Klebsiella Ornithinolytica Research Articles

Optimization of Bioremediation of Crude Oil Polluted Soil through Variation in Moisture Content and Proportion of Augmenting Bacterium and Fungus

Aim: The aim of this study was to enhance bioremediation of crude-oil polluted soil through optimization procedures. Study Design: The Box-Benkhen coded values format and experimental design were used in the design of the study. Place and Duration of Study: The study was carried out in the Microbiology laboratory of the Department of Microbiology, Rivers State University, Nigeria, between February 2024 and July 2024. Methodology: Hydrocarbon utilizing bacteria (HUB) & fungi (HUF) were isolated from crude-oil polluted soil, and screened for hydrocarbon degrading ability (HCDA). HUB and HUF with the highest HCDA were identified and used for bioremediation optimization experiment. In the experiment, different combination of moisture content (MC), and proportion of HUB (pHUB) & HUF (pHUF) were investigated for their effect on extent of hydrocarbon reduction (EoHR). EoHR obtained from the different combinations were fitted using a generalized polynomial model so as to obtain a polynomial equation for predicting EoHR. The equation was used in generating prediction profiles from which the combined values of the 3 parameters that will lead to the highest EoHR was determined. The predicted combined values were implemented in a new setup. A control and a setup enhanced with fertilizer were also prepared. The setups were maintained for 3 weeks. On day 0, 14, and 21 samples were collected and analyzed for total hydrocarbon concentration (THC). Results: The results obtained showed that among the coded isolated HUB and HUF, HB5 and HF1 had the highest HCDA; 36.4% and 4.1% respectively, and were identified phenotypically as Klebsiella ornithinolytica and Aspergillus flavus respectively. The results of the optimization experiment and prediction profiles showed that the highest (68.6%) EoHR was achievable at MC = 20%, pHUB = 10%, and pHUF = 1%. The actual EoHR on day 21 in the optimized, enhanced optimized, and control setups were 60.3, 58.9, and 39.9% respectively. Conclusion: Bioremediation optimization studies is advantageous and should be carried out on crude-oil polluted sites before carrying out bioremediation.

Understanding bacterial diversity, infection dynamics, prevention of antibiotic resistance: an integrated study in an Algerian hospital context.

Bacterial infections, particularly bacteremia, urinary tract infections (UTIs), and pus infections, remain among hospitals' most worrying medical problems. This study aimed to explore bacterial diversity, infection dynamics, and antibiotic resistance profiles of bacterial isolates. We analyzed data from 1750 outpatients and 920 inpatients, of whom 1.6% and 8.47% respectively had various bacterial infections. The analysis revealed that UTIs were the most prevalent at 41.01%, particularly affecting women. UTIs also showed a distinct distribution across admission departments, notably in emergency (23.07%) and pediatric (14.10%) units. The most frequently isolated microorganisms were Escherichia coli (E. coli), followed by Klebsiella ornithinolytica. Skin infections followed UTIs, accounting for 35.88% of cases, more prevalent in men, with Staphylococcus aureus (S. aureus) being the primary pathogen (57%). Gram-negative bacteria (GNB) like E. coli and Pseudomonas aeruginosa contributed significantly to skin infections (43%). Bacteremia cases constituted 11.52% of bacterial infections, predominantly affecting women (67%) and linked to GNB (78%). A comparative study of antibiotic susceptibility profiles revealed more pronounced resistance in GNB strains isolated from inpatients, particularly to antibiotics such as Amoxicillin/clavulanic acid, Tetracyclin, Gentamicin, Chloramphenicol, and Ampicillin. In contrast, strains from ambulatory patients showed greater resistance to Colistin. Gram-positive bacteria from hospitalized patients showed higher resistance to quinolones and cephalosporins, while ambulatory strains showed high resistance to aminoglycosides, macrolides, fluoroquinolones, and penicillin. Furthermore, these analyses identified the most effective antibiotics for the empirical treatment of both community-acquired and nosocomial infections. Ciprofloxacin, aztreonam, and amikacin exhibited low resistance rates among GNB, with gentamicin and chloramphenicol being particularly effective for community-acquired strains. For S. aureus, ciprofloxacin, rifampicin, and cefoxitin were especially effective, with vancomycin showing high efficacy against community-acquired isolates and fosfomycin and chloramphenicol being effective for hospital-acquired strains. These results are essential for guiding antibiotic therapy and improving clinical outcomes, thus contributing to precision medicine and antimicrobial stewardship efforts.

Potential Pathogenicity of Escherichia coli Isolated from the Stools of Healthy Children Suffering from Diarrhea Admitted to Hospitals in Southern Benin

Aims: Infant mortality linked to infectious diseases remains a major public health concern, especially in the context of antibiotic resistance. This work aimed to study the potential pathogenicity of Escherichia coli strains isolated from the stools of children suffering from diarrhea and healthy from 0 to 15 years old admitted to hospitals in southern Benin.
 Methodology: The isolation and characterization of the strains were carried out according to standard microbiology methods. Molecular characterization was carried out by searching for eight virulence factors (Stx1, Stx2, eaeA, bfpB, LT, InVE, IpaH, AggR) and three antibiotic resistance genes (blaTEM, blaSHV, blaCTX -M) by the PCR technique.
 Results: This study shows that 47.06% of the children sampled suffered from diarrhea, against 52.94% who were healthy. A total of 9 species of Enterobacteriaceae were identified in different proportions: Escherichia coli (66.66%), Klebsiella ornithinolytica (13.72%), Klebsiella pneumonia (5.88%), Enterobacter aerogenes (3.92%), Escherichia vulneris (1.96%), Salmonella arizonae (1.96%), Salmonella spp (1.96%), Enterobacter sakazakii (1.96%), Serratia fonticola (1.96%). All E. coli showed total resistance to amoxicillin, ceftazidime, and cefotaxime. In addition, they showed variable resistance to norfloxacin (95.33%), trimethoprim (83.33%), and sulfamethoxazole (95.24%). 70.83% of E. coli strains isolated from apparently healthy children carry resistance genes blaTEM (12.5%), blaSHV (25%), and blaCTX-M (33.33%). While 66.67% of strains of E. coli isolated from children with diarrhea carry resistance genes blaTEM (12.5%), blaSHV (37.5%), and blaCTX-M (16.67%). Only EPEC was isolated and only in diarrheal children, with a frequency of 20.83%.
 Conclusion: The relatively high prevalence of ECD in this study is remarkable, and it highlights the fact that E. coli is an important agent of infectious diarrhea and could be the leading cause of gastroenteritis in Benin.

Effectiveness /Efficacy Degree of Locally Made Hand Sanitizer against Gram-Negative Bacteria (GNB) using Ultraviolet-Visible (UV-VIS) Spectroscopic Signatures

Hand hygiene, particularly hand sanitizing, is essential in reducing infectious disease transmission. The recent outbreak of different diseases such as Ebola and corona virus in Nigeria and other countries around the world both increased public awareness of the practice of hand sanitizing and resulted in the introduction of new products to the market. This study aimed to evaluate the degree of antibacterial effectiveness and efficacy of ten locally made hand sanitizers sold in Akungba Akoko area using agar well diffusion and dilution methods. This study was carried out from April to July, 2022. In this study, 10 alcohol-based hand sanitizers were purchased from the main stores in Akungba Akoko. Among them, 8 liquid based hand sanitizers and among 3gel based hand sanitizers. Efficacy of hand sanitizers were evaluated against some Gram negative bacterial isolates including; Pseudomonas aeruginosa, Enterobacter cloacae, Haemophilia alvei, Serratia odorifera, Proteus sp, Escherichia coli, Salmonella multocida, Salmonella multocida, Klebsiella ornithinolytica and Klebsiella ornithinolytica by agar well diffusion method. Results in this study showed higher inhibitory activity of 70% of the products to the test isolates. In general however, the sanitizers showed good activities, with inhibition of bacteria noted at concentrations as low as 25%. Products tested in this study showed higher zones of inhibition than previously reported, indicating their overall effectiveness. The variations in diffusion and dilution results highlight the effect of texture of the sanitizing product on testing methods and point at a need to properly assess if this could perhaps have any effect in real time on inhibitory activities. The hand sanitizing products tested in this study are suitable in disease prevention. However, regulatory bodies may need to focus on product texture until the effect of this on activity is determined.

Susceptibility and Virulence of Enterobacteriaceae Isolated from Urinary Tract Infections in Benin.

Enterobacteriaceae represent one of the main families of Gram-negative bacilli responsible for serious urinary tract infections (UTIs). The present study aimed to define the resistance profile and the virulence of Enterobacteriaceae strains isolated in urinary tract infections in Benin. A total of 390 urine samples were collected from patients with UTIs, and Enterobacteriaceae strains were isolated according to standard microbiology methods. The API 20E gallery was used for biochemical identification. All the isolated strains were subjected to antimicrobial susceptibility testing using the disc diffusion method. Extended-spectrum beta-lactamase (ESBL) production was investigated using a double-disc synergy test (DDST), and biofilm production was quantified using the microplate method. Multiplex PCR was used to detect uro-virulence genes, namely: PapG, IronB, Sfa, iucD, Hly, FocG, Sat, FyuA and Cnf, using commercially designed primers. More than 26% (103/390) of our samples were contaminated by Enterobacteriaceae strains at different levels. Thus, E. coli (31.07%, 32/103), Serratia marcescens (11.65%, 12/103), Klebsiella ornithinolytica (8.74%, 9/103), Serratia fonticola (7.77%, 8/103) and Enterobacter cloacae (6.80%, 7/103) were identified. Among the isolated strains, 39.81% (41/103) were biofilm-forming, while 5.83% (6/103) were ESBL-producing. Isolates were most resistant to erythromycin, cefixime, ceftriaxone and ampicillin (≥90%) followed by ciprofloxacin, gentamycin, doxycycline and levofloxacin (≥50%), and least resistant to imipenem (27.18%). In regard to virulence genes, Sfa was the most detected (28.15%), followed by IronB (22.23%), iucD (21.36%), Cnf (15.53%), PapG (9.71%), FocG (8.74%), Sat (6.79%), FyuA (5.82%) and Hyl (2.91%). These data may help improve the diagnosis of uropathogenic strains of Enterobacteriaceae, but also in designing effective strategies and measures for the prevention and management of severe, recurrent, or complicated urinary tract infections in Benin.

Identification and Molecular Characterization of Bacteria and Fungi Associated with Three Fresh Edible Mushrooms

Aims: Mushrooms are health-food used as food supplements and fortification but are susceptible to microbial spoilage due to high moisture content and nutrient status. Fresh mushrooms sometimes show signs of spoilage after harvest and makes storage difficult. The objective of the study was to identify and characterize bacteria and fungi associated with three fresh edible mushrooms, under ambient and cold temperatures.
 Methodology: The study was conducted at the Bells University of Technology, Nigeria, between December 2020 and October 2021. Pleurotus ostreatus and Calocybe indica fruitbodies were procured from the Federal Institute of Industrial Research Oshodi while Pleurotus tuber-regium fruitbodies were obtained from sclerotia planted in loamy soil. The fruitbodies were kept at ambient (28oC) and cold (15oC) temperatures respectively. The bacterial and fungal counts on each of the mushrooms were taken at 0,3, 5, and 7 days after harvest. The isolated bacteria were identified by conventional methods; Analytical Profile Index (API) 20E kits (BioMerieux), while Fungi were identified by morphological features and PCR amplification using ITS 1f/ ITS 4r universal primers. 
 Results: The bacterial and fungal counts on the fruitbodies ranged from 5.7 log CFU/ml – 6.3 log CFU/ml and 5.0 log CFU/ml – 5.9 log CFU/ml respectively. Seven genera of bacteria isolated were gram-negative bacteria. At ambient temperature, Pseudomonas aeruginosa, Enterobacter asburiae, Klebsiella oxytoca, Klebsiella ornithinolytica, Serratia marcescens, Chryseobacterium meningosepticum and Cedecea davisae were isolated while Enterobacter cloacae, Enterobacter sakazakii and Citrobacter braakii were isolated at cold temperature. Aspergillus, Penicillium, and Fusarium were isolated at both temperatures while Alternaria was isolated at ambient temperature.
 Conclusion: Isolated bacteria and fungi were mostly enteric pathogens and potential mycotoxin-producing fungi. This is an indication that strict hygiene and control measures should be put in place during the production and storage of these mushrooms in order to improve the quality and food safety of fresh mushrooms in Nigeria.

Prevalence of extended spectrum Beta-Lactamase producing Klebsiella species from patients' specimens in a tertiary teaching hospital in Ile-Ife, Southwest Nigeria.

This study determined the prevalence of ESBL genes amongst Klebsiella species isolated from patients' specimens attending a Tertiary Teaching Hospital, in Ile-Ife, Southwest Nigeria. A cross sectional study of presumptive isolates of Klebsiella (n=180) were collected, after ethical approval in the microbiology laboratory. Isolates were identified to species level by conventional biochemical tests and MicrobactTM 24E Identification Kits. Antibiotic susceptibility testing was performed by the Kirby Bauer's disk diffusion method. ESBL production was detected by the double disc synergy and ESBL genes by the multiplex PCR protocol. The Klebsiella species identified were Klebsiella pneumoniae 95.6%, Klebsiella oxytoca 3.3%, Klebsiella ornithinolytica 0.6% and Klebsiella terrigena 0.6%. The prevalence of ESBL genes among the Klebsiella isolates was 47.2%, and the most common ESBL gene was blaSHV (38.9%), also 75% of the study isolates had MAR index greater than 0.2. The study establishes the prevalence of Extended Spectrum Beta-Lactamase producing Klebsiella sp in the hospital and identified the most prevalent ESBL genes circulating as blaSHV followed by blaTEM and blaCTX-M in this environment. This underscores the need for regular and continuous surveillance of antimicrobial resistance trend as a strong component of the antibiotics stewardship and infection prevention and control programs in the hospital.

Characteristics of Escherichia coli Isolated from Intestinal Microbiota Children of 0-5 Years Old in the Commune of Abomey-Calavi.

Escherichia coli is a commensal bacterium and one of the first bacteria to colonize the digestive tract of newborns after birth. It is characterized by great versatility and metabolic flexibility that allows its survival in different niches. The present study aims at analyzing the diversity of E. coli strains isolated from the intestinal microbiota of children aged from 0 to 5 years in the commune of Abomey-Calavi in Benin. For this purpose, a descriptive and analytical cross-sectional study was conducted. A total of 135 stool samples were collected from the pediatric clinic of Abomey-Calavi. Microbiological analyses were performed according to standard microbiology analytical techniques. The molecular characterization of E. coli was performed by investigating eight genes (dinB, icdA, pabB, polB, putP, trpA, trpB, and uidA) using the PCR technique. The results showed that the average loading rate on stool samples was 3.74 × 107 CFU/g for TAMF. A total of 7 species of bacteria were identified at different proportions: Staphylococcus spp (55.36%), E. coli (14.29%), Klebsiella ornithinolytica (12.5%), Serratia odorifera (5.36%), and Enterobacter aerogenes (5.36%). Interestingly, isolated E. coli presented a resistance of 100% to cefotaxime and aztreonam. In addition, resistances of 95.24% and 50% were observed against erythromycin and nalidixic acid, respectively. The molecular characterization of the isolated E. coli strains allowed us to discover another molecular variation within the isolated strains. Genes encoding the enzymes isocitrate dehydrogenase (icd) and DNA polymerase II (polB) were detected at 96.30% in the isolated E. coli strains. Moreover, the genes encoding the enzymes beta-D-glucuronidase (uidA) and DNA polymerase (dinB) were detected at 88.89% in the isolated E. coli strains. Interestingly, 81.48%, 85.19, 92.59%, and 100% of isolated E. coli strains expressed the genes encoding the enzymes tryptophan synthase subunit A (trpA), proline permease (putP), p-aminobenzoate synthase, and tryptophan synthase subunit B (trpB), respectively. The diversity of E. coli strains reflects the importance of regulatory mechanisms in the adaptation of bacteria to the gut microbiota.

Survey the Microbial Load in the Tigris River in South of Baghdad City and Some of the Physiochemical Parameters

This study included an analysis of three stations (Al Dora, Al Za'franiya, and Arab Ejbur) chosen to study the Physiochemical and microorganism (Fungi and Bacteria) loud of the Tigris River in the southern section of Baghdad city. The result of this research shows that the highest temperature recorded in summer in Al Za'franiya was 37Co, while the lowest temperature recorded in winter in Al Dora was 9Co. and the value of pH recorded the highest in summer it was 7.9 in Arab Ejbur, and the lowest value was in winter 7.1 in Al Dora regions, While Total Organic Carbon (TOC) shows the highest values found in the summer was 6.7 Mg L-1in Al Za'franiya Samples, and the lowest values were 2.0 Mg L-1in Arab Ejbur during the winter. The more frequently isolated fungi were Aspergillus niger, and the lowest frequently was Chrysosporium was observed during the survey period. At the same time, Bacteriological analysis of water resources showed that Escherichia coli and Pseudomonas aeruginosa were more frequently isolated bacteria and the lowest frequently bacteria were Klebsiella ornithinolytica and Proteus mirabilis. Keywords. Fungi, Bacteria, Temperature, TOC, pH, Tigris River.

A spotlight on Raoultella ornithinolytica: A newly emerging life-threatening zoonotic pathogen

The genus Raoultella contains Raoultella ornithinolytica (R. ornithinolytica), which was previously named as Klebsiella ornithinolytica. R. ornithinolytica is a Gram-negative bacillus that belongs to the family Enterobacteriaceae. This pathogen is normally present in aquaculture, and it has been isolated from fish, insects, and wild and domestic birds. Seafood and poultry products are incriminated as sources of R. ornithinolytica infection. Community-acquired human infection with R. ornithinolytica is common. This infection is commonly associated with sepsis, bacteremia, food poisoning, purities, and urinary and respiratory tracts' infections. Rapid acquired resistance of R. ornithinolytica strains is common, and it is related to the development of resistant genes. R. ornithinolytica is considered as a newly emerging life-threatening pathogen world-wide. Hence, it is very important to determine the role of animals and birds in the epidemiological situation of this pathogen as well as the detection of antibiotic resistance genes before treatment.

A high prevalence of blaOXA-48 in Klebsiella (Raoultella) ornithinolytica and related species in hospital wastewater in South West England.

Klebsiella species occupy a wide range of environmental and animal niches, and occasionally cause opportunistic infections that are resistant to multiple antibiotics. In particular, Klebsiella pneumoniae (Kpne) has gained notoriety as a major nosocomial pathogen, due principally to the rise in non-susceptibility to carbapenems and other beta-lactam antibiotics. Whilst it has been proposed that the urban water cycle facilitates transmission of pathogens between clinical settings and the environment, the level of risk posed by resistant Klebsiella strains in hospital wastewater remains unclear. We used whole genome sequencing (WGS) to compare Klebsiella species in contemporaneous samples of wastewater from an English hospital and influent to the associated wastewater treatment plant (WWTP). As we aimed to characterize representative samples of Klebsiella communities, we did not actively select for antibiotic resistance (other than for ampicillin), nor for specific Klebsiella species. Two species, Kpne and K. ( Raoultella ) ornithinolytica (Korn), were of equal dominance in the hospital wastewater, and four other Klebsiella species were present in low abundance in this sample. In contrast, despite being the species most closely associated with healthcare settings, Kpne was the dominant species within the WWTP influent. In total, 29 % of all isolates harboured the bla OXA-48 gene on a pOXA-48-like plasmid, and these isolates were almost exclusively recovered from the hospital wastewater. This gene was far more common in Korn (68 % of isolates) than in Kpne (3.4 % of isolates). In general plasmid-borne, but not chromosomal, resistance genes were significantly enriched in the hospital wastewater sample. These data implicate hospital wastewater as an important reservoir for antibiotic-resistant Klebsiella , and point to an unsuspected role of species within the Raoultella group in the maintenance and dissemination of plasmid-borne bla OXA-48. This article contains data hosted by Microreact.

Antibiotics Resistant Genes and Plasmid curing of Multidrug Resistant Clinical Bacterial Isolates from the Three Geographical Regions of Ondo State, Nigeria

This study shows the characteristics of multidrug resistant clinical isolates analyzed for their antibiotic resistant genes in laboratory. Genomic DNA was then extracted from each sample using Column-pure Bacteria Genomic DNA Isolation kit. Similarly, plasmid profile, plasmid curing and the antibiotic susceptibility profile of thirty two (32) cultured multidrug resistant clinical isolates were analyzed for their antibiotic resistant genes. The bacterial species tested are Acinetobacter haemolyticus, Budricia aquatic, Burkhoderia cepacia, Citrobacter gilleric, Enterobacter gergoriac,Enterobacter agglomerane, Escherichia coli, Escherichia hermamii, Klebsiella oxytoca, Klebsiella ornithinolytica, Klebsiella terrigena, Pseudomonas aeruginosa, Pseudomonas fluorescens, Staphylococcus spp., Staphylococcus aureus and coagulase –ve, Staphylococcus spp. Nutrient agar and Mueller Hinton Agar were used routinely during the study. The genomic test done on the thirty two (32) multidrug resistant strains did not show any resistant gene. But, the molecular plasmid profile conducted shows that all the isolates possess plasmid. Plasmid curing done reduces the antibiotics resistance nature of the isolates. This shows that the resistance of the isolates were plasmid mediated. The re-assessment of the antibiotic susceptibility profile of the clinical bacterial isolates tested confirmed this. It was also clarified in this study that most of the selected resistant bacterial strains isolated from hospitals were susceptible to medicinal plants such as Moringa oleifera and Andrographis peniculata tested on them. This implies that the use of appropriate medicinal plants can be optimized for pharmaceutical purpose to overcome infections caused by these aetiologic agents.

Raoultella ornithinolytica: Emergence and Resistance.

Raoultella ornithinolytica is an encapsulated Gram-negative, oxidase-negative, catalase-positive, aerobic, non-motile rod that belongs to the Enterobacteriaceae family. This bacterium was initially classified in the genus Klebsiella as Klebsiella ornithinolytica, until the creation of the genus Raoultella in 2001. R. ornithinolytica is usually found in water environments and soil, and due to its ability to convert histidine to histamine, it has been associated with histamine poisoning in humans. R. ornithinolytica is an emerging entity in human infections, with several reports of virulent infections in comorbid at-risk patients. Increasing reports are potentially due to better and more precise identification tools. The objective of this article is to provide a comprehensive review of reported cases of R. ornithinolytica infections, the emergent virulence of described multiresistant strains, and an overview of currently used identification methods.

The hydrophobicity of enterobacteria and their co-aggregation with Enterococcus faecalis isolated from Serbian cheese.

In this paper, we investigated the hydrophobicity, ability to adhere to solvents and the pig epithelium and co-aggregation of members of family Enterobacteriaceae and Enterococcus faecalis KGPMF 49. The bacteria used in this study were isolated from traditionally made autochthonous cheese from Southeastern Serbia (Sokobanja). The percentage of adhered bacteria was different in three solvents (chloroform, ethyl acetate and xylene). The highest percentage was detected in the presence of chloroform, and the lowest percentage was detected in the presence of xylene (chloroform < ethyl acetate < xylene). A different degree of co-aggregation of enterobacteria with E. faecalis KGPMF 49 was observed. Klebsiella ornithinolytica KGPMF 8 demonstrated the highest percentage of co-aggregation with E. faecalis KGPMF49 (32.29%). Klebsiella pneumoniae KGPMF 13, K. ornithinolytica KGPMF 9 and Serratia marcescens biogp 1 KGPMF 19 were found to have the ability to adhere to the pig epithelium, whereas Escherichia coli KGPMF 22 showed no such ability. The ability to co-aggregate with other species and the ability to adhere to the pig epithelium are very important characteristics of the isolated bacteria.

Spectroscopic and Thermal Investigation of Silver Nanoparticle Dispersed Biopolymer Matrix Bovine Serum Albumin: A Promising Antimicrobial Agent against the Pathogenic Bacterial Strains

The present work describes the synthesis of the polypeptide coated silver nanoparticles by the excellent combination of the macromolecule bovine serum albumin (BSA) and nanosized silver particles (AgNPs). The product was characterised by spectroscopic, microscopic and X-ray diffraction analyses. The thermal characteristics were studied by TG-DTG and DSC measurements. The developed system was evaluated for its antibacterial property by disc diffusion method against the selected pathogenic gram positive and gram negative bacterial strains Streptococcus haemolyticus (+ve), Corynebacterium diphtheriae (+ve), Klebsiella ornithinolytica (-ve) and Salmonella paratyphi (-ve). The study revealed that the AgNP-BSA aggregates displayed appreciable thermal stability and better antimicrobial efficacy and is anticipated to be a promising material for antimicrobial applications.

Prevalence of multidrug-resistant Gram-negative pathogens isolated from febrile neutropenic cancer patients with bloodstream infections in Egypt and new synergistic antibiotic combinations.

IntroductionBloodstream infections with multidrug-resistant (MDR) Gram-negative bacteria (GNB) are among the most frequent complications in immunocompromised cancer patients because of their considerable morbidity and mortality. Several guidelines on antimicrobial therapy have addressed empirical treatment for such serious infections; however, the emergence of microbial resistance has become a significant problem worldwide.Materials and methodsIn this study, starting from November 2015 to October 2016, a total of 529 blood specimens were collected from febrile neutropenic cancer patients at a tertiary care cancer hospital in Egypt.ResultsOn examination for positive bacterial growth, it was found that 334 specimens showed no growth, while 195 were positive. Out of the 195 positive culture specimens, 102 (102/195, 52.3%) were Gram-negative and 93 (93/195, 47.7%) were Gram-positive. Out of the 102 GNB, 70 (70/102, 68.6%) were MDR, including Escherichia coli (27/70, 38.6%), Klebsiella pneumoniae (24/70, 34.3%), Acinetobacter baumannii (9/70, 12.8%), Enterobacter cloacae (4/70, 5.7%), Pseudomonas aeruginosa (2/70, 2.8%), Klebsiella oxytoca (2/70, 2.8%), and Klebsiella ornithinolytica (2/70, 2.8%). All MDR GNB showed high resistance to ampicillin, cefepime, ceftriaxone, and cephradine (minimum inhibitory concentration at which 50% of the isolates were inhibited [MIC50] >512 μg/mL for each). However, they showed good susceptibility to colistin (MIC50 <1 μg/mL). The most common extended-spectrum β-lactamases (ESBLs) genes detected were ctx-m (39/70, 55.7%), shv (31/70, 44.3%), and tem (22/70, 31.4%). The most common aminoglycoside-resistant gene detected was aac(6′)-Ib (42/70, 60%) followed by the plasmid-mediated quinolone resistance determinants; qnrA (2/70, 2.8%), qnrB (9/70, 12.8%), and qnrS (19/70, 27.1%). ESBL determinants were significantly associated with resistance to ciprofloxacin, levofloxacin, amikacin, and carbapenems (P-value <0.005). The fractional inhibitory concentration index for ampicillin/sulbactam plus ceftriaxone, ampicillin/sulbactam plus amikacin, and amikacin plus levofloxacin showed synergism against 29 (29/70, 41.4%), 19 (19/70, 27.1%), and 11 (11/70, 15.7%) isolates of the tested MDR GNB isolates, respectively.ConclusionAccordingly, new empirical antibiotics should be administered including the use of colistin or meropenem alone or both against the MDR GNB in neutropenic cancer patients.

Characterization of lactic acid bacteria isolated from traditionally made Serbian Cheese and evaluation of their antagonistic potential against Enterobacteriaceae

In this article, the presence and physiological characteristics of lactic acid bacteria (LAB) isolated from traditionally made cheese from Southeastern Serbia were examined. Three samples, from different households, were obtained in spring. The screening of antagonistic potentials, using agar-well diffusion method, was evaluated. Briefly, three different genera of LAB (Enterococcus [32%], Lactococcus [53%], and Lactobacillus [15%]) were identified. The members of the genus Enterococcus were Enterococcus faecium and Enterococcus faecalis. The member of genus Lactococcus was Lactococcus lactis subsp. lactis var. diacetylactis. The members of genus Lactobacillus were Lactobacillus fermentum, Lactobacillus plantarum, and Lactobacillus paracasei subsp. paracasei. The antagonism of LAB on the growth of Escherichia coli ATCC 25922, Proteus mirabilis ATCC 12453, Klebsiella oxytoca KGPMF1, Klebsiella ornithinolytica KGPMF8, and Aeromonas hydrophila was examined. All tested isolates inhibited the growth of at least one indicator strain with growth inhibition zone from 10 to 21 mm. Results indicated that LAB demonstrated the potential of food biopreservation. Practical applications Traditionally made cheeses represent excellent source of unexplored microflora, especially of autochthonous lactic acid bacteria (LAB). In cheese from Sokobanja, the isolated LAB genera were Lactobacillus sp., Lactococcus sp., and Enterococcus sp. Also, the physiological activity of LAB, as well as their interaction with enterobacteria, which also was isolated from the mentioned cheese, was investigated. The results of this study demonstrated potential of LAB to interact agonistically with the growth of enterobacteria, which was important due to the well-known fact that enterobacteria could affect the organoleptic properties of cheese. LAB showed potential of food biopreservation. Further investigation should include antagonistic potential related to food-borne bacteria and the mechanisms of action.

Isolation and identification of Enterobacteriaceae from traditional Serbian cheese and their physiological characteristics

AbstractIn this paper, the presence of enterobacteria in autochthonous cheese from Southeast Serbia (Sokobanja), made in the traditional way, was investigated. The samples from different households, was taken during the summer and the autumn. Chemical and physical characteristics of samples (water content, fat content, acidity, pH, and sodium chloride content) were examined. In the analyzed samples of cheese, four different genera of family Enterobacteriaceae (Klebsiella [65%], Escherichia [20%], Serratia [10%], and Enterobacter [5%]) were identified. The members of genus Klebsiella were Klebsiella oxytoca, Klebsiella pneumoniae, and Klebsiella ornithinolytica, while in the genus Escherichia only one species, Escherichia coli was identified. Besides, two species of the genus Serratia, Serratia odorifera and Serratia marcescens biogp 1, and one species of the genus Enterobacter, Enterobacter gergoviae, were identified. Biochemical characteristics, proteolytic and lipolytic activity, sensitivity to streptomycin, chloramphenicol, and tetracycline were, also, determined. According to the rapid latex agglutination test, of the four E. coli isolates, two isolates belong to serotype E. coli O157.Practical applicationsThe results of this study contribute to better understanding of unexplored microflora of cheese from Sokobanja. The isolated genera were Klebsiella sp., Escherichia sp., Enterobacter sp., and Serratia sp. with twenty identified species. It is well known that bacteria from family Enterobacteriaceae could affect organoleptic properties of cheese. Bacteria isolated from cheese from Sokobanja mostly did not manifest proteolytic and lipolytic activity. The most number of isolates were susceptible to tested antibiotics. Further researches may contribute to better understanding of interaction between enterobacteria and lactic acid bacteria in autochthonous cheeses.

Laurus nobilis, Zingiber officinale and Anethum graveolens Essential Oils: Composition, Antioxidant and Antibacterial Activities against Bacteria Isolated from Fish and Shellfish.

Several bacterial strains were isolated from wild and reared fish and shellfish. The identification of these strains showed the dominance of the Aeromonas hydrophila species in all seafood samples, followed by Staphylococcus spp., Vibrio alginolyticus, Enterobacter cloacae, Klebsiella ornithinolytica, Klebsiella oxytoca and Serratia odorifera. The isolates were studied for their ability to produce exoenzymes and biofilms. The chemical composition of the essential oils from Laurus nobilis leaves, Zingiber officinale rhizomes and Anethum graveolens aerial parts was studied by GC and GC/MS. The essential oils’ antioxidant and antibacterial activities against the isolated microorganisms were studied. Low concentrations of the three essential oils were needed to inhibit the growth of the selected bacteria and the lowest MBCs values were obtained for the laurel essential oil. The selected essential oils can be used as a good natural preservative in fish food due to their antioxidant and antibacterial activities.

Bacteriological Assessment of Soil Contaminated with Cement Dust

The bacterial population and diversity in soil around a cement plant were assessed at two different sites. Site A (test site) was covered with cement dust, while site B (control site) was free of cement dust. Four soil samples were collected from the surface and below the surface at both sites and their bacterial density and diversity quantified. The bacteriological assessment were carried out using standard methods of analyses. The highest bacterial count of 209.33 x 104 was observed in surface soil sample in site B, while the least count of 66.00 x 104 was observed in soil sample obtained below the surface at site A. A total of 12 bacterial isolates were characterized which include; Micrococcus species, Kleibsella oxytoca, Clustridium species, Proteus mirabilis, Enterobacter cloacae, Citrobacter species, Cryseobacterium meningosepticum, Pseudomonas species, Klebsiella ornithinolytica, Pantoea, Acinobacter baumanii, and Serratia liquefaciens. Seven species were Gram- negative bacterial isolates there are; Proteus mirabilis, Enterobacter cloacae, Citrobacter species, Pseudomonas species, Klebsiella ornithinolytica, Pantoea species, Serratia liquefaciens, while five species were Gram-positive bacteria isolates, which includes; Micrococcus species, Klebsiella oxytoca, Clustridium species, Cryseobacterium meningosepticum, Acinobacter baumanii. These results showed that cement dust can reduce the abundance and diversity of soil bacteria. Therefore, there is a need to put in place appropriate pollution prevention and control strategies in the cement plant.