsen ◽

Tom Kristensen ◽

Ole Andreas Løchen Økstad ◽

Adam Heikal

Keyword(s):

Pseudomonas Aeruginosa ◽

High Risk ◽

Genome Sequence ◽

Complete Genome Sequence ◽

Complete Genome ◽

Sequence Type ◽

Resistant Isolate ◽

Content Type ◽

Carbapenem Resistant ◽

New Antibiotics

Carbapenem-resistant Pseudomonas aeruginosa is defined as a “critical” priority pathogen for the development of new antibiotics. Here we report the complete genome sequence of an extensively drug-resistant, Verona integron-encoded metallo-β-lactamase-expressing isolate belonging to the high-risk sequence type 233.

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High-Level Carbapenem Resistance in OXA-232-Producing Raoultella ornithinolytica Triggered by Ertapenem Therapy

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01335-19 ◽

2019 ◽

Vol 64 (1) ◽

Cited By ~ 2

Author(s):

Alina Iovleva ◽

Roberta T. Mettus ◽

Christi L. McElheny ◽

Marissa P. Griffith ◽

Mustapha M. Mustapha ◽

...

Keyword(s):

Rapid Development ◽

Carbapenem Resistance ◽

Resistant Isolate ◽

Clinical Microbiology Laboratory ◽

Loss Of Function ◽

Content Type ◽

Carbapenem Resistant ◽

Class D ◽

Fold Reduction ◽

High Level

ABSTRACT OXA-232 is an OXA-48-group class D β-lactamase that hydrolyzes expanded-spectrum cephalosporins and carbapenems at low levels. Clinical strains producing OXA-232 are sometimes susceptible to carbapenems, making it difficult to identify them in the clinical microbiology laboratory. We describe the development of carbapenem resistance in sequential clinical isolates of Raoultella ornithinolytica carrying blaOXA-232 in a hospitalized patient, where the ertapenem MIC increased from 0.5 μg/ml to 512 μg/ml and the meropenem MIC increased from 0.125 μg/ml to 32 μg/ml during the course of ertapenem therapy. Whole-genome sequencing (WGS) analysis identified loss-of-function mutations in ompC and ompF in carbapenem-resistant isolates that were not present in the initial carbapenem-susceptible isolate. Complementation of a carbapenem-resistant isolate with an intact ompF gene resulted in 16- to 32-fold reductions in carbapenem MICs, whereas complementation with intact ompC resulted in a 2-fold reduction in carbapenem MICs. Additionally, blaOXA-232 expression increased 2.9-fold in a carbapenem-resistant isolate. Rapid development of high-level carbapenem resistance in initially carbapenem-susceptible OXA-232-producing R. ornithinolytica under selective pressure from carbapenem therapy highlights the diagnostic challenges in detecting Enterobacteriaceae strains producing this inefficient carbapenemase.

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Characterization of the Proliferating Cell Nuclear Antigen of Leishmania donovani Clinical Isolates and Its Association with Antimony Resistance

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01847-13 ◽

2014 ◽

Vol 58 (6) ◽

pp. 2997-3007 ◽

Cited By ~ 9

Author(s):

Rati Tandon ◽

Sharat Chandra ◽

Rajendra Kumar Baharia ◽

Sanchita Das ◽

Pragya Misra ◽

...

Keyword(s):

Clinical Isolate ◽

Proliferating Cell Nuclear Antigen ◽

Leishmania Donovani ◽

Clinical Isolates ◽

Resistant Isolate ◽

Nuclear Antigen ◽

Wild Type ◽

Content Type ◽

Sensitive Isolate ◽

Proliferating Cell

ABSTRACTPreviously, through a proteomic analysis, proliferating cell nuclear antigen (PCNA) was found to be overexpressed in the sodium antimony gluconate (SAG)-resistant clinical isolate compared to that in the SAG-sensitive clinical isolate ofLeishmania donovani. The present study was designed to explore the potential role of the PCNA protein in SAG resistance inL. donovani. For this purpose, the protein was cloned, overexpressed, purified, and modeled. Western blot (WB) and real-time PCR (RT-PCR) analyses confirmed that PCNA was overexpressed by ≥3-fold in the log phase, stationary phase, and peanut agglutinin isolated procyclic and metacyclic stages of the promastigote form and by ∼5-fold in the amastigote form of the SAG-resistant isolate compared to that in the SAG-sensitive isolate.L. donovaniPCNA (LdPCNA) was overexpressed as a green fluorescent protein (GFP) fusion protein in a SAG-sensitive clinical isolate ofL. donovani, and modulation of the sensitivities of the transfectants to pentavalent antimonial (SbV) and trivalent antimonial (SbIII) drugs was assessedin vitroagainst promastigotes and intracellular (J774A.1 cell line) amastigotes, respectively. Overexpression of LdPCNA in the SAG-sensitive isolate resulted in an increase in the 50% inhibitory concentrations (IC50) of SbV(from 41.2 ± 0.6 μg/ml to 66.5 ± 3.9 μg/ml) and SbIII(from 24.0 ± 0.3 μg/ml to 43.4 ± 1.8 μg/ml). Moreover, PCNA-overexpressing promastigote transfectants exhibited less DNA fragmentation compared to that of wild-type SAG-sensitive parasites upon SbIIItreatment. In addition, SAG-induced nitric oxide (NO) production was found to be significantly inhibited in the macrophages infected with the transfectants compared with that in wild-type SAG-sensitive parasites. Consequently, we infer that LdPCNA has a significant role in SAG resistance inL. donovaniclinical isolates, which warrants detailed investigations regarding its mechanism.

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Host Carbon Dioxide Concentration Is an Independent Stress for Cryptococcus neoformans That Affects Virulence and Antifungal Susceptibility

mBio ◽

10.1128/mbio.01410-19 ◽

2019 ◽

Vol 10 (4) ◽

Cited By ~ 1

Author(s):

Damian J. Krysan ◽

Bing Zhai ◽

Sarah R. Beattie ◽

Kara M. Misel ◽

Melanie Wellington ◽

...

Keyword(s):

Carbon Dioxide ◽

Cryptococcus Neoformans ◽

Carbon Dioxide Concentration ◽

Antifungal Drugs ◽

Clinical Isolates ◽

Mammalian Host ◽

Environmental Isolates ◽

Capsule Formation ◽

Content Type ◽

Virulence Traits

ABSTRACT The ability of Cryptococcus neoformans to cause disease in humans varies significantly among strains with highly related genotypes. In general, environmental isolates of pathogenic species such as Cryptococcus neoformans var. grubii have reduced virulence relative to clinical isolates, despite having no differences in the expression of the canonical virulence traits (high-temperature growth, melanization, and capsule formation). In this observation, we report that environmental isolates of C. neoformans tolerate host CO2 concentrations poorly compared to clinical isolates and that CO2 tolerance correlates well with the ability of the isolates to cause disease in mammals. Initial experiments also suggest that CO2 tolerance is particularly important for dissemination of C. neoformans from the lung to the brain. Furthermore, CO2 concentrations affect the susceptibility of both clinical and environmental C. neoformans isolates to the azole class of antifungal drugs, suggesting that antifungal testing in the presence of CO2 may improve the correlation between in vitro azole activity and patient outcome. IMPORTANCE A number of studies comparing either patient outcomes or model system virulence across large collections of Cryptococcus isolates have found significant heterogeneity in virulence even among strains with highly related genotypes. Because this heterogeneity cannot be explained by variations in the three well-characterized virulence traits (growth at host body temperature, melanization, and polysaccharide capsule formation), it has been widely proposed that additional C. neoformans virulence traits must exist. The natural niche of C. neoformans is in the environment, where the carbon dioxide concentration is very low (∼0.04%); in contrast, mammalian host tissue carbon dioxide concentrations are 125-fold higher (5%). We have found that the ability to grow in the presence of 5% carbon dioxide distinguishes low-virulence strains from high-virulence strains, even those with a similar genotype. Our findings suggest that carbon dioxide tolerance is a previously unrecognized virulence trait for C. neoformans.

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Epidemiology and Antifungal Susceptibility Profile of Aspergillus Species: Comparison between Environmental and Clinical Isolates from Patients with Hematologic Malignancies

Journal of Clinical Microbiology ◽

10.1128/jcm.02023-18 ◽

2019 ◽

Vol 57 (7) ◽

Cited By ~ 6

Author(s):

Sung-Yeon Cho ◽

Dong-Gun Lee ◽

Won-Bok Kim ◽

Hye-Sun Chun ◽

Chulmin Park ◽

...

Keyword(s):

Invasive Aspergillosis ◽

Cryptic Species ◽

Hematologic Malignancy ◽

Antifungal Susceptibility ◽

Hematologic Malignancies ◽

Clinical Isolates ◽

Environmental Isolates ◽

Content Type ◽

Culture Positive ◽

Global Data

ABSTRACT Global data on the epidemiology and susceptibility of Aspergillus are crucial in the management of invasive aspergillosis. Here, we aimed to determine the characteristics of clinical and environmental Aspergillus isolates, focusing mainly on hematologic malignancy patients. We prospectively collected all consecutive cases and clinical isolates of culture-positive proven/probable invasive aspergillosis patients from January 2016 to April 2018 and sampled the air inside and outside the hospital. Cryptic species-level identification of Aspergillus, antifungal susceptibilities, and cyp51 gene sequencing were performed, and clinical data were analyzed. This study was conducted as part of the Catholic Hematology Hospital Fungi Epidemiology (CAFÉ) study. A total of 207 proven/probable invasive aspergillosis and 102 clinical and 129 environmental Aspergillus isolates were included in this analysis. The incidence of proven/probable invasive aspergillosis was 1.3 cases/1,000 patient-days during the study period. Cryptic Aspergillus species accounted for 33.8%, with no differences in proportions between the clinical and environmental isolates. Section Nigri presented a high proportion (70.5%) of cryptic species, mainly from A. tubingensis and A. awamori: the former being dominant in environmental samples, and the latter being more common in clinical isolates (P < 0.001). Of 91 A. fumigatus isolates, azole-resistant A. fumigatus was found in 5.3% of all A. fumigatus isolates. Three isolates presented the TR34/L98H mutation of the cyp51A gene. Patients with invasive aspergillosis caused by azole-resistant A. fumigatus showed 100% all-cause mortality at 100 days. This study demonstrates the significant portion of cryptic Aspergillus species and clinical implications of azole resistance and underscores the comparison between clinical and environmental isolates.

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1189. A Comprehensive Characterization of the Emerging Carbapenem-Resistant Klebsiella pneumoniae Clinical Isolates From a Public Hospital in Lima, Peru

Open Forum Infectious Diseases ◽

10.1093/ofid/ofy210.1022 ◽

2018 ◽

Vol 5 (suppl_1) ◽

pp. S359-S360 ◽

Cited By ~ 1

Author(s):

Fiorella Krapp ◽

Catherine Amaro ◽

Karen Ocampo ◽

Lizeth Astocondor ◽

Noemi Hinostroza ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Dna Extraction ◽

Antibiotic Susceptibility ◽

Tertiary Care ◽

Clinical Isolates ◽

Molecular Characteristics ◽

Care Hospital ◽

Carbapenem Resistant ◽

Carbapenemase Gene ◽

String Test

Abstract Background In contrast with other countries in Latin America, Peru had been notoriously spared by the global dissemination of carbapenem-resistant Klebsiella pneumoniae (CR-Kp), until recently. Even though, isolated cases of KPC-producing K. pneumoniae had been reported since 2013, it was not until 2016 that the first outbreak of NDM- producing K. pneumoniae was described in Peru. By 2017, rapid emergence of CR-Kp took place in Hospital Cayetano Heredia (HCH), a tertiary care hospital in Lima. Here, we provide a description of clinical, microbiological and molecular characteristics of CR-Kp isolates recovered at HCH. Methods Retrospective review of all CR-Kp clinical isolates recovered at HCH until December 2017. Antibiotic susceptibility data were obtained during routine care (Vitek or disc diffusion) and was assessed using CLSI breakpoints. DNA extraction was performed by heat shock, and PCR was performed to assess carriage of blaNDM gene. String test was performed to detect hypermucoviscosity. Results The first case of CR-Kp in HCH dated from July 2015. Since then, a total of 69 CR-Kp clinical isolates, from 60 patients have been recovered until December 2017. A significant increase in the number of cases was observed during 2017 (Figure 1). The average age of patients was 55. Urinary, and respiratory sources of infection or colonization were the most common ones (35% and 30%, respectively), followed by blood stream (17%) and intraabdominal (10%) infections. Isolate recovery and DNA extraction was achieved in 40 cases. Of these, 15 (38%) had a positive PCR for blaNDM carbapenemase gene (Figure 2). Antibiotic susceptibility testing revealed that amikacin was the most effective antimicrobial with the rest of antimicrobials having extremely high rates of resistance (Figure 3). String test was positive in two of these isolates, suggesting that hypervirulent CR-KP might be emerging in this region. Conclusion An epidemic of CR-Kp has established in our hospital, representing the first one reported in Peru. The different mechanisms of carbapenem resistance found suggest a polyclonal expansion. Amikacin remains the only active antimicrobial within the routinely tested antibiotics, highlighting the need to add other antimicrobials to the routine panel. Disclosures All authors: No reported disclosures.

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Multiplecyp51A-Based Mechanisms Identified in Azole-Resistant Isolates of Aspergillus fumigatus from China

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00003-15 ◽

2015 ◽

Vol 59 (7) ◽

pp. 4321-4325 ◽

Cited By ~ 30

Author(s):

Musang Liu ◽

Rong Zeng ◽

Lili Zhang ◽

Dongmei Li ◽

Guixia Lv ◽

...

Keyword(s):

Aspergillus Fumigatus ◽

Clinical Isolates ◽

Resistant Isolate ◽

Azole Resistance ◽

Content Type ◽

Resistant Strains

ABSTRACTSeventy-twoA. fumigatusclinical isolates from China were investigated for azole resistance based on mutations ofcyp51A. We identified four azole-resistant strains, among which we found three strains highly resistant to itraconazole, two of which exhibit the TR34/L98H/S297T/F495I mutation, while one carries only the TR34/L98H mutation. To our knowledge, the latter has not been found previously in China. The fourth multiazole-resistant isolate (with only moderate itraconazole resistance) carries a new G432A mutation.

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Results from the China Antimicrobial Surveillance Network (CHINET) in 2017 of the In Vitro Activities of Ceftazidime-Avibactam and Ceftolozane-Tazobactam against Clinical Isolates of Enterobacteriaceae and Pseudomonas aeruginosa

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02431-18 ◽

2019 ◽

Vol 63 (4) ◽

Cited By ~ 19

Author(s):

Dandan Yin ◽

Shi Wu ◽

Yang Yang ◽

Qingyu Shi ◽

Dong Dong ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Clinical Isolates ◽

Surveillance Network ◽

Content Type ◽

Highly Active ◽

Microdilution Method ◽

Carbapenem Resistant ◽

Antimicrobial Surveillance ◽

Broth Microdilution Method

ABSTRACT The in vitro activities of ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C-T), and comparators were determined for 1,774 isolates of Enterobacteriaceae and 524 isolates of Pseudomonas aeruginosa collected by 30 medical centers from the China Antimicrobial Surveillance Network (CHINET) in 2017. Antimicrobial susceptibility testing was performed by the CLSI broth microdilution method, and blaKPC and blaNDM were detected by PCR for all carbapenem-resistant Enterobacteriaceae (CRE). Ceftazidime-avibactam demonstrated potent activity against almost all Enterobacteriaceae (94.6% susceptibility; MIC50, ≤0.25 mg/liter; MIC90, ≤0.25 to >32 mg/liter) and good activity against P. aeruginosa (86.5% susceptibility; MIC50/90, 2/16 mg/liter). Among the CRE, 50.8% (189/372 isolates) were positive for blaKPC-2, which mainly existed in ceftazidime-avibactam-susceptible Klebsiella pneumoniae isolates (92.1%, 174/189). Among the CRE, 17.7% (66/372 isolates) were positive for blaNDM, which mainly existed in strains resistant to ceftazidime-avibactam (71.7%, 66/92). Ceftolozane-tazobactam showed good in vitro activity against Escherichia coli and Proteus mirabilis (MIC50/90, ≤0.5/2 mg/liter; 90.5 and 93.8% susceptibility, respectively), and the rates of susceptibility of K. pneumoniae (MIC50/90, 2/>64 mg/liter) and P. aeruginosa (MIC50/90, 1/8 mg/liter) were 52.7% and 88.5%, respectively. Among the CRE strains, 28.6% of E. coli isolates and 85% of K. pneumoniae isolates were still susceptible to ceftazidime-avibactam, but only 7.1% and 1.9% of them, respectively, were susceptible to ceftolozane-tazobactam. The rates of susceptibility of the carbapenem-resistant P. aeruginosa isolates to ceftazidime-avibactam (65.7%) and ceftolozane-tazobactam (68%) were similar. Overall, both ceftazidime-avibactam and ceftolozane-tazobactam were highly active against clinical isolates of Enterobacteriaceae and P. aeruginosa recently collected across China, and ceftazidime-avibactam showed activity superior to that of ceftolozane-tazobactam against Enterobacteriaceae, whereas ceftolozane-tazobactam showed a better effect against P. aeruginosa.

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Genetic Diversity of Clinical and Environmental Vibrio parahaemolyticus Strains from the Pacific Northwest

Applied and Environmental Microbiology ◽

10.1128/aem.01531-12 ◽

2012 ◽

Vol 78 (24) ◽

pp. 8631-8638 ◽

Cited By ~ 55

Author(s):

Rohinee Paranjpye ◽

Owen S. Hamel ◽

Asta Stojanovski ◽

Martin Liermann

Keyword(s):

Pacific Northwest ◽

Vibrio Parahaemolyticus ◽

The United States ◽

Assessment Tools ◽

Clinical Isolates ◽

Environmental Isolates ◽

Content Type ◽

The Pacific ◽

Geographical Regions ◽

Thermostable Direct Hemolysin

ABSTRACTSince 1997, cases ofVibrio parahaemolyticus-related gastroenteritis from the consumption of raw oysters harvested in Washington State have been higher than historical levels. These cases have shown little or no correlation with concentrations of potentially pathogenicV. parahaemolyticus(positive for the thermostable direct hemolysin gene,tdh) in oysters, although significant concentrations oftdh+V. parahaemolyticusstrains were isolated from shellfish-growing areas in the Pacific Northwest (PNW). We compared clinical and environmental strains isolated from the PNW to those from other geographic regions within the United States and Asia for the presence of virulence-associated genes, including the thermostable direct hemolysin (tdh), the thermostable-related hemolysin (trh), urease (ureR), the pandemic group specific markersorf8andtoxRS, and genes encoding both type 3 secretion systems (T3SS1 and T3SS2). The majority of clinical strains from the PNW were positive fortdh,trh, andureRgenes, while a significant proportion of environmental isolates weretdh+buttrhnegative. Hierarchical clustering grouped the majority of these clinical isolates into a cluster distinct from that including the pandemic strain RIMD2210633, clinical isolates from other geographical regions, andtdh+,trh-negative environmental isolates from the PNW. We detected T3SS2-related genes (T3SS2β) in environmental strains that weretdhandtrhnegative. The presence of significant concentrations oftdh+,trh-negative environmental strains in the PNW that have not been responsible for illness and T3SS2β intdh- andtrh-negative strains emphasizes the diversity in this species and the need to identify additional virulence markers for this bacterium to improve risk assessment tools for the detection of this pathogen.

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