EXTENDED-SPECTRUM BETA-LACTAMASE PRODUCING GRAM NEGATIVE BACTERIA IN IRAN: A REVIEW

Antibiotic susceptibility patterns at the Médecins Sans Frontières (MSF) Acute Trauma Hospital in Aden, Yemen: a retrospective study from January 2018 to June 2021

Background

Antimicrobial resistance (AMR) is an urgent global health concern, especially in countries facing instability or conflicts, with compromised healthcare systems. Médecins Sans Frontières (MSF) established an acute trauma hospital in Aden, Yemen, treating mainly war-wounded civilians, and implemented an antimicrobial stewardship (AMS) programme. This study aimed to describe clinical characteristics and identify antibiotic susceptibility patterns representative of patients treated with antibiotics.

Methods

Retrospective cross-sectional study using routinely collected data from all patients treated with antibiotics in the MSF-Aden Acute Trauma hospital between January 2018 and June 2021. Routine clinical data from patients' files was entered into an AMS electronic database and microbiological data were entered into WHONET. Both databases were imported and merged in REDCap and analysed using RStudio.

Results

Three hundred and sixty-three of 481 (75%) included patients were injured by violence-related trauma. Most were men aged 19-45 years (n = 331; 68.8%). In total, 598 infections were diagnosed and treated. MDR organisms were identified in 362 (60.5%) infections in 311 (65%) patients. Skin and soft-tissue infections (SSTIs) (n = 143; 24%) were the most common, followed by osteomyelitis (n = 125; 21%) and intra-abdominal-infections (IAIs) (n = 116; 19%), and 111 (19%) secondary bloodstream infections were identified. Escherichia coli was the most frequently identified pathogen, causing IAI (n = 87; 28%) and SSTI (n = 43; 16%), while Staphylococcus aureus caused mainly osteomyelitis (n = 84; 19%). Most Gram-negatives were ESBL producers, including E. coli (n = 193; 81.4%), Klebsiella pneumoniae (n = 72; 77.4%) and Enterobacter cloacae (n = 39; 50%) while most S. aureus were methicillin resistant (n = 93; 72.6%).

Conclusions

High rates of MDR were found. This information will facilitate a comprehensive review of the empirical antibiotic treatment guidelines.

Predominance of Multidrug-Resistant Gram-Negative Bacteria on Contaminated Surfaces at a Tertiary Hospital in Tanzania: A Call to Strengthening Environmental Infection Prevention and Control Measures

The spreading of multidrug resistance (MDR) strains in the hospital settings via contaminated surfaces have been increasingly reported where Gram-negative bacteria have been implicated in causing most nosocomial infections. This study aimed to determine the rate of contamination with multi-resistant gram-negative bacteria in the hospital environment. A cross-sectional study was conducted at Muhimbili National Hospital paediatric department, between July and August 2020. Non-repetitive surface swab samples were collected from predefined surfaces and medical device surfaces, and cultured on MacConkey agar with and without antibiotics. Isolates were identified using biochemical test and tested for antibiotic susceptibility using the Kirby-Bauer disk diffusion method. The rate of hospital contamination with Gram-negative bacteria across the Pediatrics units was 30%, with a high rate observed in oncology units (34.8%) and the malnutrition/diarrhoea ward (32.1%). Sink/washing basin had the highest frequency of bacterial contamination (74.2%). We observed a high rate of ESBL (32.5%), with Acinetobacter baumannii, Klebsiella pneumoniae, and E. coli being the predominant ESBL-producing Gram-negative bacteria, while carbapenemase-producing Gram-negative bacteria was detected at 22.8%. Highest resistance rates (63-100%) were observed against ceftriaxone and trimethoprim-sulfamethoxazole. Up to 51% of the Gram-negative bacteria showed resistant to meropenem. MDR strains were detected in 61.4% of Gram-negative bacteria isolated. In conclusion, we observed a high rate of MDR bacteria contaminating hospital surfaces. The higher rate of MDR calls for a need to strengthen infectious prevention control measures, including cleaning practices in the hospital environment, to reduce the risk of transmission of resistant strains to patients and healthcare workers.

Beta-lactam resistance and the effectiveness of antimicrobial peptides against KPC-producing bacteria

Bacterial resistance is a problem that is giving serious cause for concern because bacterial strains such as Acinetobacter baumannii and Pseudomonas aeruginosa are difficult to treat and highly opportunistic. These bacteria easily acquire resistance genes even from other species, which confers greater persistence and tolerance towards conventional antibiotics. These bacteria have the highest death rate in hospitalized intensive care patients, so strong measures must be taken. In this review, we focus on the use of antimicrobial peptides (AMPs) as an alternative to traditional drugs, due to their rapid action and lower risk of generating resistance by microorganisms. We also present an overview of beta-lactams and explicitly explain the activity of AMPs against carbapenemase-producing bacteria as potential alternative agents for infection control.

Mutations in AR or SRD5A2 Genes: Clinical Findings, Endocrine Pitfalls, and Genetic Features of Children with 46,XY DSD

OBJECTIVE

Androgen insensivity syndrome (AIS) and 5α-reductase deficiency (5α-RD) present with indistinguishable phenotypes among the 46,XY disorders of sexual development (DSD) that usually necessitate molecular analyses for the definitive diagnosis in the prepubertal period. The aim was to evaluate the clinical, hormonal and genetic findings of 46,XY DSD patients who were diagnosed as AIS or 5α-RD.

METHODS

Patients diagnosed as AIS or 5α-RD according to clinical and hormonal evaluations were investigated. Sequence variants of steroid 5-α-reductase type 2 were analyzed in cases with testosterone/dihydrotestosterone (T/DHT) ratio of ≥20, whereas the androgen receptor (AR) gene was screened when the ratio was <20. Stepwise analysis of other associated genes were screened in cases with no causative variant found in initial analysis. For statistical comparisons, the group was divided into three main groups and subgroups according to their genetic diagnosis and T/DHT ratios.

RESULTS

A total of 128 DSD patients from 125 non-related families were enrolled. Birth weight SDS and gestational weeks were significantly higher in 5α-RD group than in AIS and undiagnosed groups. Completely female phenotype was higher in all subgroups of both AIS and 5α-RD patients than in the undiagnosed subgroups. In those patients with stimulated T/DHT <20 in the prepubertal period, stimulated T/DHT ratio was significantly lower in AIS than in the undiagnosed group, and higher in 5α-RD. Phenotype associated variants were detected in 24% (n=18 AIS, n=14 5α-RD) of the patients, revealing four novel AR variants (c.94G>T, p.Glu32*, c.330G>C, p.Leu110=; c.2084C>T, p.Pro695Leu, c.2585_2592delAGCTCCTG, p.(Lys862Argfs*16), of these c.330G>C with silent status remained undefined in terms of its causative effects.

CONCLUSION

T/DHT ratio is an important hormonal criterion, but in some cases, T/DHT ratio may lead to diagnostic confusion. Molecular diagnosis is important for the robust diagnosis of 46,XY DSD patients. Four novel AR variants were identified in our study.

Antibiotic-resistant pathogenic bacterial isolates from patients attending the outpatient department of university of Cape Coast hospital, Ghana: A retrospective study between 2013-2015

Uropathogenic Escherichia coli (E. coli) is an important urinary tract infection (UTI) that has been associated with both complicated and uncomplicated disease conditions. The global emergence of multiple drug-resistant (MDR) and extended-spectrum β-lactamase (ESBL) is of public health concern as the resistance limits the current treatment options. The objective of this study was to analyze the antibiotic-resistant patterns among the uropathogenic E. coli isolates at the University of Cape Coast (UCC) hospital between 2013 and 2015 as baseline data to understand the current antibiotic resistance situation within UCC and its environs. A retrospective cross-sectional study of bacteria isolates at UCC hospital from January 2013 to December 2015 were analyzed. A standard biochemical and antibiotic susceptibility tests were performed using Kirby-Bauer NCCLs modified disc diffusion technique. The network of interaction between pathogenic isolates and antibiotic resistance was performed using Cytoscape software. Statistical significance was tested using ANOVA and one-sample Wilcoxon test. The overall E. coli prevalence was 15.76% (32/203); females had the highest infection of 17.33% (26/150) compared to male subjects who had 11.32% (6/53) out of all the pathogenic infections. The E. coli prevalence among the age categories were 2/21 (9.52%), 27/154 (17.53%) and 4/21 (19.05%) among ≤20 years, 21-40 years and 41-60 years respectively. The isolated resistant pathogens exhibited different antibiotic resistance patterns. An interaction network of nodes connecting to other nodes indicating positive correlations between the pathogens and antibiotic resistance was established. Escherichia coli, Citrobacter spp, Klebsiella spp among other isolated pathogens formed higher centrality in the network of interaction with antibiotic resistance. The individual E. coli isolates showed a significant difference in the mean ± SD (95% CI) pattern of antibiotic resistance, 2.409±1.205 (1.828-2.990), χ2 = 36.68, p<0.0001. In conclusion, the study reports the interaction of E. coli isolates at UCC hospital and its antibiotic-resistant status between 2013 and 2015. This data forms the baseline information for assessing the current antibiotic status in UCC and its environs.

Extended Spectrum Beta-Lactamase (ESBL) Produced by Gram-Negative Bacteria in Trinidad and Tobago

Gram-negative bacterial infections are a global health problem. The production of beta-lactamase is still the most vital factor leading to beta-lactam resistance. In Trinidad and Tobago, extended spectrum beta-lactamase (ESBL) production has been detected and reported mainly in the isolates of Klebsiella pneumoniae and Escherichia coli and constitutes a public health emergency that causes high morbidity and mortality in some patients. In this literature review, the authors cover vast information on ESBL frequency and laboratory detection using both conventional and molecular methods from clinical data. The aim is to make the reader reflect on how the actual knowledge can be used for rapid detection and understanding of the spread of antimicrobial resistance problems stemming from ESBL production among common Gram-negative organisms in the health care system.

The magnitude of extended-spectrum beta-lactamase- producing Enterobacteriaceae from clinical samples in Ethiopia: a systematic review and meta-analysis

BACKGROUND

The rapid spread of resistance among extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is a serious problem around the world. It results in serious clinical complications in humans and has become a global threat. Therefore, this systematic review and meta-analysis was aimed to estimate the pooled prevalence of ESBL-producing Enterobacteriaceae in different clinical samples in Ethiopia.

METHODS

A systematic search was conducted on PubMed, Web of Science, Embase, Google Scholar and the Cochrane Library. All identified observational studies reporting the prevalence of ESBL-producing Enterobacteriaceae from clinical samples in Ethiopia were included. Four authors independently extracted data and analysed using R software version 3.6.1 and STATA statistical software version 13. A random-effects model was computed to estimate the pooled prevalence of ESBL-producing Enterobacteriaceae in Ethiopia.

RESULTS

Of 142 articles reviewed, 14 studies that fulfilled the inclusion criteria were included in the meta-analysis. The pooled prevalence of ESBL-producing Enterobacteriaceae in the different clinical specimens in Ethiopia was 49 % (95 % CI: 39, 60). Klebsiella pneumoniae was the leading ESBL-producing Enterobacteriaceae followed by Escherichia coli and Acinetobacter baumannii with a prevalence of 74, 67 and 60 %, respectively. ESBL-producing isolates showed a high rate of resistance to cefotaxime, ceftriaxone, ceftazidime, Amoxicillin clavulanic acid (AMC), ampicillin and aztreonam. The better options for the treatment of ESBL-producing Enterobacteriaceae are amikacin and Imipenem.

CONCLUSION

The magnitude of ESBL-producing Enterobacteriaceae in different clinical samples in Ethiopia is alarmingly high and represents a threat to human health. Hence, a coordinated effort needs to be implemented for the prevention and control of these Enterobacteriaceae .

Expression of RND efflux pumps mediated antibiotic resistance in Pseudomonas aeruginosa clinical strains

Resistance-Nodulation-Division (RND) efflux pumps are responsible for multidrug resistance in Pseudomonas aeruginosa. The present study aimed to evaluate the overexpression of RND efflux pumps and its role in the antibiotic resistance of P. aeruginosa clinical isolates. A number of 122 isolates were obtained from three military hospitals in Tehran, Iran. In order to determine the antibiotic resistance, the isolates were identified and assessed by the disk diffusion and agar dilution methods. This study investigated the gene expression of four multi-drug efflux pump systems (MexAB-OprM, MexCD-OprJ, MexEF-OprN and MexXY (-OprA)) and its correlation with antibiotic resistance. The isolates indicated that the highest resistance rate was against ticarcillin (80%), followed by ciprofloxacin (74%) and meropenem (71%). Most of them expressed mexB (69%), mexC (28.7%), mexE (43.4%), and mexY (74.6%), suggesting that mexB and mexY were highly expressed in the studied strains. The overexpression of mexB and mexY was significantly more prevalent in the ICU wards (p = 0.033). Furthermore, there was a significant correlation between the expression of RND-type efflux pumps and the resistance to most anti-pseudomonal antibiotics.

Levofloxacin versus ceftriaxone for treatment of acute pyelonephritis in Iranian adults

INTRODUCTION

Acute pyelonephritis is among the most common bacterial infections. Options for initial treatment of pyelonephritis include an extended-spectrum cephalosporin or a fluoroquinolone. In this study, we aimed to compare the clinical outcomes of patients receiving ceftriaxone to those who received levofloxacin for the treatment of acute pyelone-phritis.

METHODS

In this randomized, open-label trial, hospitalized adults with acute pyelonephritis were treated with ceftriaxone (1g IV every 12 hours) or levofloxacin (750 mg IV daily) for at least 7 days. Clinical and microbiological characteristics were compared among patients treated with ceftriaxone and levofloxacin.

RESULTS

A total of 59 patients were randomized, 30 to the ceftriaxone group and 29 to the levofloxacin group. The clinical response for 68.0% of patients in the ceftriaxone group and 56.0% of patients in the levofloxacin group were cured. The mi-crobiological response (pathogen eradication rates) was 68.7% in the ceftriaxone group and 21.4% in the levofloxacin group.(P value=0.00028) Escherichia coliwas the most common pathogen (n = 31), followed by Klebsiella pneumoniae(n = 21). High resistance rates were detected for cotrimoxazole (55%), ciprofloxacin (48%), and ceftriaxone (34.4%) in isolat-ed E.coli. Likewise, all K. pneumoniaeisolates were resistant to ciprofloxacin.

CONCLUSIONS

Our study indicates that ceftriaxone was more effective than levofloxacin in the treatment of acute pyelone-phritis, on the basis of microbiological response, but there were no statistically significant differences between the treatment groups in the rates of clinical cure.The resistance of uropathogens to the most used antibiotics was relatively high. Choosing the treatment regimen based on susceptibility testing results and shortening the duration of the therapy are now recommend-ed to be the most important approaches to decrease the spread of antibiotic resistance worldwide.

Resistance pattern of Escherichia coli to levofloxacin in Iran: a narrative review

Fluoroquinolones (FQs) are widely used in the treatment of infections caused by Escherichia coli. FQs are broad spectrum antibiotics with high tissue penetration, and ease of use. Therefore, given the concerns existing about drug resistance, we aim to review the latest findings about resistance patterns to levofloxacin (LVX) along with other FQs in E. coli infections in different parts of Iran. Evidence shows that quinolones have been used in Iran for nearly 50 years, and that 0-65% of E. coli isolates show resistance to FQs. In the western parts of Iran, the highest rate of resistance to LVX (66.7%) has been reported among patients having urinary tract infections with E. coli isolates. Few studies and information exist on the antimicrobial resistance of E. coli to LVX in different geographical locations of Iran. However, the findings of various studies on this subject show that E. coli resistance to LVX is more in the western part of Iran than in central and southern regions, but it is similar among inpatients and outpatients. Therefore, it is reasonable advisable to limit the overuse, inappropriate prescription, and self-medication of LVX to prevent the induction of FQ-resistant strains. Accordingly, in order to obtain a clearer image of resistance to FQs, especially LVX in E. coli in Iran, more extensive investigations in different geographical locations and periods of time are required. In addition, antimicrobial stewardship would be helpful in this regard.

Phenotypic and Genotypic Characterization of ESBL-, AmpC-, and Carbapenemase-Producing Klebsiella pneumoniae and Escherichia coli Isolates

OBJECTIVES

Drug resistance among gram-negative bacteria is a worldwide challenge. Due to the importance of drug-resistant Klebsiella pneumoniae and Escherichia coli strains in hospital-acquired infections, we aimed to determine the phenotypic and genotypic characteristics of ESBL-, AmpC-, and carbapenemase-producing isolates obtained from hospitalized patients in Tehran and Ilam (Iran).

MATERIALS AND METHODS

In total, 90 K. pneumoniae isolates and 65 E. coli isolates were collected from various infections. Phenotypic identification of bacterial isolates was performed using standard methods. Phenotypic screening of ESBL, AmpC, and carbapenemase enzymes was carried out. Detection of ESBL, AmpC, and carbapenemase genes was also performed by the PCR method.

RESULTS

Phenotypic detection tests showed that 36 (40%) K. pneumoniae and 23 (35.4%) E. coli isolates were ESBL producers. Moreover, 18 (20%) and 6 (9.2%) K. pneumoniae and E. coli isolates were AmpC producers, respectively. Modified Hodge test results indicated that 39 (43.3%) K. pneumoniae and 18 (27.7%) E. coli isolates produced carbapenemase. Molecular tests showed that 40% of K. pneumoniae and 36.9% of E. coli isolates were ESBL positive. AmpC was detected in 24.4 and 13.8% of K. pneumoniae and E. coli isolates. Carbapenemase was detected in 34 (37.8%) K. pneumoniae and 13 (20%) E. coli isolates. -Conclusion: In this study, 3 K. pneumoniae isolates simultaneously carried ESBL, AmpC, and carbapenemase genes. Up-to-date strategies such as combination therapy or utilization of new antimicrobial agents might help to combat such drug-resistant organisms.

Antimicrobial Resistance Pattern and Spectrum of Multiple-drug-resistant Enterobacteriaceae in Iranian Hospitalized Patients with Cancer

Background:

Nosocomial infections are one of the most leading causes of morbidity and mortality in patients with cancer. The emergence of multiple-drug-resistant (MDR) strains of Gram-negative bacteria causing nosocomial infection has become a serious concern in cancer patients. Therefore, the present study aimed to determine the spectrum and antibiotic resistance pattern of Gram-negative bacteria related nosocomial infections among Iranian cancer patients.

Materials and Methods:

This descriptive cross-sectional study was conducted during the 6 months from December 2015 to May 2016 in two tertiary care centers located in Isfahan and Arak Province. Gram-negative bacteria obtained from different clinical specimens from hospitalized patients with cancer and were identified using standard microbiological methods. Antibiotic susceptibility pattern was determined by the disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) recommendation.

Results:

Of totally 259 culture positive cases, Escherichia coli showed the highest isolation rate (60.6%) followed by Klebsiella pneumoniae (26.6%) and Proteus spp (11.2%). The rate of MDR isolates were 91.5% (237/259). Overall, the most frequent source of bacterial isolation was urinary tract infection (65.6%) followed by skin and soft-tissue infection (23.6%). The antibiotic susceptibility results showed meropenem (MEN) and ceftazidime as the most effective antibiotics for E. coli, K. pneumoniae, and Proteus spp. isolates. Moreover, MEN was the most effective antibiotic against MDR isolates.

Conclusion:

The study findings showed a significant distribution of MDR Gram-negative bacteria which may increase the burden of healthcare-associated infections in cancer patients. Although, carbapenem can be considered as effective agents toward MDR strains for empirical antibiotic therapy in our region.