Antimicrobial Susceptibility Profiles among Pseudomonas aeruginosa Isolated from Professional SCUBA Divers with Otitis Externa, Swimming Pools and the Ocean at a Diving Operation in South Africa

SCUBA divers are predisposed to otitis externa caused by Pseudomonas aeruginosa, which is becoming increasingly multi-drug resistant (MDR). The present work assessed the antibiotic resistance profiles of P. aeruginosa obtained from SCUBA divers and their environment in Sodwana Bay, South Africa. Bacterial isolates from a total of 137 random water and ear swab samples were identified using biochemical and molecular methods. P. aeruginosa strains were further evaluated for antibiotic susceptibility using the Kirby–Bauer assay. Double disk synergy test (DDST) to confirm metallo-β-lactamase (MBL) production and PCR amplification of specific antibiotic resistance genes was performed. All (100%) 22 P. aeruginosa isolates recovered were resistant to 6 of the β-lactams tested including imipenem but exhibited susceptibility to trimethoprim–sulfamethoxazole. MBL production was observed in 77% of isolates while the most prevalent extended-spectrum β-lactamase (ESBL) genes present included blaAmpC (86.9%) followed by blaTEM (82.6%). Sulfonamide resistance was largely encoded by sul1 (63.6%) and sul2 (77.3%) genes with a high abundance of class 1 integrons (77.3%) of which 18.2% carried both Intl1 and Intl2. P. aeruginosa found in Sodwana Bay exhibits multi-drug resistance (MDRce) to several pharmaceutically important drugs with the potential to transfer antibiotic resistance to other bacteria if the judicious use of antibiotics for their treatment is not practiced.

The Radial Synergy Test: An Aid to Diagnose de Quervain’s Tenosynovitis

Background: Diagnosis of de Quervain’s tenosynovitis is made clinically. Finkelstein’s and Eichoff’s tests are commonly utilized examination maneuvers. Their specificity has been questioned due to a propensity to provoke pain in asymptomatic patients. Using the principle of synergism, the novel radial synergy test takes advantage of isometric contraction of the first dorsal compartment with resisted abduction of the small finger. Methods: Electromyography was performed on 3 authors and the first dorsal compartment sampled during the maneuver. Sensitivity evaluation was performed via retrospective chart review for patients diagnosed with de Quervain’s from 2013 to 2018. Inclusion criteria were documented radial synergy test, Eichoff’s test, and ≥90% pain relief after lidocaine/corticosteroid injection. We enrolled 222 patients with 254 affected extremities. Specificity evaluation was performed via a prospective cohort of volunteers undergoing radial synergy and Eichoff’s tests. Inclusion criterion was lack of preexisting wrist pain. Score > 0 on Visual Analog Scale was considered positive. We enrolled 48 volunteers with 93 tested extremities. Results: Electromyography revealed positive recruitment of the first dorsal compartment. Sensitivity of the radial synergy test was inferior to Eichoff’s test (97% vs 91%, relative risk [RR] = 0.93 [95% confidence interval [CI] = 0.89-0.97], P < .01). Specificity of the radial synergy test was superior to Eichoff’s test (99% vs 74%, RR = 1.33 [95% CI = 1.18-1.51], P < .001). Conclusions: We describe and evaluate the radial synergy test, a novel examination maneuver to aid the diagnosis of de Quervain’s. This serves as an adjunct for future diagnostic evaluations with its high specificity. Level of Evidence: Level II, diagnostic study.

The Carrier Rate of Extended Spectrum Beta Lactamase (ESBL) Producing Bacteria in Cockroaches (Periplaneta americana) in Hospital and Community

Highlight :Bacteriologically for colonization of ESBL producing Enterobacteriaceae in cockroaches (Periplaneta americana) were analyzed.The prevalence of ESBL producing bacteria among cockroaches in hospitals is bigger than in households.Abstract: Cockroach (Periplaneta americana) is one of the vectors in the environment that can transmit disease. Cockroaches can act as potential mechanical vectors of antibiotic resistant bacteria. Enterobacteriaceae is a gram-negative bacteria that has natural habitats in the digestive tract of humans and animals. Enterobacteriaceae that produce Extended Spectrum β-lactamases (ESBLs) have emerged as major pathogens in hospitals. The study analyzed the prevalence of ESBL producing bacteria in cockroaches that lived in hospitals and residential homes. In this study, a total of 200 cockroaches consisting of 100 cockroaches from the hospital environment and 100 cockroaches from the residential environment were analyzed bacteriologically for colonization of ESBL producing Enterobacteriaceae. The specimen of the alimentary tract was taken and sub-cultured in MacConkey agar supplemented with cefotaxime 2 ug/ml. Growth colonies were suggested as an ESBL-producing bacteria, then were confirmed as ESBL producers by the Double Disk Synergy Test (DDST). The ESBL gene was detected by Polymerase Chain Reaction (PCR). Among 100 household cockroach samples, 14 (14%) were identified as ESBL producers, while 100 hospital cockroaches were 26 (26%) positive ESBL. The ESBL gene, in hospital cockroach were identified of CTXM 19 (19%), SHV 7 (7%), and not any TEM gene, while among household cockroaches were identified CTXM 2 (2%), SHV 11 (11%), and also not detected TEM ESBL gene. Among ESBL genes, only the CTXM gene was significantly different between household and hospital cockroaches.

Characterisation of AmpC / ESBL genes in some pathogen gram-negatives isolated from clinical cases of livestock and companion animals

This study was aimed to search and characterize the AmpC and/or ESBL genes of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from clinical cases of local livestock and companion animals between 2017 and 2019. A total of eight ceftiofur-resistant E. coli (n= 7) and ceftiofur-resistant K. pneumoniae (n= 1) and seven P. aeruginosa were isolated from different cases in local animals. By combination disc method, six E. coli isolates and one K. pneumoniae isolate were found to be ESBL producers. By combination of the disc method and double disc synergy test, no P. aeruginosa isolates were found as ESBL producers. In the agar disc diffusion test (ADDT) performed with cefoxitin and cefoxitin-boronic, only one E. coli was determined as AmpC producer. In ESBL-producing isolates, only the CTX-M class gene was detected by polymerase chain reaction (PCR) and subsequent sequence analysis revealed CTX-M-3 and CTX-M-15 variants. An AmpC positive E. coli isolate was found to carry plasmidic ampC gene in cmy-2 variant from CIT family. It was observed that P. aeruginosa isolates did not carry the plasmidic ampC gene. After the chromosomal ampC gene of one P. aeruginosa was amplified by PCR and sequenced, R79Q and T105A mutations in the chromosomal ampC gene was revealed. This showed that overproduction of the ampC enzyme is involved in the resistance to β-lactams in P. aeruginosa isolates in the study.

Genome-Wide Identification of Carbapenem-Resistant Gram- Negative Bacterial (CR-GNB) Isolates Retrieved From Hospitalized Patients in Bihar, India

Carbapenemase-producing clinical isolates are becoming more common over the world, posing a severe public health danger, particularly in developing nations like India. Carbapenem-resistant Gram-negative bacterial (CR-GNB) infection has become a fast-expending global threat with limited antibiotic choice and significant mortality. The aim of this study was to highlight the carbapenem-resistance among clinical isolates of hospital admitted patients in Bihar, India. A cross-sectional study was conducted with 101 clinical isolates of E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa. All GNB isolates were tested for their antimicrobial susceptibility using double disc synergy test / modified hodge test (DDST/MHT) and subsequently confirmed carbapenemase-producing isolates were evaluated for carbapenem-resistance genes using whole-genome sequencing (genotypically) method. The overall percentage of carbapenem-resistance among GNB was (17/101) 16.83%. The AMR analysis demonstrates a significantly high prevalence of blaCTX−M followed by blaSHV, blaTEM, blaOXA and blaNDM β-lactams carbapenem-resistance genes among clinical isolates of GNB. Co-occurrence of carbapenemase-encoding genes with blaNDM was found in 70.6% of carbapenemase-producing isolates. Our study highlights the mechanism of carbapenem-resistance to curb the overwhelming threat posed by emergence of drug-resistance in India.

Molecular characterization of NDM-1-producing Pseudomonas aeruginosa isolates from hospitalized patients in Iran

Background The emergence of carbapenem-resistant Pseudomonas aeruginosa is one of the most important challenges in a healthcare setting. The aim of this study is double-locus sequence typing (DLST) typing of blaNDM-1 positive P. aeruginosa isolates. Methods Twenty-nine blaNDM-1 positive isolates were collected during three years of study from different cities in Iran. Modified hodge test (MHT), double-disk synergy test (DDST) and double-disk potentiation test (DDPT) was performed for detection of carbapenemase and metallo-beta-lactamase (MBL) producing blaNDM-1 positive P. aeruginosa isolates. The antibiotic resistance genes were considered by PCR method. Clonal relationship of blaNDM-1 positive was also characterized using DLST method. Results Antibiotic susceptibility pattern showed that all isolates were resistant to imipenem and ertapenem. DDST and DDPT revealed that 15/29 (51.8%) and 26 (89.7%) of blaNDM-1 positive isolates were MBL producing isolates, respectively. The presence of blaOXA-10,blaVIM-2, blaIMP-1 and blaSPM genes were detected in 86.2%, 41.4%, 34.5% and 3.5% isolates, respectively. DLST typing results revealed the main cluster were DLST 25-11 with 13 infected or colonized patients. Conclusions The presence of blaNDM-1 gene with other MBLs encoding genes in P. aeruginosa is a potential challenge in the treatment of microorganism infections. DLST showed partial diversity among 29 blaNDM-1 positive isolates.

The Antibiotic Resistance Pattern and Prevalence of blaTEM, blaSHV, blaCTX-M, blaPSE-1, sipB/C, and cmlA/tetR Genes in Salmonella typhimurium Isolated from Children with Diarrhea in Tabriz, Iran

Background: Salmonella gastroenteritis is a global health concern. Recently, increased resistance to Salmonella typhimurium has been reported in several countries. Objectives: The present study aimed to evaluate the prevalence of blaTEM, blaSHV, blaCTX-M, blaPSE-1, sipB/C, and cmlA/tetR genes in S. typhimurium isolates and determine their antibiotic resistance. Methods: This cross-sectional descriptive study was conducted on 110 fecal samples, which were collected from the patients referred to the hospitals and medical centers in Tabriz, Iran during eight months. After phenotypic identification, the antibiogram test and double-disc synergy test were performed on the isolates. Following that, the prevalence of resistance genes was evaluated using multiplex PCR and specific primers. Results: Out of 110 fecal samples, 26 samples (23.63%) were positive for S. typhimurium. The highest resistance of the isolates was against ceftazidime, cefotaxime, amikacin, and tetracycline (100%), and the lowest resistance was against imipenem (3.85%) and nalidixic acid (7.69%). In total, 15 S. typhimurium isolates (57.69%) were positive for the extended-spectrum beta-lactamases. In addition, the most common resistance genes in the isolates were cmlA/tetR (38.46%), blaTEM (34.61%), and blaCTX-M (26.92%). Four isolates (15.38%) carried sipB, three isolates (11.53%) contained blaSHV, and two isolates (7.69%) carried blaPSE-1. Conclusions: The obtained results indicated the high prevalence of antibiotic-resistant S. typhimurium. Therefore, the identification of resistance genes is an important strategy for identifying and counteracting antibiotic resistance.

Prevalence and molecular characterization of extended spectrum beta-lactamase producing uropathogenic Escherichia coli in a tertiary health care facility in Anambra State, Nigeria

Background: The prevalence of ESBLs-producing Escherichia coli has recently increased worldwide due to the expression of ESBL genes which had led to high rate of multidrug resistance antibiotics. Aim: To determine the antimicrobial susceptibility patterns of E. coli isolates and evaluating the ESBL carriage of these isolates at phenotypic and genotypic levels. Methods: One hundred and two clinical Escherichia coli isolates were recovered from UTI suspects and analyzed for ESBL production at phenotypic and genotypic levels using Modified Double Disc Synergy Test and Polymerase Chain Reaction respectively. Results: Of the 102 isolates, 100(98.04%) were associated with MDR phenotypes. The isolates showed variable resistance to all the antibiotics used in the study. The resistance rates were 99.0%, 97.1%, 88.2%, 82.4%, 81.4%, 65.7%, 54.9%, 46.1%, 46.1%, 23.5% for ampicillin, trimethoprim-sulfamethoxazole, ciprofloxacin, ceftriaxone, ceftazidime, amoxicillin-clavulanate, gentamycin, cefoxitin, nitrofurantoin and imipenem, and respectively. The prevalence of phenotypic ESBL production was 74.5%. Based on the PCR results, the randomly selected 20 ESBL-positive isolates possessed one or more ESBLs genes. CTX-M type was the predominant ESBLs type (100%), while those for TEM and SHV-types were 85% and 80% respectively. Four genotype patterns were detected (CTX-M, TEM+CTX-M, SHV+CTX-M and SHV+TEM+CTX-M). The genotype SHV+TEM+CTX-M, was the predominant (70%), followed by the genotype TEM +CTX-M combination (15%). The occurrences of the genotypes, CTX-M and SHV+CTX-M were 5% and 10% respectively. Conclusion: This study found a high rate of Phenotypic ESBL production (74.5%) among the isolates with multidrug resistance, CTX-M as the predominant ESBLs type (100%) and combination of SHV+TEM+CTX-M as the predominant genotype (70%).

Evaluation of different phenotypic diffusion methods in the identification of extended spectrum beta lactamase producing uropathogenic

: The study was aimed to identify the occurrence of extended spectrum of Beta lactamases (ESBLs), to compare different phenotypic methods used for the confirmation and to evaluate the antibiotic resistance pattern in ESBL producing uropathogenic : The strains were isolated from urine and the isolates resistance to at least one of the three representative cephalosporins (cefotaxime, cefpodoxime and ceftazidime) was tested for ESBL production by Double disc synergy test (DDST), Inhibitory potentiated disc diffusion (IPDD) test and quantitative E-strip method.: Of 120strains isolated, 62(51.6%) were resistant to at least one of the three cephalosporins and 28 (45.1%) were positive for ESBL by IPDD and E-strip test. However, 9 (14.5%) strains were positive by DDST method. Among third generation cephalosporins, cefpodoxime was (45.8%) better screening indicator followed by ceftazidime (40.0%) and cefotaxime (37.5%). Most of the ESBL producers (97.3%) were resistant to three or more drugs, compared to (51.2%) non-ESBL producers. : The acceptable method for detection of ESBL producing were IPDD and E-strip tests compared to DDST with better sensitivity (100%), specificity (95.8%) and positive predictive value (96.5%). ESBL producers showed significantly (p&#60;0.05) higher resistance to tobramycin, amoxyclav and amikacin compared to non ESBL producers.

A 3×4 drop-plating protocol for estimation of Antimicrobial-resistant bacteria, taking Extended-spectrum beta-lactamases producing Escherichia coli as an example.

The estimation of antimicrobial-resistant (AMR) bacteria plays an important role in risk assessment and surveillance. To test the concentration of resistant bacteria with colony count is a fast and straightforward way to perform. Here we describe an optimized drop-plating method for colony counting of resistant bacteria. We took the ESBL-producing E. coli in freshwater samples as an example. The optimized methods can successfully quantify ESBL-producing E. coli of water samples in a concentration range of 104 CFU/L to 106 CFU/L. We have shown that this drop-plating method is comparable to the direct spreading method by testing with both methods on a series of simulated samples, which were constructed using raw surface water spiked with different concentrations of ESBL-producing E. coli. The ESBL-producing phenotype has been further confirmed with the double-disc synergy test. Compared to direct spread methods, our methods can save consumables and operate with smaller sample sizes. Therefore, this method could be more sustainable in AMR surveillance and risk assessment.