Emergence of Multidrug-Resistant New Delhi Metallo-β-Lactamase-1-Producing Klebsiella pneumoniae in Egypt

Emergence of extensive drug resistance and high prevalence of multidrug resistance among clinical Proteus mirabilis isolates in Egypt

BACKGROUND

Proteus mirabilis is an opportunistic pathogen that has been held responsible for numerous nosocomial and community-acquired infections which are difficult to be controlled because of its diverse antimicrobial resistance mechanisms.

METHODS

Antimicrobial susceptibility patterns of P. mirabilis isolates collected from different clinical sources in Mansoura University Hospitals, Egypt was determined. Moreover, the underlying resistance mechanisms and genetic relatedness between isolates were investigated.

RESULTS

Antimicrobial susceptibility testing indicated elevated levels of resistance to different classes of antimicrobials among the tested P. mirabilis clinical isolates (n = 66). ERIC-PCR showed great diversity among the tested isolates. Six isolates (9.1%) were XDR while all the remaining isolates were MDR. ESBLs and AmpCs were detected in 57.6% and 21.2% of the isolates, respectively, where blaTEM, blaSHV, blaCTX-M, blaCIT-M and blaAmpC were detected. Carbapenemases and MBLs were detected in 10.6 and 9.1% of the isolates, respectively, where blaOXA-48 and blaNDM-1 genes were detected. Quinolone resistant isolates (75.8%) harbored acc(6')-Ib-cr, qnrD, qnrA, and qnrS genes. Resistance to aminoglycosides, trimethoprim-sulfamethoxazole and chloramphenicol exceeded 80%. Fosfomycin was the most active drug against the tested isolates as only 22.7% were resistant. Class I or II integrons were detected in 86.4% of the isolates. Among class I integron positive isolates, four different gene cassette arrays (dfrA17- aadA5, aadB-aadA2, aadA2-lnuF, and dfrA14-arr-3-blaOXA-10-aadA15) and two gene cassettes (dfrA7 and aadA1) were detected. While class II integron positive isolates carried four different gene cassette arrays (dfrA1-sat1-aadA1, estXVr-sat2-aadA1, lnuF- dfrA1-aadA1, and dfrA1-sat2).

CONCLUSION

P. Mirabilis ability to acquire resistance determinants via integrons may be held responsible for the elevated rates of antimicrobial resistance and emergence of XDR or even PDR strains limiting the available therapeutic options for management of infections caused by those strains.

Molecular characterization of hypermucoviscous carbapenemase-encoding Klebsiella pneumoniae isolates from an Egyptian hospital

This study aimed to screen antibiotic resistance and virulence genes in carbapenem-resistant hypermucoviscous Klebsiella pneumoniae isolates from an Egyptian hospital. Among 38 previously confirmed carbapenem-nonsusceptible K. pneumoniae isolates, a string test identified three isolates as positive for hypermucoviscosity. Phenotypic characterization and molecular detection of carbapenemase- and virulence-encoding genes were performed. PCR-based multilocus sequence typing and phylogenetics were used to determine the clonality and global epidemiology of the strains. The coexistence of virulence and resistance genes in the isolates was analyzed statistically using a chi-square test. Three isolates showed the presence of carbapenemase-encoding genes (blaNDM, blaVIM, and blaIMP), adhesion genes (fim-H-1 and mrkD), and siderophore genes (entB); the isolates belonged to sequence types (STs) 101, 1310, and 1626. The relatedness between these sequence types and the sequence types of globally detected hypermucoviscous K. pneumoniae that also harbor carbapenemases was determined. Our analysis showed that the resistance and virulence profiles were not homogenous. Phylogenetically, different clones clustered together. There was no significant association between the presence of resistance and virulence genes in the isolates. There is a need for periodic surveillance of the healthcare settings in Egypt and globally to understand the true epidemiology of carbapenem-resistant, hypermucoviscous K. pneumoniae.

Review and analysis of the overlapping threats of carbapenem and polymyxin resistant E. coli and Klebsiella in Africa

BACKGROUND

Carbapenem-resistant Enterobacterales are among the most serious antimicrobial resistance (AMR) threats. Emerging resistance to polymyxins raises the specter of untreatable infections. These resistant organisms have spread globally but, as indicated in WHO reports, the surveillance needed to identify and track them is insufficient, particularly in less resourced countries. This study employs comprehensive search strategies with data extraction, meta-analysis and mapping to help address gaps in the understanding of the risks of carbapenem and polymyxin resistance in the nations of Africa.

METHODS

Three comprehensive Boolean searches were constructed and utilized to query scientific and medical databases as well as grey literature sources through the end of 2019. Search results were screened to exclude irrelevant results and remaining studies were examined for relevant information regarding carbapenem and/or polymyxin(s) susceptibility and/or resistance amongst E. coli and Klebsiella isolates from humans. Such data and study characteristics were extracted and coded, and the resulting data was analyzed and geographically mapped.

RESULTS

Our analysis yielded 1341 reports documenting carbapenem resistance in 40 of 54 nations. Resistance among E. coli was estimated as high (> 5%) in 3, moderate (1-5%) in 8 and low (< 1%) in 14 nations with at least 100 representative isolates from 2010 to 2019, while present in 9 others with insufficient isolates to support estimates. Carbapenem resistance was generally higher among Klebsiella: high in 10 nations, moderate in 6, low in 6, and present in 11 with insufficient isolates for estimates. While much less information was available concerning polymyxins, we found 341 reports from 33 of 54 nations, documenting resistance in 23. Resistance among E. coli was high in 2 nations, moderate in 1 and low in 6, while present in 10 with insufficient isolates for estimates. Among Klebsiella, resistance was low in 8 nations and present in 8 with insufficient isolates for estimates. The most widespread associated genotypes were, for carbapenems, blaOXA-48, blaNDM-1 and blaOXA-181 and, for polymyxins, mcr-1, mgrB, and phoPQ/pmrAB. Overlapping carbapenem and polymyxin resistance was documented in 23 nations.

CONCLUSIONS

While numerous data gaps remain, these data show that significant carbapenem resistance is widespread in Africa and polymyxin resistance is also widely distributed, indicating the need to support robust AMR surveillance, antimicrobial stewardship and infection control in a manner that also addresses broader animal and environmental health dimensions.

Evaluation of ERIC-PCR and MALDI-TOF as typing tools for multidrug resistant Klebsiella pneumoniae clinical isolates from a tertiary care center in India

Background and aim

Multidrug resistant Klebsiella pneumoniae is associated with nosocomial infections in both outbreak and non-outbreak situations. The study intends to evaluate the potential of enterobacterial repetitive intergenic consensus- polymerase chain reaction (ERIC-PCR), a genomic based typing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) proteomic-based typing techniques for clonal relatedness among multidrug resistant Klebsiella pneumoniae isolates.

Methodology

Multidrug resistant clinical isolates of Klebsiella pneumoniae (n = 137) were collected from March 2019 to February 2020. Identification and protein-based phylogenetic analysis were performed by MALDI-TOF MS. Genomic typing was done by ERIC-PCR and analyzed by an online data analysis service (PyElph). Dice method with unweighted pair group method with arithmetic mean (UPGMA) program was used to compare the ERIC profiles. The samples were also evaluated by PCR for the presence of genes encoding carbapenemases, extended spectrum beta lactamases (ESBLs) and mobile colistin resistance-1 (mcr1).

Result and conclusion

The study presents ERIC-PCR as more robust and better discriminatory typing tool in comparison to MALDI-TOF for clonal relatedness in multidrug resistant K. pneumoniae clinical isolates. Isolates were typed into 40 ERIC types, and six groups by MALDI-TOF-MS. PCR-based analysis revealed that all the strains harbored two or more ESBL and carbapenemase genes. None of the isolates revealed the presence of the plasmid mediated mcr-1 gene for colistin resistance.

Characterization of Carbapenem-Resistant K. Pneumoniae Isolated from Intensive Care Units of Zagazig University Hospitals

The advent of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant challenge to public health, as carbapenems are typically employed as a last resort to treat nosocomial infections caused by such organisms, especially in intensive care units (ICUs). This study aims to characterize the CRKP isolated from patients admitted to the Zagazig University Hospitals (ZUHs) ICU in Egypt. About 56.2%, 41.0%, and 32.4% of the isolates indicated the presence of bla_NDM, bla_OXA-48, and bla_KPC, respectively. Carbapenemase-encoding genes were found in many isolates, and bla_NDM was the most predominant gene. Nevertheless, this situation has become a heavy burden in developing countries, including Egypt, and is associated with substantial morbidity, mortality, and increased healthcare expenses.

Biotyping, Virulotyping and Biofilm Formation Ability of ESBL-Klebsiella pneumoniae Isolates from Nosocomial Infections

The aim of this study was to investigate the frequency, molecular characterization, virulence genes, resistance genes and antimicrobial profile of nosocomial extended spectrum beta lactamase producing Klebsiella species. A total of 22 (12.2%) K. pneumoniae strains were isolated from 180 clinical samples collected from hospitalized patients in Egypt. K. pneumoniae biotypes were B1 (72.8%), B3 (13.6%) and B4 (13.6%). The isolates were classified for the capsular serotypes, 86.4% (20/22) were of K1 serotype, while only two isolates (13.64%) were of K2 serotype. Hypermucoviscous K. pneumoniae isolates accounted for 68.2%. Biofilm formation ability of K. pneumoniae was determined by microtitre plate method. The majority of the isolates (40.9%) were moderate biofilm producers, while 27.3% were strong biofilm producers. All K. pneumoniae strains were positive for fimH and traT genes, while magA was identified in only 63.6% of the isolates. The antibiotic susceptibility profile of the isolates (n=22) was determined by the disc diffusion technique using 23 different antibiotics. Streptomycin and imipenem are the most effective antibiotics against 22 tested K. pneumoniae isolates with sensitivity rates of 63.64% and 54.54%, respectively. All tested K. pneumoniae isolates showed high resistance to amoxicillin∕clavulanate (100%), cefuroxime (100%) and ceftazidime (95.45%). Extended spectrum beta lactamases (ESBL) production and the presence of ESBL related genes were tested in the isolates. All the isolates tested positive for blaVIM, NDM1, and blaTEM, while only 81.8 percent tested positive for the blaSHV gene. Increasing antimicrobial resistance in K. pneumoniae causing nosocomial infections limits the use of antimicrobial agents for treatment. Furthermore, the spread of biofilm, multiple drug resistant and ESBL-producing K. pneumoniae isolates is a public threat for hospitalized patients.

Phenotype-genotype correlations among carbapenem-resistant Enterobacterales recovered from four Egyptian hospitals with the report of SPM carbapenemase

Background

Carbapenem-resistant Enterobacterales (CRE), currently listed by the World Health Organization (WHO) as top priority critical pathogens, are a major global menace to human health. In low- and middle-income countries (LMICs) the threat is mounting fueled by selective pressures caused by antibiotic abuse and inadequate diagnostic resources.

Methods

This study phenotypically and genotypically characterized carbapenem resistance among 115 Enterobacterales isolates including 76 Klebsiella (K.) pneumoniae, 19 Escherichia (E.) coli, 14 Shigella (S.) sonnei, 5 Enterobacter (E.) cloacae, and 1 Proteus (P.) mirabilis.

Results

Ninety-three isolates (80.9%) were carbapenem-resistant with an alarming 57.5% carbapenem non-susceptibility in isolates collected from the outpatient department. Molecular characterization of the carbapenemases (CPases) encoding genes showed that bla_NDM (80.5%) was the most prevalent; it was detected in 62 isolates (54 K. pneumoniae, 6 E. coli and 2 S. sonnei), followed by bla_VIM (36.4%) which was observed in 28 isolates (24 K. pneumoniae, 3 E. coli and 1 E. cloacae). Other CPases included bla_KPC (28.6%; in 20 K. pneumoniae, 1 E. coli and 1 S. sonnei), bla_OXA-48 (26%; in 17 K. pneumoniae, 1 E. coli,1 E. cloacae and 1 P. mirabilis), bla_IMP (6.5%; in 5 K. pneumoniae) and bla_SPM (1.3%; in K. pneumoniae). Notably more than half of the Enterobacterales isolates (54.5%) co-harboured more than one CPase-encoding gene. Co-existence of bla_NDM and bla_VIM genes was the most dominant (31.2%), followed by association of bla_NDM and bla_KPC (24.7%), then bla_VIM and bla_KPC (13%). Moreover, the effects of different genotypes on meropenem MIC values were assessed, and a statistically significant difference between the genotype (Ambler classes A and B) and the genotype (Ambler classes B and D) was recorded.

Conclusion

The current findings may serve for a better understanding of the context of CRE in Egypt, associated drivers and CPases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01061-7.

Prevalence and characterization of antimicrobial resistance among gram-negative bacteria isolated from febrile hospitalized patients in central Ethiopia

BACKGROUND

Infectious diseases are among the leading causes of death in many low-income countries, such as Ethiopia. Without reliable local data concerning causative pathogens and antimicrobial resistance, empiric treatment is suboptimal. The objective of this study was to characterize gram-negative bacteria (GNB) as pathogens and their resistance pattern in hospitalized patients with infections in central Ethiopia.

METHODS

Patients ≥ 1 year of age with fever admitted to the Asella Referral and Teaching Hospital from April 2016 to June 2018 were included. Blood and other appropriate clinical specimens were collected and cultured on appropriate media. Antibiotic susceptibility testing (AST) was performed using the Kirby-Bauer method and VITEK® 2. Species identification and detection of resistance genes were conducted using MALDI-ToF MS (VITEK® MS) and PCR, respectively.

RESULTS

Among the 684 study participants, 54.2% were male, and the median age was 22.0 (IQR: 14-35) years. Blood cultures were positive in 5.4% (n = 37) of cases. Among other clinical samples, 60.6% (20/33), 20.8% (5/24), and 37.5% (3/8) of swabs/pus, urine and other body fluid cultures, respectively, were positive. Among 66 pathogenic isolates, 57.6% (n = 38) were GNB, 39.4% (n = 26) were gram-positive, and 3.0% (n = 2) were Candida species. Among the isolated GNB, 42.1% (16/38) were Escherichia coli, 23.7% (9/38) Klebsiella pneumoniae and 10.5% (4/38) Pseudomonas aeruginosa. In total, 27/38 gram-negative isolates were available for further analysis. Resistance rates were as follows: ampicillin/sulbactam, 92.6% (n = 25); cefotaxime, 88.9% (n = 24); ceftazidime, 74.1% (n = 20); cefepime, 74.1% (n = 20); gentamicin, 55.6% (n = 15); piperacillin/tazobactam, 48.1% (n = 13); meropenem, 7.4% (n = 2); and amikacin, 3.7% (n = 1). The bla_NDM-1 gene was detected in one K. pneumoniae and one Acinetobacter baumannii isolate, which carried an additional bla_OXA-51 gene. The ESBL enzymes were detected in 81.5% (n = 22) of isolates as follows: TEM, 77.2% (n = 17); CTX-M-1 group, 68.2% (n = 15); SHV group, 27.3% (n = 6); and CTX-M-9 group, 9.1% (n = 2). Based on the in vitro antimicrobial susceptibility results, empiric treatment initiated in 13 of 18 (72.2%) patients was likely ineffective.

CONCLUSION

We report a high prevalence of ESBL-producing bacteria (81.5%) and carbapenem resistance (7.4%), with more than half of GNB carrying two or more ESBL enzymes resulting in suboptimal empiric antibiotic therapy. These findings indicate a need for local and national antimicrobial resistance surveillance and the strengthening of antimicrobial stewardship programs.

Comparative genome analysis of colistin-resistant OXA-48-producing Klebsiella pneumoniae clinical strains isolated from two Iranian hospitals

BACKGROUND

Carbapenemase-producing Klebsiella pneumoniae (CP-KP) is becoming extensively disseminated in Iranian medical centers. Colistin is among the few agents that retains its activity against CP-KP. However, the administration of colistin for treatment of carbapenem-resistant infections has increased resistance against this antibiotic. Therefore, the identification of genetic background of co-carbapenem, colistin-resistance K. pneumoniae (Co-CCRKp) is urgent for implementation of serious infection control strategies.

METHODS

Fourteen Co-CCRKp strains obtained from routine microbiological examinations were subjected to molecular analysis of antimicrobial resistance (AMR) using whole genome sequencing (WGS).

RESULTS

Nine of 14 K. pneumoniae strains belonged to sequence type (ST)-11 and 50% of the isolates had K-locus type 15. All strains carried blaOXA-48 except for P26. blaNDM-1 was detected in only two plasmids associated with P6 and P26 strains belonging to incompatibility (Inc) groups; IncFIB, IncHI1B and IncFII. No blaKPC, blaVIM and blaIMP were identified. Multi-drug resistant (MDR) conjugative plasmids were identified in strains P6, P31, P35, P38 and P40. MICcolistin of K. pneumoniae strains ranged from 4 to 32 µg/ml. Modification of PmrA, PmrB, PhoQ, RamA and CrrB regulators as well as MgrB was identified as the mechanism of colistin resistance in our isolates. Single amino acid polymorphysims (SAPs) in PhoQ (D150G) and PmrB (R256G) were identified in all strains except for P35 and P38. CrrB was absent in P37 and modified in P7 (A200E). Insertion of ISKpn72 (P32), establishment of stop codon (Q30*) (P35 and P38), nucleotides deletion (P37), and amino acid substitution at position 28 were identified in MgrB (P33 and P42). None of the isolates were positive for plasmid-mediated colistin resistance (mcr) genes. P35 and P38 strains carried iutA, iucD, iucC, iucB and iucA genes and are considered as MDR-hypervirulent strains. P6, P7 and P43 had ICEKp4 variant and ICEKp3 was identified in 78% of the strains with specific carriage in ST11.

CONCLUSION

In our study, different genetic modifications in chromosomal coding regions of some regulator genes resulted in phenotypic resistance to colistin. However, the extra-chromosomal colistin resistance through mcr genes was not detected. Continuous genomic investigations need to be conducted to accurately depict the status of colistin resistance in clinical settings.

Intradermal Immunization with Heat-Killed Klebsiella pneumoniae Leading to the Production of Protective Immunoglobulin G in BALB/c Mice

Introduction:

Klebsiella pneumoniae superbug is emerging as a serious health concern as resistance to last-resort antibiotics spreads. To bypass the therapeutic molecules used today, the development of an immunoprophylactic safe approach is of great clinical relevance. This study was conducted to determine the protective efficacy of antibodies elicited by killed vaccine against multidrug-resistant (MDR) K. pneumoniae.

Materials and Methods:

In this study, heat-killed MDR K. pneumoniae isolated from different clinical samples were employed for the intradermal immunization of 10 BALB/c mice. Two weeks after the third dose of immunization, the mice were intraperitoneally challenged with live K. pneumoniae and observed for 14 days. Tail blood was collected 7 days after each booster followed by cardiac puncture 14 days postchallenge. Bactericidal activity and antigen-binding capacity of the serum antibody produced by the vaccine were evaluated by serum bactericidal antibody (SBA) assay and ELISA, respectively.

Results:

In this study, 80% survival rates were observed at 14 days postchallenge among the immunized mice. Regarding SBA assay, 100% bactericidal activity of the immunized mouse sera was observed using 50% guinea pig complement at 1:10 serum dilution after 3 h of incubation, and all the pre- and postchallenge immunized serum immunoglobulin G antibody had significantly higher optical density values comparing the control mice in ELISA.

Conclusion:

In our study, intradermal immunization with heat-killed MDR K. pneumoniae produced protective antibodies in BALB/c mice. These findings suggest that the use of a first-generation vaccine provides the supply of a larger number of candidate antigens for eliciting required immune response.

Co-existence of NDM-1 and OXA-48 genes in Carbapenem Resistant Klebsiella pneumoniae clinical isolates in Kafrelsheikh, Egypt

Background

The noteworthy spread of carbapenem-resistant K. pneumoniae (CR-KP) isolates represents a significant safety threat.

Objective

Determination of the carbapenemase genes incidence among CR-KP clinical isolates in Kafrelsheikh, Egypt.

Methods

A total of 230 K. pneumoniae isolates were recovered from four hospitals in Kafrelsheikh, Egypt. Susceptibility testing was conducted using Kirby-Bauer method and automated-Vitek2 system. CR-KP isolates were tested using modified Hodge test (MHT) and combined disk synergy test. PCR and DNA sequencing were conducted for CR-KP isolates to recognize the included carbapenemase-genes.

Results

Out of 230 K. pneumoniae isolates, 50 isolates presented resistance to carbapenem (meropenem). All 50 CR-KP isolates were multidrug-resistant (MDR). Genes like blaNDM-1 and blaOXA-48 were the only detected genes among CR-KP with an incidence of 70.0% and 52.0%, respectively. Up to 74.0% of the tested isolates carried at least one of the two recorded genes, among them 48.0% co-harbored both blaNDM-1 and blaOXA-48 genes. The accession-numbers of sequenced blaNDM-1 and blaOXA-48 genes were MG594615 and MG594616, respectively.

Conclusion

This study reported a high incidence of MDR profile with the emergence of blaNDM-1 and blaOXA-48 genes co-existence in CR-KP isolates in Kafrelsheikh, Egypt. Hence, more restrictions should be applied against the spread of such serious pathogens.

Landscape of Multidrug-Resistant Gram-Negative Infections in Egypt: Survey and Literature Review

Purpose

This article is the first to review published reports on the prevalence of multidrug-resistant (MDR) gram-negative infections in Egypt and gain insights into antimicrobial resistance (AMR) surveillance and susceptibility testing capabilities of Egyptian medical centers.

Materials and Methods

A literature review and online survey were conducted.

Results

The online survey and literature review reported high prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (19–85.24% of E. coli, and 10–87% of K. pneumoniae), carbapenem-resistant Enterobacteriaceae (35–100% of K. pneumoniae and 13.8–100% of E. coli), carbapenem-resistant Acinetobacter baumannii (10–100%), and carbapenem-resistant Pseudomonas aeruginosa (15–70%) in Egypt. Risk factors for MDR Gram-negative infections were ventilated patients (67.4%), prolonged hospitalization (53.5%) and chronic disease (34.9%). Although antimicrobial surveillance capabilities were deemed at least moderate in most centers, lack of access to rapid AMR diagnostics, lack of use of local epidemiological data in treatment decision-making, lack of antimicrobial stewardship (AMS) programs, and lack of risk prediction tools were commonly reported by respondents.

Conclusion

This survey has highlighted the presence of knowledge gaps as well as limitations in the surveillance and monitoring capabilities of AMR in Egypt, with most laboratories lacking rapid diagnostics and molecular testing. Future efforts in Egypt should focus on tackling these issues via nationwide initiatives, including understanding the AMR trends in the country, capacity building of laboratories and their staff to correctly and timely identify AMR, and introducing newer antimicrobials for targeting emerging resistance mechanisms in Gram-negative species.

β-lactam resistance associated with β-lactamase production and porin alteration in clinical isolates of E. coli and K. pneumoniae

β-lactam resistance represents a worldwide problem and a serious challenge for antimicrobial treatment. Hence this research was conducted to recognize several mechanisms mediating β-lactam resistance in E. coli and K. pneumoniae clinical isolates collected from Mansoura University hospitals, Egypt. A total of 80 isolates, 45 E. coli and 35 K. pneumoniae isolates, were collected and their antibiotic susceptibility was determined by the Disc diffusion method followed by phenotypic and genotypic detection of extended-spectrum β-lactamases (ESBLs), AmpC β-lactamase, carbapenemase enzymes. The outer membrane protein porins of all isolates were analyzed and their genes were examined using gene amplification and sequencing. Also, the resistance to complement-mediated serum killing was estimated. A significant percentage of isolates (93.8%) were multidrug resistance and showed an elevated resistance to β-lactam antibiotics. The presence of either ESBL or AmpC enzymes was high among isolates (83.75%). Also, 60% of the isolated strains were carbapenemase producers. The most frequently detected gene of ESBL among all tested isolates was bla_CTX-M-15 (86.3%) followed by bla_TEM-1 (81.3%) and bla_SHV-1 (35%) while the Amp-C gene was present in 83.75%. For carbapenemase-producing isolates, bla_NDM1 was the most common (60%) followed by bla_VIM-1 (35%) and bla_OXA-48 (13.8%). Besides, 73.3% and 40% of E. coli and K. pneumoniae isolates respectively were serum resistant. Outer membrane protein analysis showed that 93.3% of E. coli and 95.7% of K. pneumoniae isolates lost their porins or showed modified porins. Furthermore, sequence analysis of tested porin genes in some isolates revealed the presence of frameshift mutations that produced truncated proteins of smaller size. β-lactam resistance in K. pneumoniae and E. coli isolates in our hospitals is due to a combination of β-lactamase activity and porin loss/alteration. Hence more restrictions should be applied on β-lactams usage to decrease the emergence of resistant strains.

Gambogic acid protects LPS-induced apoptosis and inflammation in a cell model of neonatal pneumonia through the regulation of TrkA/Akt signaling pathway

Objective

In this work, we investigated the effects of gambogic acid (GA) on lipopolysaccharide (LPS)-induced apoptosis and inflammation in a cell model of neonatal pneumonia.

Method

Human WI-38 cells were maintained in vitro and incubated with various concentrations of GA to examine WI-38 survival. GA-preincubated WI-38 cells were then treated with LPS to investigate the protective effects of GA on LPS-induced death, apoptosis and inflammation. Western blot assay was utilized to analyze the effect of GA on tropomyosin receptor kinase A (TrkA) signaling pathway in LPS-treated WI-38 cells. In addition, human AKT serine/threonine kinase 1 (Akt) gene was knocked down in WI-38 cells to further investigate the associated genetic mechanisms of GA in protecting LPS-induced inflammation and apoptosis.

Results

Pre-incubating WI-38 cells with low and medium concentrations GA protected LPS-induced cell death, apoptosis and inflammatory protein productions of IL-6 and MCP-1. Using western blot assay, it was demonstrated that GA promoted TrkA phosphorylation and Akt activation in LPS-treated WI-38 cells. Knocking down Akt gene in WI-38 cells showed that GA-associated protections against LPS-induced apoptosis and inflammation were significantly reduced.

Conclusions

GA protected LPS-induced apoptosis and inflammation, possibly through the activations of TrkA and Akt signaling pathway. This work may broaden our understanding on the molecular mechanisms of human neonatal pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40360-021-00496-9.

Detection of harmful foodborne pathogens in food samples at the points of sale by MALDT-TOF MS in Egypt

OBJECTIVES

Microbes can contaminate foodstuffs resulting in foodborne illnesses. Investigating microbial hazards in foods at the point of sale with rapid tools is required to avoid foodborne illness outbreaks. The current study aimed to identify the microbial hazards in food samples collected from retail shops at sale points using MALDI-TOF MS.

RESULTS

Food samples were collected from stores and supermarkets in four Delta cities (Tanta, Kutour, Kafr-Elzayat and Benha). Analysis of 178 samples of fish, meat and dairy products revealed 20 different bacterial species. 44.76% of isolates were identified as E. coli, 17.44% were identified as Enterobacter spp., and E. cloacae was predominant. 12.2% were identified as Citrobacter spp., and C. braakii was predominant, and 8.7% were identified as Klebsiella spp., and K. pneumoniae was predominant. Moreover, eight Proteus mirabilis, six Morganella morganii, five Staphylococcus hominis, three Serratia marcescens, two Pseudomonas aeruginosa, one Salmonella typhimurium and one Enterococcus faecalis were detected. Foodstuffs not only be contaminated during production and processing but also during storage and transport. Identification of harmful human pathogens in foodstuffs is alarming and consider threatening to public health. Identification of microbiological hazards in foods using MALDI-TOF MS provides an efficient tool for identifying foodborne pathogens.

Changes of Gut-Microbiota-Liver Axis in Hepatitis C Virus Infection

Simple Summary

Gut microbiota alteration is linked to many health disorders including hepatitis C virus (HCV) infection. This dysbiosis in turn impacts the coordination between the gut and the liver that is known as the gut–liver-axis. Here, we discuss the latest findings regarding the changes in gut microbiota structure and functionality post HCV infection and its treatment regimens. In addition, we underline the contribution of the microbiota alterations to HCV associated liver complications.

Abstract

The gut–liver-axis is a bidirectional coordination between the gut, including microbial residents, the gut microbiota, from one side and the liver on the other side. Any disturbance in this crosstalk may lead to a disease status that impacts the functionality of both the gut and the liver. A major cause of liver disorders is hepatitis C virus (HCV) infection that has been illustrated to be associated with gut microbiota dysbiosis at different stages of the disease progression. This dysbiosis may start a cycle of inflammation and metabolic disturbance that impacts the gut and liver health and contributes to the disease progression. This review discusses the latest literature addressing this interplay between the gut microbiota and the liver in HCV infection from both directions. Additionally, we highlight the contribution of gut microbiota to the metabolism of antivirals used in HCV treatment regimens and the impact of these medications on the microbiota composition. This review sheds light on the potential of the gut microbiota manipulation as an alternative therapeutic approach to control the liver complications post HCV infection.

In vitro synergistic activity of fosfomycin in combination with other antimicrobial agents against carbapenem-resistant Klebsiella pneumoniae isolated from patients in a hospital in Thailand

INTRODUCTION

Carbapenem-resistant Klebsiella pneumoniae (CRKP) causes high morbidity and mortality worldwide. The purpose of the study was to assess the synergistic activity of fosfomycin in combination with other antimicrobial agents against CRKP isolated from patients in Songklanagarind Hospital, Thailand.

METHODS

A total of 35 K. pneumoniae isolates were obtained from patients in Songklanagarind Hospital. The MICs of imipenem and meropenem were determined in all isolates by broth microdilution. In all CRKP isolates, the presence of carbapenemase and extended-spectrum β-lactamase (ESBL) genes was investigated by PCR, while the production of these enzymes was determined by combined disk test. In the carbapenemase-genes-negative CRKP isolates, the porin loss and efflux pump were characterized by SDS-PAGE and broth microdilution, respectively. Finally, the synergistic effects of fosfomycin and other antimicrobial agents were evaluated by checkerboard analysis.

RESULTS

Twenty-one of 35 K. pneumoniae isolates were classified as CRKP. Most of CRKP isolates carried bla_NDM-1 (n = 18), bla_SHV (n = 21), bla_CTX-M (n = 21), and bla_TEM (n = 16). In fosfomycin-based combination, the result showed that the highest synergistic activity in this study was observed in the combination of fosfomycin and gentamicin (61.9%).

CONCLUSION

These findings suggested that the fosfomycin and gentamicin combination might be useful as a possible treatment option for CRKP infection.

Characterization of β-lactam resistance in K. pneumoniae associated with ready-to-eat processed meat in Egypt

K. pneumoniae was known as a nosocomial infection that causes human diseases. It is considered as one of the food-borne pathogens as it causes septicemia and diarrhea in humans. This study aims to characterize K. pneumoniae strains isolated from ready to eat processed meat phenotypically and genetically. Three hundred and fifty ready to eat processed meat (Luncheon-meat) samples were collected. Forty-four (12.6%) K. pneumoniae strains were isolated and bio-typed, where the majority were identified to belong to biotype B1. K1 and K2 serotypes were detected and strains were classified as hypermucoviscous K. pneumoniae (HVKP) and classic K. pneumoniae (CKP) (26 and 18 isolates, respectively). The isolates were resistant to several classes of β–lactam antibiotics, ceftazidim and cefotaxime (95.5%), cefoxitin (93.2%), ertapenem (90.9%) and amoxicillin-clavulanic acid (86.4%). They were classified as extended spectrum β–lactamases (ESBLs), AmpC or carbapenemase-producers phenotypically. Eighteen β-lactamase genes were investigated by PCR. The most prominent genes were SHV (63.6%), TEM (52.2%), CTX-M15 (50%), AMPC (47.7%), CIT-M (45.5%) and VIM (43.2%). Co-detection of β–lactam resistance genes revealed 42 gene profiles. Twenty-four isolates had the complete efflux system (AcrAB-ToƖC). Besides, Integrons (I, II, III) were detected in 20 isolates. Molecular typing by ERIC-PCR showed high genetic diversity between isolates as 34 different patterns were identified. Overall, this study confirmed the hazards posed by the presence of multiple resistance genes in the same isolate and this should not be undervalued. Besides, the horizontal transfer of plasmid harboring resistance genes between isolates in food represents potential health risks for consumers in Egypt and so the control and inhibition plans are necessary.

Circulation of emerging NDM-5-producing Escherichia coli among humans and dogs in Egypt

The emergence of NDM-producing Escherichia coli has considerably threatened human and animal health worldwide. This study describes for the first time in Egypt, the draft genome sequences of emerging NDM-5-producing E. coli from humans and dogs, and investigates genetic relatedness between isolates from both sources. Two E. coli from human urine and seven from environmental clinical samples of dogs exhibited resistance to carbapenems and harbouring bla_NDM were subjected to Illumina Miseq whole-genome sequencing (WGS). Assembly and analysis of the reads were performed to identify resistance genes, multilocus sequence types (MLST), plasmid replicon types (Inc) and insertion sequences (IS) of the bla_NDM region; core genome MLST (cgMLST) analysis was also performed. Two different NDM alleles were identified; bla_NDM-5 in E. coli HR119 from the urine of a healthy person and environmental samples of dogs, and bla_NDM-1 in E. coli HR135 from a human patient's urine. Multiple mobilizable resistance genes to different antimicrobial classes were identified except the colistin resistance gene, mcr. E. coli isolates from humans and dogs were assigned to different sequence types (STs). Using cgMLST, dog isolates clustered together with only 1-2 allellic differences; however, human E. coli showed 1,978 different allelles compared with dog isolates. Plasmidfinder results indicated the presence of an IncX3 replicon in bla_NDM-5 -producing E. coli; however, bla_NDM-1 was linked to IncCoIKP3. Notably, the NDM region (3 Kb) in all isolates from humans and dogs was highly similar with variable flanking sequences that represented different IS elements. This study reports the first emergence of NDM-5-producing E. coli from dogs in Egypt that shared some genetic features with human isolates and could be considered potential public health threats.

Understanding the Epidemiology of Multi-Drug Resistant Gram-Negative Bacilli in the Middle East Using a One Health Approach

In the last decade, extended-spectrum cephalosporin and carbapenem resistant Gram-negative bacilli (GNB) have been extensively reported in the literature as being disseminated in humans but also in animals and the environment. These resistant organisms often cause treatment challenges due to their wide spectrum of antibiotic resistance. With the emergence of colistin resistance in animals and its subsequent detection in humans, the situation has worsened. Several studies reported the transmission of resistant organisms from animals to humans. Studies from the middle east highlight the spread of resistant organisms in hospitals and to a lesser extent in livestock and the environment. In view of the recent socio-economical conflicts that these countries are facing in addition to the constant population mobilization; we attempt in this review to highlight the gaps of the prevalence of resistance, antibiotic consumption reports, infection control measures and other risk factors contributing in particular to the spread of resistance in these countries. In hospitals, carbapenemases producers appear to be dominant. In contrast, extended spectrum beta lactamases (ESBL) and colistin resistance are becoming a serious problem in animals. This is mainly due to the continuous use of colistin in veterinary medicine even though it is now abandoned in the human sphere. In the environment, despite the small number of reports, ESBL and carbapenemases producers were both detected. This highlights the importance of the latter as a bridge between humans and animals in the transmission chain. In this review, we note that in the majority of the Middle Eastern area, little is known about the level of antibiotic consumption especially in the community and animal farms. Furthermore, some countries are currently facing issues with immigrants, poverty and poor living conditions which has been imposed by the civil war crisis. This all greatly facilitates the dissemination of resistance in all environments. In the one health concept, this work re-emphasizes the need to have global intervention measures to avoid dissemination of antibiotic resistance in humans, animals and the environment in Middle Eastern countries.

A Study of the Virulence Traits of Carbapenem-Resistant Klebsiella pneumoniae Isolates in a Galleria mellonella Model

The increasing incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) strains is considered as a terrifying public health concern. This study target was to gain a further insight into the virulence traits of CRKP isolates in Egypt. The study was carried out by using 43 clinical K. pneumoniae isolates. Antibiotic susceptibility testing, biofilm formation assay, and molecular characterization of carbapenemase and virulence genes were done for all isolates. In addition, the genotypic relationship between CRKP isolates was identified by using enterobacterial repetitive intergenic consensus-polymerase chain reactions (ERIC-PCRs). A Galleria mellonella survival assay was adopted for in vivo testing of virulence of the CRKP. Carbapenem resistance was exhibited among 58% (25/43) isolates. Minimum inhibitory concentration values of carbapenem-resistant K. pneumoniae (CRKP) ranged from 32 to 128 μg/mL. Biofilm assay has revealed that 21 isolates (49%) had moderate biofilm formation and 11 isolates (25.5%) were strong biofilm producers. Bla_NDM-1 was recognized in 20.9% (9/43) of the isolates, while bla_OXA-48 was observed in 18.5% (8/43). Type 3 fimbriae (mrkD) and entB were addressed among 72.1% and 62.8% of K. pneumoniae isolates, respectively. The ybtS and iutA genes were detected among 44.2% and 37.2% of the isolates, respectively. ERIC-PCR showed 23 genetic profiles among CRKP isolates. CRKP biofilm producers were virulent according to the G. mellonella model, which indicates the importance of biofilm as a virulence trait among CRKP. This study indicates the emergence of CRKP with increased virulence traits, especially biofilm formation, in Egypt. This alarming report highlights the ongoing need for effective screening procedures and strict infection control measures.

Identification, molecular characterization, and structural analysis of the blaNDM-1 gene/enzyme from NDM-1-producing Klebsiella pneumoniae isolates

NDM-1 comprises a carbapenemase that was first detected in 2008 in New Delhi, India. Since then, NDM-1-producing Klebsiella pneumoniae strains have been reported in many countries and usually associated with intra and inter-hospital dissemination, along with travel-related epidemiological links. In South America, Brazil represents the largest reservoir of NMD-1-producing K. pneumoniae. Here, we focused on the detection and molecular/structural characterization of the bla_NDM-1 resistance gene/enzyme from 24 K. pneumoniae clinical isolates in the Midwest region of Brazil. Antimicrobial susceptibility assays showed that all isolates are resistant to carbapenems. Molecular typing of the isolates revealed seven clonal groups among the K. pneumoniae isolates, which may indicate intra or inter-hospital dissemination. Moreover, the bla_NDM-1 gene was detected in all 24 K. pneumoniae isolates and the full bla_NDM-1 gene was cloned. Bioinformatics analysis showed that the NDM-1 enzyme sequence found in our isolates is highly conserved when compared to other NDM-1 enzymes. In addition, molecular docking studies indicate that the NDM-1 identified binds to different carbapenems through hydrogen and zinc coordination bonds. In summary, we present the molecular characterization of NDM-1-producing K. pneumoniae strains isolated from different hospitals, also providing atomic level insights into molecular complexes NDM-1/carbapenem antibiotics.

Prevalence and Mechanisms of Carbapenem Resistance Among Acinetobacter baumannii Clinical Isolates in Egypt

The increasing number of carbapenem-resistant Acinetobacter baumannii clinical isolates is a major concern, which restricts therapeutic options for treatment of serious infections caused by this emerging pathogen. The aim of this work is to assess the antimicrobial resistance profile and identify the molecular mechanisms involved in carbapenem resistance in A. baumannii isolated from different clinical sources in Mansoura University Hospitals, Egypt. Antimicrobial susceptibility testing has shown that resistance to carbapenem has dramatically increased (98%) with concomitant elevated levels of resistance to quinolones, trimethoprim/sulfamethoxazole, and aminoglycosides. Polymyxin B and colistin are considered the last resort. Random amplified polymorphic DNA (RAPD) typing method revealed great diversity among A. baumannii isolates. Coexistence of diverse intrinsic and acquired carbapenem-hydrolyzing β-lactamases has been detected in the tested isolates: Ambler class A: bla_KPC (56%) and bla_GES (48%), and Ambler class B: bla_NDM (30%), bla_SIM (28%), bla_VIM (20%), and bla_IMP (10%). Most isolates (94%) carried bla_OXA-23-like and bla_OXA-51-like simultaneously. bla_OXA-23-like was preceded by ISAba1 providing a potent promoter activity for its expression. Sequencing analysis revealed that ISAba1 has been also inserted in carbapenem resistance-associated outer membrane protein (OMP) (carO) gene in three isolates, two of which were clonal based on RAPD typing, leading to interruption of its expression as confirmed by SDS-PAGE analysis of OMP fractions. Carbapenem resistance genes are widely distributed among A. baumannii clinical isolates from different clinical sources. Therefore, enhanced infection control measures, effective barriers, and rational use of antimicrobials should be enforced in hospitals for minimizing the widespread resistance to carbapenems and all other antibiotics.

Cystatins 9 and C as a Novel Immunotherapy Treatment That Protects against Multidrug-Resistant New Delhi Metallo-Beta-Lactamase-1-Producing Klebsiella pneumoniae

Multidrug-resistant (MDR) bacterial pneumonia can induce dysregulated pulmonary and systemic inflammation leading to morbidity and mortality. Antibiotics to treat MDR pathogens do not function to modulate the extent and intensity of inflammation and can have serious side effects. Here we evaluate the efficacy of two human cysteine proteinase inhibitors, cystatin 9 (CST9) and cystatin C (CSTC), as a novel immunotherapeutic treatment to combat MDR New Delhi metallo-beta-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae. Our results showed that mice infected intranasally (i.n.) with a 90% lethal dose (LD₉₀) challenge of NDM-1 K. pneumoniae and then treated with the combination of human recombinant CST9 (rCST9) and rCSTC (rCSTs; 50 pg of each i.n. at 1 h postinfection [p.i.] and/or 500 pg of each intraperitoneally [i.p.] at 3 days p.i.) had significantly improved survival compared to that of infected mice alone or infected mice treated with individual rCSTs (P < 0.05). Results showed that both of our optimal rCST treatment regimens modulated pulmonary and systemic proinflammatory cytokine secretion in the serum, lungs, liver, and spleen in infected mice (P < 0.05). Treatment also significantly decreased the bacterial burden (P < 0.05) while preserving lung integrity, with reduced inflammatory cell accumulation compared to that in infected mice. Further, rCST treatment regimens reduced lipid peroxidation and cell apoptosis in the lungs of infected mice. Additionally, in vitro studies showed that rCSTs (50 or 500 pg of each) directly decreased the viability of NDM-1 K. pneumoniae. In conclusion, the data showed that rCST9/rCSTC worked synergistically to modulate host inflammation against MDR NDM-1 K. pneumoniae pneumonia, which significantly improved survival. Therefore, rCST9/rCSTC is a promising therapeutic candidate for the treatment of bacterial pneumonia.