Assessment of antimicrobial resistance laboratory-based surveillance capacity of hospitals in Zambia: findings and implications for system strengthening.

BACKGROUND: A well-established antimicrobial resistance (AMR) laboratory-based surveillance (LBS) is of utmost importance in a country like Zambia which bears a significant proportion of the world's communicable disease burden. This study assessed the capacity of laboratories in selected hospitals to conduct AMR surveillance in Zambia. METHODS: This cross-sectional exploratory study was conducted among eight purposively selected hospitals in Zambia between August 2023 and December 2023. Data were collected using the self-scoring Laboratory Assessment of Antibiotic Resistance Testing Capacity (LAARC) tool. FINDINGS: Of the assessed facilities, none had full capacity to conduct AMR surveillance with varying capacities ranging from moderate (63% (5/8)) to low (38% (3/8)). Some of the barriers of AMR-LBS were the lack of an electronic laboratory information system (63% (5/8)) and the lack of locally generated antibiograms (75% (6/8)). Quality control for antimicrobial susceptibility testing (AST), pathogen identification and media preparation had the lowest overall score among all of the facilities with a score of 14%, 20% and 44%, respectively. The highest overall scores were in specimen processing (79%), data management (78%), specimen collection, transport and management (71%), and safety (70%). Most facilities had standard operating procedures in place but lacked specimen-specific standard operating procedures. CONCLUSION: The absence of laboratories with full capacity to conduct AMR surveillance hinders efforts to combat AMR and further complicates the treatment outcomes of infectious diseases. Establishing and strengthening LBS systems are essential in quantifying the burden of AMR and supporting the development of local antibiograms and treatment guidelines.

Detection of culturable and nonculturable Legionella species from hot water systems of public buildings in Japan.

AIMS: To investigate the prevalence of culturable and nonculturable Legionella species in hot water systems of public buildings in Japan and assess the risk factors associated with Legionella contamination in hot water systems. METHODS AND RESULTS: Legionella species were detected by conventional culture and molecular methods in 130 water samples collected from 40 buildings. A total of 26 (20.0%) water samples from 17 (42.5%) buildings were positive by culture, qualitative PCR or both methods: Legionella pneumophila and Leg. anisa were detected in four samples by a culture method, whereas 23 samples were positive by qualitative PCR, with the presence of various Legionella species confirmed by sequencing. Of these 23 samples, bacterial counts were quantifiable in 21 by real-time PCR (from 1.7 x 10(5) to 2.6 x 10(11) cells per litre). Phylogenetic analysis of amplified partial 16S rRNA gene showed close relations to various species of Legionella, including Leg. anisa and Leg. micdadei, all of which have been associated with respiratory diseases or increased antibody titres in human sera. Assessment of risk factors showed that turbidity, free chlorine concentration, iron concentration and heterotrophic plate count (HPC) were significantly associated with Legionella contamination (P < 0.05). CONCLUSIONS: Contamination of hot water systems of public buildings with culturable and nonculturable Legionella species may be a potential risk factor for Legionella infection in Japan. Adequate levels of chlorine, low levels of iron and HPC are important maintenance measures in the reduction of Legionella contamination in hot water systems. SIGNIFICANCE AND IMPACT OF THE STUDY: More than 40% of hot water systems in the Japanese public buildings examined were contaminated by not only culturable Leg. pneumophila and Leg. anisa but also by nonculturable pathogenic species. To our knowledge, this is the first report of both culturable and nonculturable Legionella contamination in hot water systems of public buildings in Japan.

Phase transition of a spin-lattice-gas model with two timescales and two temperatures.

We study the phase transition of a nonequilibrium statistical-mechanical model, in which two degrees of freedom with different time scales separated from each other touch their own heat bath. A general condition for finding anomalous negative latent heat recently discovered is derived from a thermodynamic argument. As a specific example, the phase diagram of a spin-lattice-gas model is studied based on a mean-field analysis with the replica method. While configurational variables are spin and particle in this model, it is found that the negative latent heat appears in a parameter region of the model, irrespective of the order of their time scale. Qualitative differences in the phase diagram are also discussed.

Novel Mycobacterium avium Complex Species Isolated From Black Wildebeest (Connochaetes gnou) in South Africa.

A study was undertaken to isolate and characterize Mycobacterium species from black wildebeest suspected of being infected with tuberculosis in South Africa. This led to the discovery of a new Mycobacterium avium complex species, provisionally referred to as the Gnou isolate from black wildebeest (Connochaetes gnou). Sixteen samples from nine black wildebeest were processed for Mycobacterium isolation. Following decontamination, samples were incubated in an ordinary incubator at 37°C on Löwenstein-Jensen slants and in liquid medium tubes using the BACTEC™ MGIT™ 960 system, respectively. Identification of the isolate was carried out by standard biochemical tests and using the line probe assay from the GenoType® CM/AS kit (Hain Lifescience GmbH, Nehren, Germany). The DNA extract was also analysed using gene sequencing. Partial gene sequencing and analysis of 16S rRNA gene, and 16S-23S rRNA (ITS), rpoB and hsp65 and phylogenetic analyses by searching GenBank using the BLAST algorithm were conducted. Phylogenetic trees were constructed using four methods, namely Bayesian inference, maximum likelihood, maximum parsimony and neighbour-joining methods. The isolate was identified as Mycobacterium intracellulare using the GenoType® CM/AS kit and as Mycobacterium avium complex (MAC) by gene sequencing. The gene sequence targeting all the genes, ITS, 16S rRNA, rpoB and hsp65 and phylogenetic analyses indicated that this isolate presented a nucleotide sequence different from all currently published sequences, and its position was far enough from other MAC species to suggest that it might be a new species.

Tuberculosis Caused by Mycobacterium orygis in Dairy Cattle and Captured Monkeys in Bangladesh: a New Scenario of Tuberculosis in South Asia.

Mycobacterium orygis, commonly known as the oryx bacillus and a newly proposed Mycobacterium tuberculosis complex subspecies, was isolated from 18 cattle in a dairy farm and two captured rhesus monkeys in a zoo in Bangladesh. All the infected animals had tuberculosis lesions in their lungs, suggesting transmission and infection with M. orygis by an airborne route. The 20 isolates were analysed using a range of conventional and molecular typing methods, and RD-deletion typing and sequencing of selected genes confirmed the isolates as M. orygis. Multiple-locus variable-number tandem repeat analysis (MLVA) allowed the isolates to be divided into three clusters based on the relatedness of their MLVA profiles. The two monkey isolates shared the same MLVA pattern with 15 of the cattle isolates, whereas the remaining three cattle isolates had different patterns, even though the latter animals had been kept in the same dairy farm. The diversity observed among isolates may suggest the bacteria have been established in this area for a long period. This study along with other recent findings that report the detection of M. orygis from animals as well as humans originating from South Asia potentially indicate endemic distribution of M. orygis in South Asia.

A role of interferon-gamma (IFN-gamma) in tumor immunity: T cells with the capacity to reject tumor cells are generated but fail to migrate to tumor sites in IFN-gamma-deficient mice.

IFN-gamma-deficient (IFN-gamma-/-) mice induce potent in vitro immune responses such as anti-allo mixed lymphocyte reaction and CTL responses, whereas they often fail to exhibit in vivo immunity. Here, we investigated whether there exists a defect in tumor rejection responses and if so, which process of responses is impaired. IFN-gamma-/- and wild-type (WT) BALB/c mice were immunized with attenuated syngeneic CSA1M tumor cells. The capacity of T cells to mediate tumor protection was examined in Winn assays to assess the growth of tumor cells admixed with tumor-sensitized T cells. Splenic T cells from both groups of mice exhibited comparable levels of tumor-neutralizing activity. When portions of immunized mice were directly challenged with viable tumor cells, tumor rejection was induced only in WT mice. CD4(+) and CD8(+) T-cell infiltration were observed at the site of tumor challenge in WT mice, whereas such a T-cell infiltration did not occur in IFN-gamma-/- mice. Similarly, splenic T cells from interleukin 12-treated CSA1M-bearing IFN-gamma-/- and WT mice neutralized tumor cells at comparable efficacies in Winn assays. However, the migration of these T cells to tumor masses and the resultant interleukin 12-induced tumor regression took place in WT mice, but neither intratumoral T-cell infiltration nor tumor regression occurred in IFN-gamma-/- mice. These results indicate a critical requirement for IFN-gamma in the process of inducing T-cell migration to tumor sites rather than of generating antitumor protective T cells.

A critical role for a peritumoral stromal reaction in the induction of T-cell migration responsible for interleukin-12-induced tumor regression.

Interleukin (IL) 12 has been shown to elicit tumor regression when this cytokine induces the migration of T cells to tumor sites. The present study investigates the role of a peritumoral stromal reaction in IL-12-induced T-cell migration. In the CSA1M and OV-HM tumor models, IL-12 treatment induced tumor regression that is associated with T-cell migration. Neither T-cell migration nor tumor regression was observed in the Meth A and MCH-1-A1 models. Stromal tissue containing neovascular blood vessels developed at the peritumoral area of the former two IL-12-responsive tumors but not at the peritumoral area of the latter two IL-12-unresponsive tumors. The significance of stroma development was investigated using a pair of tumor models (CSA1M and a subline derived from CSA1M designated the CSA1M variant), both of which exhibit the same tumor immunogenicity. In contrast to the parental CSA1M cell line, the variant cell line was not responsive to IL-12, and neither stroma development nor T-cell migration was observed, even after IL-12 treatment. Histological analyses revealed that the parental cell line had peritumoral stroma with intrastromal vessels but only a few vessels in tumor parenchyma, whereas the variant cell line showed no stroma but had abundant vasculature in the tumor parenchyma. Most importantly, only stromal vessels in the parental tumors expressed detectable and enhanced levels of vascular cell adhesion molecule 1 (VCAM-1)/ intercellular adhesion molecule 1 (ICAM-1) before and after IL-12 treatment, respectively. In contrast, parenchymal vasculature in the variant cell line failed to express VCAM-1/ICAM-1 even after IL-12 treatment. When transferred into recipient tumor-bearing mice, IL-12-stimulated T cells from the parental CSA1M-bearing or the variant CSA1M-bearing mice migrated into the parental but not into the variant tumor mass. Together with our previous finding that T-cell migration depends on the VCAM-1/ICAM-1 adhesive interactions, the present results indicate a critical role for peritumoral stroma/stromal vasculature in the acceptance of tumor-infiltrating T cells that is a prerequisite for IL-12-induced tumor regression.

Detection of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Market-Ready Chickens in Zambia.

The frequent administering of antibiotics in the treatment of poultry diseases may contribute to emergence of antimicrobial-resistant strains. The objective of this study was to detect the presence of extended-spectrum ß-lactamase- (ESBL-) producing Escherichia coli in poultry in Zambia. A total of 384 poultry samples were collected and analyzed for ESBL-producing Escherichia coli. The cultured E. coli isolates were subjected to antimicrobial susceptibility tests and the polymerase chain reaction for detection of bla CTX-M, bla SHV, and bla TEM genes. Overall 20.1%, 77/384, (95% CI; 43.2-65.5%) of total samples analyzed contained ESBL-producing Escherichia coli. The antimicrobial sensitivity test revealed that 85.7% (66/77; CI: 75.7-92) of ESBL-producing E. coli isolates conferred resistance to beta-lactam and other antimicrobial agents. These results indicate that poultry is a potential reservoir for ESBL-producing Escherichia coli. The presence of ESBL-producing Escherichia coli in poultry destined for human consumption requires strengthening of the antibiotic administering policy. This is important as antibiotic administration in food animals is gaining momentum for improved animal productivity in developing countries such as Zambia.

Involvement of EphA2 in the formation of the tail notochord via interaction with ephrinA1.

Eph receptors have been implicated in cell-to-cell interaction during embryogenesis. We generated EphA2 mutant mice using a gene trap method. Homozygous mutant mice developed short and kinky tails. In situ hybridization using a Brachyury probe found the notochord to be abnormally bifurcated at the caudal end between 11.5 and 12.5 days post coitum. EphA2 was expressed at the tip of the tail notochord, while one of its ligands, ephrinA1, was at the tail bud in normal mice. In contrast, EphA2-deficient notochordal cells were spread broadly into the tail bud. These observations suggest that EphA2 and its ligands are involved in the positioning of the tail notochord through repulsive signals between cells expressing these molecules on the surface.

Log-normal diameter distribution of Pd-based metallic glass droplet and wire.

We have studied the formation of Pd42.5Cu30Ni7.5P20 metallic glass droplets and wires in the gas atomization process. We demonstrate that the sizes of droplets and wires can be distinguished by the Ohnesorge number (Oh), which is the proportion of the spinnability to the capillary instability, and the diameter distributions follow a log-normal distribution function, implying cascade fragmentation. For droplets, the number significantly increases at Oh < 1 but the diameter gradually decreases. For wires, the number greatly increases at Oh > 1 while the diameter steadies below 400 nm. Further, the wire diameter is quadrupled at Oh = 16 due to the high viscosity which suppresses both capillary breakup and ligament elongation.

The effect of non-insulin-dependent diabetes on serum concentrations of tumor-associated carbohydrate antigens of CA19-9, CA-50, and sialyl SSEA-1 in association with the Lewis blood phenotype.

Serum concentrations of the tumor-associated carbohydrate antigens CA19-9, CA-50, and sialyl SSEA-1 were measured in non-insulin-dependent diabetic patients without diseases causing the elevation of those antigens, and the relationship to diabetic conditions was studied. The patients of the Lewis blood group phenotype of Lea (23%) had higher serum CA19-9, CA-50, and sialyl SSEA-1 than those of Leb (67%) and Le(-) (10%). Lea patients with high HbA1c (greater than 10%) had significantly higher serum CA19-9 and CA-50 than those with low HbA1c (less than or equal to 7%). Leb patients with high HbA1c also had elevated CA19-9 and sialyl SSEA-1. In Leb patients, diabetic nephropathy was associated with increased CA19-9 levels. Diabetic retinopathy was also accompanied by high carbohydrate antigens in Leb patients, but the difference was not significant. Leb patients treated with sulfonylurea or insulin had increased CA19-9 and CA-50. The changes in serum concentrations of these carbohydrate antigens might have some relationship not only to the Lewis blood phenotype, but also to diabetes.

Controlled biodistribution of highly lipophilic drugs with various parenteral formulations.

Lipid carrier systems are considered effective for targeting highly lipophilic drugs, but little systematic information about the effect of the physicochemical and pharmaceutical characteristics of drugs and formulations on their performance has been obtained. 3H-Retinoic acid and 14C-cholesteryl oleate with different lipophilicities (log PCoct = 6.6 and 18, respectively) were selected as model drugs and the potential of formulations such as oil in water (o/w) emulsion, micellar solution, and liposomes for controlling their biodistribution was demonstrated. After intravenous injection in mice, 3H-retinoic acid showed similar disposition profiles irrespective of formulation type, suggesting its rapid dissociation from carriers. 14C-Cholesteryl oleate with extremely high lipophilicity revealed widely varied disposition profiles reflecting the distribution patterns of carriers: micellar solution and liposomes showed large AUC values and low hepatic clearances, while the use of emulsion as a carrier resulted in rapid clearance from blood circulation into the liver. The results suggested that these formulations can be used as targeting carriers for lipophilic drugs which, however, should have a sufficiently high lipophilicity of about log PCoct 9-16.

Inhibitory potency of crystal matrix protein on the crystallization of calcium oxalate.

The presence of macromolecular substances is among the multiple factors that may influence the complex process of urinary stone formation. The aim of this study was to evaluate the inhibitory potency of crystal matrix protein (CMP). Purification of CMP consisted of calcium oxalate crystal formation, dissolution of crystals, electrodialysis and high-performance liquid chromatography (HPLC). The inhibitory potency of crystal aggregation was examined by the seed crystal method, the undiluted urine method, and the use of scanning electron microscopy (SEM). CMP showed the protein band of 31 kDa in SDS-PAGE. Anti-CMP polyclonal antibody and antihuman prothrombin antibody cross-reacted well with human prothrombin and CMP in Western blotting. CMP and human prothrombin had high inhibitory potency by the seed crystal method and undiluted urine method. Using SEM, we were able to observe the high inhibitory potency of human prothrombin and undiluted CMP on the aggregation of calcium oxalate crystals.

Sporicidal activities of disinfectants on Paenibacillus larvae.

Sporicidal activities of glutaraldehyde, sodium hypochlorite, povidone iodine, ethylene oxide gas, chlorhexidine gluconate, and didecyl dimethylammonium chloride on wet and dry spores of Paenibacillus larvae (basonym: Bacillus larvae) were evaluated for control of honeybee American foulbrood. Glutaraldehyde was found to have a strong and rapid effect on both the wet and the dry spores among the disinfectants tested.

Biological properties and antibiotic susceptibility of Bacillus larvae originated from American foulbrood of honeybee in Japan.

The biological properties and susceptibility to antimicrobial agents of Bacillus larvae were examined. Twenty-nine strains, 28 isolates from each outbreak of American foulbrood in Japan and a B. larvae type strain (ATCC 9545T) were used. our B. larvae isolates had almost the same biological properties as the type strain. The isolates were more susceptible to penicillins, macrolides and lincomycin, a lincosamide, than other antimicrobials. Microsamicin among the macrolides and ampicillin among the penicillins appeared to be the most effective agents.

Disposition of ampicillin in honeybees and hives.

Disposition profile of ampicillin (ABPC) among honeybees, larvae, honey and royal jelly in a hive after oral dosing to adult bees was studied. Four honeybee colonies were administered the single dose of ABPC at the rate of 30 mg/hive by addition to sugar syrup or pollen substitute (paste) for 1 day intake. The colonies received ABPC in syrup showed high drug residue levels in honey and it lasted over 14 days beyond the detection limit of residual analysis. In the hives given ABPC in paste, relatively low honey residues were found, however, the distributions of the drug in young larvae and jelly which was the food of the larvae were very low. ABPC was considered to be a promising drug for the control of American foulbrood, an important bacterial disease of honeybee larvae, because of its high antibacterial activity to the pathogen, Paenibacillus larvae, and instability of residue in honey as human food. The low distribution in young larvae, the target of the disease, threw a doubt on the efficacy of ABPC for American foulbrood control.

[Isolated hypogastric artery aneurysm ruptured into urinary bladder: a case report].

An 81-year-old man was admitted to our hospital with a complaint of dysuria. He had had a right hypogastric aneurysm repaired three years earlier. Physical examination showed a distended soft abdomen and tender mass about the size of a child's head but no murmur was heard over the mass. An excretory urogram (DIP) showed left hydronephrosis and no excretion from the right kidney. Computerized tomography (CT) showed urinary bladder compressed by the mass on the upper right back side. Cystography showed that the large mass occupied the pelvic region with calcification and communicated with the bladder. After a few days, an operation for the aneurysm was undertaken by the surgical department. Although bilateral ureterolysis was possible, a resection of the aneurysm could not be done. The aneurysm was injected with fibrin adhesive and a bilateral nephrostomy was performed. The renal function has been stable and the size of the aneurysm has remained unchanged for 9 months after the surgery.

[The inhibitory effects of Takusha on the formation, growth and aggregation of calcium oxalate crystals in vitro].

The inhibitory effects of Takusha on the formation, growth and aggregation of calcium oxalate crystals were estimated by the microplate method and the use of Coulter counter TAII in the diluted urine system and undiluted urine system. In the diluted urine system, the inhibitory effect on aggregation and growth was calculated from the changes in the number and volume of crystals by the seed crystal method. Takusha had a strong inhibitory effect on the aggregation and growth when the concentration was above 10 micrograms/ml. In measuring the metastable limit by the microplate method, Takusha had a mild inhibitory effect on the formation of crystals above the concentration of 1 mg/ml. In the undiluted urine system, after determining the metastable limit, the formation and growth of calcium oxalate crystals which precipitated in response to a load of sodium oxalate were measured. Takusha had a strong inhibitory effect on the formation and growth at the concentration of 0.1-1 mg/ml. Takusha had no glycosaminoglicans in the dimethylmethylene blue assay and had an inhibitory effect on aggregation and growth when its molecular weight was over 10,000. Therefore, Takusha might be useful for preventing stones in recurrent stone formers.

[Studies on the modified dimethylmethylene-blue (DMB) method for determining glycosaminoglycans (GAG) in urine].

The measurement of glycosaminoglycans (GAG) in urine is very important because GAG is an essential constituent of urinary diseases. Since previously reported methods of determination of GAG are quite complicated, dangerous or not stable, we developed a very simple and rapid method to estimate the content of GAG in urine using a microplate and microplate reader. An aliquot of diluted urine is mixed with a 1,9, dimethylmethylene blue (DMB) dye. The assay is based on the metachromatic shift in absorption maximum which occurs when sulfated glycosaminoglycans are added to the dye. The recovery of GAG is good. Other urinary compounds such as sugar, protein and blood did not influence the measurement of GAG. A good correlation was obtained between the modified DMB method and Blumenkrantz and Asboe-Hansen's method (r = 0.737, p < 0.001). The accuracy of this method makes it useful for screening urinary diseases.

[Transurethral microwave thermotherapy for benign prostatic hyperplasia].

Transurethral microwave thermotherapy (TUMT) of prostate was administered to 10 patients with bladder outlet obstruction due to benign prostatic hyperplasia. The mean age of the patients was 74.4 years (range 63 to 85). The Prostatron device, which provides microwave heating of the prostate and conductive cooling of the urethra was used, and the prostate was heated with a calculated intraprostatic temperature of 45.5 degrees C for 55 minutes. No anesthesia was required for most of the patients. The clinical effects were evaluated at 4-6 weeks and 3 months after treatment. The symptomatic scores improved in the majority of patients. There was no significant change in prostate volume. The maximum flow rate and average flow rate were increased at 6 weeks and 3 months, but there was no significant change. The only side effects were transient hematuria and short-term obstruction secondary to urethral edema. In comparing TUMT with the transurethral resection of prostate (TUR-P), the maximum flow rate after TUMT was lower than that after TUR-P and the improvement of residual urine after TUMT was lower than that after TUR-P.