543. Biocide Resistance Genes in Klebsiella spp. Infections from Trauma Patients in Iraq and Afghanistan

Abstract Background Biocides play an integral role in infection control. Paralleling concern about rising incidence of multidrug-resistant (MDR) organisms is a concern for resistance to biocides. In small studies, several genes involved in the production of efflux pump proteins have been identified as markers of biocide resistance in Klebsiella spp., namely cepA, qacA, qacE, qac∆E, and acrA. This study aimed to analyze the Klebsiella spp. isolates of a previously defined military trauma group with a high incidence of MDR organisms for the presence of these genes and their correlation with other resistance. Methods All infecting K. pneumoniae, K. variicola, and K. quasipneumoniae isolates archived by the Trauma Infectious Disease Outcomes Study (June 2009–December 2014) were selected. Additionally, all colonizing isolates linked with infecting isolates were included; the remainder to total 50 MDR and 46 non-MDR colonizing isolates were chosen randomly. Antimicrobial identification and susceptibilities were determined by CLSI criteria using the BD Phoenix Automated Microbiology System. PCR according to published methods for cepA, qacA, qacE, qac∆E, and acrA was accomplished in duplicate. MDR was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of an ESBL or KPC. Results A total of 237 isolates (221 K. pneumoniae, 10 K. variicola, 6 K. quasipneumoniae) met inclusion criteria, of which 149 (63%) were MDR. All isolates had been exposed to antimicrobials prior to isolation. Of all isolates, 234 (98%) carried cepA: 218 (98%) K. pneumoniae carried cepA, 10 (100%) K. variicola carried cepA, and 6 (100%) of K. quasipneumoniae carried cepA. In addition, 148 (62%) isolates with cepA were MDR. One (10%) K. variicola isolate carried qacE along with cepA. This isolate was the only MDR K. variicola. None of the isolates carried qacA, qac∆E, or acrA. Conclusion We confirmed the near universal presence of the cepA biocide resistance gene in Klebsiella spp. isolated from trauma patients in Iraq and Afghanistan. In the largest evaluation of biocide resistance genes in Klebsiella spp. to our knowledge, the presence of qacA, qacE, qac∆E, and acrA was less common than has been reported elsewhere. Disclosures All authors: No reported disclosures.

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Ethidium Bromide MIC Screening for Enhanced Efflux Pump Gene Expression or Efflux Activity in Staphylococcus aureus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01058-10 ◽

2010 ◽

Vol 54 (12) ◽

pp. 5070-5073 ◽

Cited By ~ 49

Author(s):

Diixa Patel ◽

Christos Kosmidis ◽

Susan M. Seo ◽

Glenn W. Kaatz

Keyword(s):

Staphylococcus Aureus ◽

Ethidium Bromide ◽

Efflux Pump ◽

Large Strain ◽

Efflux Pumps ◽

Multidrug Resistant ◽

Reverse Transcription Pcr ◽

Biocide Resistance ◽

Straightforward Method ◽

Short Period

ABSTRACT Multidrug resistance efflux pumps contribute to antimicrobial and biocide resistance in Staphylococcus aureus. The detection of strains capable of efflux is time-consuming and labor-intensive using currently available techniques. A simple and inexpensive method to identify such strains is needed. Ethidium bromide is a substrate for all but one of the characterized S. aureus multidrug-resistant (MDR) efflux pumps (NorC), leading us to examine the utility of simple broth microtiter MIC determinations using this compound in identifying efflux-proficient strains. Quantitative reverse transcription-PCR identified the increased expression of one or more MDR efflux pump genes in 151/309 clinical strains (49%). Ethidium bromide MIC testing was insensitive (48%) but specific (92%) in identifying strains with gene overexpression, but it was highly sensitive (95%) and specific (99%) in identifying strains capable of ethidium efflux. The increased expression of norA with or without other genes was most commonly associated with efflux, and in the majority of cases that efflux was inhibited by reserpine. Ethidium bromide MIC testing is a simple and straightforward method to identify effluxing strains and can provide accurate predictions of efflux prevalence in large strain sets in a short period of time.

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1184. Resistance Patterns and Susceptibility Analysis of Klebsiella pneumoniae Infections in Service Members Who Sustained Trauma in Iraq and Afghanistan

Open Forum Infectious Diseases ◽

10.1093/ofid/ofy210.1017 ◽

2018 ◽

Vol 5 (suppl_1) ◽

pp. S357-S358

Author(s):

John Kiley ◽

Katrin Mende ◽

Susan J Kaiser ◽

Leigh Carson ◽

Dan Z Lu ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Common Species ◽

Multidrug Resistant ◽

Trauma Patients ◽

Disease Outcomes ◽

Antibiotic Susceptibilities ◽

Military Trauma ◽

Resistance Patterns ◽

Outcomes Study ◽

Susceptibility And Resistance

Abstract Background Klebsiella pneumoniae was the third most common species of multidrug-resistant (MDR) Gram-negative organism in military trauma patients injured in Iraq and Afghanistan (2009–2014). This study aims to characterize the antimicrobial susceptibility and resistance patterns of K. pneumoniae isolates in these patients. Methods All infecting K. pneumoniae isolates (IKpI) archived by the Trauma Infectious Disease Outcomes Study (TIDOS) and 96 colonizing isolates (CKpI) from groin swabs were included (6/09-12/14). All CKpI linked with IKpI were included; the remainder to total 50 MDR and 46 non-MDR CKpI were chosen randomly. Antimicrobial identification and susceptibilities were determined by CLSI criteria using the BD Phoenix Automated Microbiology System. MDR was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems, and/or fluoroquinolones or production of an ESBL or KPC. Results Of 588 K. pneumoniae archived isolates, 237 isolates were included in the analysis (141 IKpI and 96 CKpI). IKpI sources were 40% wound, 22% respiratory, 20% blood, 9% urine, and 9% other. Antibiotic susceptibilities for IKpI were: cefazolin (CFZ) 20%, ceftriaxone 30%, levofloxacin 62%, piperacillin–tazobactam (PTZ) 41%, meropenem 96%, and amikacin 89%. MDR IKpI and CKpI were more likely to have had prior fluoroquinolone (82% vs. 18%, P < 0.01) or anti-pseudomonal penicillin (53% vs. 47%, P < 0.01) exposure. Seventeen patients had CKpI cultured at a median of 5 days (IQR 2–17) before a subsequent IKpI with 11 (65%) having MDR CKpI. All IKpI isolated after MDR CKpI were also MDR. Among IKpI recovered after non-MDR CKpI, new resistance was noted in 1 IKpI to gentamicin (200 days post-CKpI), 1 IKpI to ertapenem (7 days post-CKpI), two IKpI to CFZ (10 days and 17 days, respectively), and 1 IKpI to PTZ (19 days post-CKpI). Serial isolates of IKpI had similar MDR status (63% initial IKpI were MDR, whereas 76% of subsequent IKpI were MDR). Conclusion K. pneumoniae isolates in military trauma patients from Iraq and Afghanistan had challenging resistance patterns. Prior exposure to fluoroquinolones and anti-pseudomonal penicillins were associated with MDR K. pneumoniae isolation. MDR status of CKpI predicted subsequent IKpI MDR status. Disclosures All authors: No reported disclosures.

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RND-Type Efflux Pumps in Multidrug-Resistant Clinical Isolates of Acinetobacter baumannii: Major Role for AdeABC Overexpression and AdeRS Mutations

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02556-12 ◽

2013 ◽

Vol 57 (7) ◽

pp. 2989-2995 ◽

Cited By ~ 113

Author(s):

Eun-Jeong Yoon ◽

Patrice Courvalin ◽

Catherine Grillot-Courvalin

Keyword(s):

Acinetobacter Baumannii ◽

Efflux Pump ◽

Regulatory System ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Clinical Settings ◽

Two Component System ◽

Content Type ◽

High Incidence ◽

Two Component

ABSTRACTIncreased expression of chromosomal genes for resistance-nodulation-cell division (RND)-type efflux systems plays a major role in the multidrug resistance (MDR) ofAcinetobacter baumannii. However, the relative contributions of the three most prevalent pumps, AdeABC, AdeFGH, and AdeIJK, have not been evaluated in clinical settings. We have screened 14 MDR clinical isolates shown to be distinct on the basis of multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) for the presence and overexpression of the three Ade efflux systems and analyzed the sequences of the regulators AdeRS, a two-component system, for AdeABC and AdeL, a LysR-type regulator, for AdeFGH. GeneadeBwas detected in 13 of 14 isolates, andadeGand the intrinsicadeJgene were detected in all strains. Significant overexpression ofadeBwas observed in 10 strains, whereas only 7 had moderately increased levels of expression of AdeFGH, and none overexpressed AdeIJK. Thirteen strains had reduced susceptibility to tigecycline, but there was no correlation between tigecycline MICs and the levels of AdeABC expression, suggesting the presence of other mechanisms for tigecycline resistance. No mutations were found in the highly conserved LysR regulator of the nine strains expressing AdeFGH. In contrast, functional mutations were found in conserved domains of AdeRS in all the strains that overexpressed AdeABC with two mutational hot spots, one in AdeS near histidine 149 suggesting convergent evolution and the other in the DNA binding domain of AdeR compatible with horizontal gene transfer. This report outlines the high incidence of AdeABC efflux pump overexpression in MDRA. baumanniias a result of a variety of single mutations in the corresponding two-component regulatory system.

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502. Klebsiella variicola Infections in Service Members Who Sustained Trauma in Iraq and Afghanistan

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.571 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S243-S244

Author(s):

John L Kiley ◽

Katrin Mende ◽

Miriam Beckius ◽

Susan Kaiser ◽

M Leigh Carson ◽

...

Keyword(s):

Injury Severity ◽

Length Of Hospital Stay ◽

Patient Characteristics ◽

Invasive Disease ◽

Multidrug Resistant ◽

Trauma Patients ◽

Disease Outcomes ◽

Military Trauma ◽

Pcr Targeting ◽

Selection Of

Abstract Background Recent work has argued that genus Klebsiella is best divided into 3 clades: K. pneumoniae (Kp), K. quasipneumoniae (Kq), and K. variicola (Kv). Kv has drawn attention from reports of higher mortality and virulence. We evaluated a previously defined group of military trauma patients with Klebsiella infections for the presence of Kv, described clinical and isolate characteristics, and compared Kv and Kp groups. Methods All initial and serial (≥7 days from prior isolate) infecting Kp isolates (identified by clinical laboratories without the ability to speciate Kq and Kv) were collected from the Trauma Infectious Disease Outcomes Study (6/09–12/14). Additionally, a previously defined group of colonizing isolates linked to the infecting isolates and a selection of random colonizers were included from groin swabs. DNA extraction and PCR targeting Kv per published methods was performed. Antimicrobial susceptibilities were determined using the BD Phoenix Automated Microbiology System and CLSI criteria. Multidrug resistance was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of ESBL or KPC. Results Of 237 archived Kp isolates (from 122 patients), 10 (4%) were identified as Kv by PCR (from 8 [7%] patients). The Kv sources were 4 from blood (40%), 1 intra-abdominal (10%) and 5 from groin (50%). Six (3%) isolates were identified as Kq (4 from groin and 2 from respiratory specimens). The Kv and Kp patients were all males, with a median age of 25 (IQR 21–46) and 23 (IQR 21–28), length of hospital stay of 24 days (IQR: 5–106) and 53 days (IQR 36–74), and Injury Severity Score of 21 (IQR: 10–50) and 38 (IQR: 30–45), respectively. There were no deaths in the Kv group compared with 4 with Kp. Infecting Kv isolates were more likely to be from blood compared with Kp (80% vs. 17%, P = 0.04). No infecting Kv isolates were multidrug-resistant compared with 70% of infecting Kp isolates (P < 0.01). Conclusion Kv represented 4% of the previously identified Kp isolates in this population. Patient characteristics were similar in both groups. While Kv was less resistant than Kp, it was more likely to be associated with invasive disease in this group. Disclosures All authors: No reported disclosures.

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Self-inhibitory peptides targeting the Neisseria gonorrhoeae MtrCDE efflux pump increase antibiotic susceptibility

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01542-21 ◽

2021 ◽

Author(s):

Benjamin J. Evert ◽

Valentin A. Slesarenko ◽

Jilsy M. J. Punnasseril ◽

Taha ◽

Jian Zhan ◽

...

Keyword(s):

Antibiotic Resistance ◽

Neisseria Gonorrhoeae ◽

Efflux Pump ◽

Multidrug Resistant ◽

Dependent Manner ◽

Inhibitory Peptides ◽

Rising Incidence ◽

Resistant Strains ◽

Protein Components ◽

Dose Dependent

Neisseria gonorrhoeae is an increasing public health threat due to rapidly rising incidence and antibiotic resistance. There are an estimated 106 million cases per year worldwide, there is no vaccine available to prevent infection, and N. gonorrhoeae strains have emerged that are resistant to all antibiotics routinely used to treat the infection. In many strains, antibiotic resistance is mediated by overexpression of the MtrCDE efflux pump, which enables the bacteria to transport toxic antibiotics out of the cell. Genetic mutations that inactivate MtrCDE have previously been shown to render resistant strains susceptible to certain antibiotics. Here we have shown that peptides rationally-designed to target and disrupt the activity of each of the three protein components of MtrCDE were able to increase the susceptibility of N. gonorrhoeae strains to antibiotics, in a dose-dependent manner and with no toxicity to human cells. Co-treatment of bacteria with subinhibitory concentrations of peptide led to 2-64 fold increases in the susceptibility to erythromycin, azithromycin, ciprofloxacin and/or ceftriaxone in N. gonorrhoeae strains FA1090, WHO K, WHO P and WHO X. The co-treatment experiments with peptides P-MtrC1 and P-MtrE1 resulted in increased susceptibility to azithromycin, ciprofloxacin and ceftriaxone in WHO P and WHO X that was of the same magnitude seen in MtrCDE mutants. P-MtrE1 was able to change the azithromycin resistance profile of WHO P from resistant to susceptible. Data presented here demonstrate that these peptides could be developed for use as a dual treatment with existing antibiotics to treat multidrug-resistant gonococcal infections.

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Antibacterial Resistance Pattern in Clinical and Non-clinical Bacteria by Phenotypic and Genotypic Assessment

Journal of Pure and Applied Microbiology ◽

10.22207/jpam.15.4.49 ◽

2021 ◽

Author(s):

Mohamed Shawky ◽

Waleed B. Suleiman ◽

Ayman A. Farrag

Keyword(s):

Resistance Genes ◽

Bacterial Infections ◽

Efflux Pump ◽

Methicillin Resistance ◽

Genetic Resistance ◽

Multidrug Resistant ◽

Resistance Pattern ◽

Klebsiella Pneumonia ◽

Bacterial Isolates ◽

The Impact

Bacterial infections represent a very serious problem that threatens human health, antibiotics were designed to attack the causative agents of infectious diseases, but some bacterial pathogens became virulent and resistant to antibiotics by different mechanisms, resistance genes represented one of those mechanisms. This study attempts to screen the existence of five different resistance genes (mecA, TEM, FemA, MexD, and AmpC) among 25 bacterial isolates divided into two groups the first was non-clinical bacterial type strains including Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella typhi, and the other group includes some clinical bacterial isolates. Evaluation of their susceptibilities to different 12 antibiotic discs and attempting to find the relationship between genotype and phenotype assessment. Different responses were reported which varied from slightly susceptible to multidrug-resistant such as P. aeruginosa and K. pneumonia which could be considered as multidrug-resistant strains. Therefore, detection of resistance gene became crucial and critical to recognize the mechanism of resistance, five pairs of primers were included to investigate five responsible genes belonging to beta-lactamases, efflux pump, and methicillin resistance. Conclusively, the PCR technique is a very accurate tool to check the genetic resistance whether being expressed to phenotype or not. Moreover, the clinical bacterial isolates appeared more resistant that reflecting the impact of the surrounding environment on bacterial behavior.

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A novel mobile RND-type efflux pump gene cluster, tmexC3D2-toprJ3, confers tigecycline resistance in Pseudomonas alcaligenes

10.1101/2021.07.26.453812 ◽

2021 ◽

Author(s):

Shotaro Maehana ◽

Ryotaro Eda ◽

Nagi Niida ◽

Aki Hirabayashi ◽

Kouji Sakai ◽

...

Keyword(s):

Gene Cluster ◽

Resistance Genes ◽

Efflux Pump ◽

Multidrug Resistant ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Genomic Studies ◽

Rnd Efflux Pumps ◽

Pseudomonas Alcaligenes ◽

Hospital Sewage

Tigecycline exhibits promising activity against multidrug-resistant gram-negative bacteria (MDR-GNB). However, mobile tigecycline resistance genes, such as tmexCD-toprJ encoding RND efflux pumps, have emerged. Here, we identified a novel tmexC3D2-toprJ3 gene cluster in tigecycline- and carbapenem-nonsusceptible Pseudomonas alcaligenes isolates from hospital sewage in Japan in 2020. tmexC3D2-toprJ3 and two copies of blaIMP-1 were located on the chromosome. This suggests that diverse tmexCD-toprJ-like genes have spread among MDR-GNB worldwide and further epidemiological genomic studies are needed.

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